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Abstract: In this paper, we address some computational challenges arising in complex simulation-based design optimization problems. High computational cost, black-box formulation and stochasticity are some of the challenges related to optimization of design problems involving the simulation of complex mathematical models. Solving becomes even more challenging in case of multiple conflicting objectives that must be optimized simultaneously. In such cases, application of multiobjective optimization methods is necessary in order to gain an understanding of which design offers the best possible trade-off. We apply a three-stage solution process to meet the challenges mentioned above. As our case study, we consider the integrated design and control problem in paper mill design where the aim is to decrease the investment cost and enhance the quality of paper on the design level and, at the same time, guarantee the smooth performance of the production system on the operational level. In the first stage of the three-stage solution process, a set of solutions involving different trade-offs is generated with a method suited for computationally expensive multiobjective optimization problems using parallel computing. Then, based on the generated solutions an approximation method is applied to create a computationally inexpensive surrogate problem for the design problem and the surrogate problem is solved in the second stage with an interactive multiobjective optimization method. This stage involves a decision maker and her/his preferences to find the most preferred solution to the surrogate problem. In the third stage, the solution best corresponding that of stage two is found for the original problem. [Copyright &y& Elsevier]

Understanding the effects of water absorption on the geometry of a paper sheet is important for inkjet printing applications, since internal moisture content differences may cause unacceptable out-of-plane deformations. The present work focuses on moisture-induced deformations due to a moisture content that is uniform over the thickness of the sheet. Large enough in-plane differences will cause the sheet to buckle, leading to a wavy pattern at the edges of the sheet. Two approaches are utilized to study this for levels of moisture content up to and including the threshold for buckling. An analytical approach, based on geometrically nonlinear plate theory (von Kármán theory), and a numerical one, using commercially available finite element software, are presented. As a first reference problem an isotropic circular plate, wetted uniformly at its center, is solved both analytically and numerically for the in-plane stress distribution, the buckling threshold, and the resulting buckling mode. Secondly, the same is done for an orthotropic rectangular plate, wetted at its edges. Here, in the analytical approach a Rayleigh–Ritz analysis is employed to approximate the buckling threshold. The latter is also calculated by numerical means. The results show that the methods provide results consistent with each other. [ABSTRACT FROM AUTHOR]

Abstract: Compared to traditional steel metering blades commonly used in paper coating operations, ‘soft-tip’ metering blades have received considerably less attention. The research presented herein concerns computationally detailing the characteristics of deformation and deflection in soft-tipped blades under the influence of coating colour flow. Multiphysics simulations were conducted to assess the interrelationships between deflection, deformation, blade length and material properties. Localised plastic deformation in the soft-tip material may be manipulated by adjusting the material properties and geometries of the tip material alongside variables such as; the free blade length, the speed and the properties of the incoming coating. Design of soft-tip materials with respect to these factors may make it easier to achieve a desired blade tip and hence, coating characteristic. [Copyright &y& Elsevier]

A three-dimensional model of the steam ejector heat pump for the dryer section of the paper machine was developed by applying the Computational Fluid Dynamics (CFD) technique, which provided the pressure and velocity distributions of fluid flow in heat pump. The results indicated that the fluid velocity field in heat pump has an incomplete axially symmetrical distribution. The entrainment ratio of the heat pump initially increases rapidly with the increase of the ejected steam inlet pressure and then decreases after the inlet pressure exceeds one certain value. There exists a critical value for the mixed fluid pressure under the given operating conditions. The optimal ratio of the diameter of constant area mixing section to the steam nozzle throat diameter is about 3.4 and the optimal ratio of length to diameter of constant area mixing section L/D m is 6. An optimal divergence angle of diffuser was observed under different diffuser length. There is an optimized steam nozzle position under the given operating condition where the maximum of entrainment ratio was observed. The CFD technique is found to be an efficient alternative to predict the ejector performance and the conclusions of the research can provide a beneficial reference for structural optimization design of ejector. [ABSTRACT FROM AUTHOR]

Cellulose partially converted to dialcohol cellulose has been identified as a potential breakthrough material for the production of bio-based, complex, double-curved surfaces due to its extensive strain-at-break characteristics (reaching as great as 80% in tensile loading). Tensile testing of handsheets made from modified cellulose fibers was conducted from 50 to 90% relative humidity (RH) and from 23 to 150 °C. Strain-at-break of the handsheets ranged from 35 to 80% over this humidity and temperature range, which is significantly greater than typical cellulose-based materials. The combined effect of moisture and temperature was further investigated by dynamic mechanical thermal analysis, which was utilized to determine the glass-transition temperature of the handsheets as a function of relative humidity. Based on the tensile test results and verified by the three-dimensional (3-D) forming and simulation, a forming limit diagram (strain-based failure surface which describes and illustrates the formability of the material) for the handsheets was generated. This forming limit illustrates significant extent to which this bio-based material can be 3-D formed into advanced structures. Furthermore, temperature was identified as the best, quickest, and most controllable method of improving extensibility of this material during 3-D forming. [ABSTRACT FROM AUTHOR]

Abstract: Depending on unique operation characteristics for voltage applied on valve side winding of the converter transformers, it is extraordinarily significant to study the partial discharge (PD) behavior with oil-paper insulation under combined AC–DC voltage. Therefore, this paper investigated PD inception characteristics by pulse current methods with needle-plate electrode system under combined AC–DC voltage. Furthermore, 3D electric field distributions versus combined AC–DC voltage in different ratios were calculated by Finite Element Analysis (FEA). An experimental conclusion was drew that AC partial discharge inception voltage (PDIV) in pure oil would decrease linearly with the DC component increasing but the inception voltage with oil-paper insulation appeared to be independent of DC voltage and dependent of AC voltage. And 3D electric field distribution deduced from simulation provided a supplementary proof on the experimental results. Moreover, high speed photography was used to capture emitted light produced by discharge, estimate streamer velocity (1.8 km/s) and record streamer initiation and propagation process in oil gap. Previous studies have shown that the prebreakdown phenomena involving the generation and propagation of vapor channels through the oil could be divided into a three-stage process. [Copyright &y& Elsevier]

Abstract: Recycling activities have demonstrated a remarkable increase over the last decade due to the economic and environmental dimensions of sustainability. In particular, capacity planning in production facilities has become a strategic issue of key importance affecting the profitability of the recycling industry. By integrating the simulation discipline and the feedback control theory into a dynamic consideration of recycling networks, this paper proposes a System Dynamics (SD) model for strategic capacity planning in the recycling industry. The decision-making process is based on a balanced tradeoff between profit and capacity utilization for a single producer with closed-loop recycling activities. The SD model captures physical stocks and flows apparent in real-world recycling networks and includes the feedback mechanisms which regulate these flows. When used as an “experimental tool”, the model tests alternative capacity planning policies and demonstrates policy suggestions for the forward and reverse channels, which maximize profitability over a strategic planning horizon. This experimentation is illustrated by using data from a paper producer with recycling activities, as a real-world test case. Extensive simulation runs, investigate the efficiency of a wide range capacity acquisition decisions, using total company profit as the measure of performance. Although such an analysis may differ from one recycling network to another, it has been kept as generic as possible to facilitate its applicability to a wide-spectrum of real-world local, regional or global networks. [Copyright &y& Elsevier]

Abstract: A wide range of mathematical models for multiple effect evaporators in process industry including paper industry are well reported in the literature but not so extensive work on the dynamic behavior of MEE system is available in the literature. In the present study dynamic behavior of multi-effect evaporator system of a paper industry is obtained by disturbing the feed flow rate, feed concentration, live steam temperature and feed temperature. For this purpose an unsteady-state model for the multi-effect evaporator system is developed. Each effect in the process is represented by a number of variables which are related by the energy and material balance equations for the feed, product and vapor flow. A generalized mathematical model which could be applied to any number of effects and all kinds of feeding arrangements like forward feed, backward feed, mixed feed and spilt feed in the MEE system with simple modifications was finally obtained. Finally model for mixed feed sextuple effect falling film evaporators system was solved using MATLAB. For the steady state and dynamic simulation the ‘fsolve’ and ‘ode45’ solvers in MATLAB source code is used respectively. [Copyright &y& Elsevier]

Abstract: Costa''s dirty paper coding (DPC) offers a good framework for precoding for transmission over additive Gaussian channels with additive states non-causally known at the transmitter but not at the receiver. In this paper, rate calculation, error probability analysis and code design for DPC are investigated from a practical point-of-view. Based on Monte-Carlo numerical integration and simulations, we first show that the gap to the full AWGN capacity can be partially bridged using some finite-dimensional lattices with good packing and quantizing properties. Then the difficult problem of codebook selection is addressed through some illustrative examples. Analysis sheds light on the dual roles of “packing” and “shaping” as well as on their inter-connection at finite-dimensional coding, by opposition to the asymptotic case (i.e., infinite dimension) where the two coding components are decoupled. [Copyright &y& Elsevier]

Abstract: Capillary pressures in a carbon paper gas diffusion layer (GDL) having hydrophilic and hydrophobic pores of a polymer electrolyte membrane fuel cell (PEMFC) are investigated by both lattice Boltzmann simulations and experimental measurements. The simulated and measured capillary pressures as a function of water saturation for water drainage and imbibition processes in the GDL are presented and compared. It is shown that the pore-scale simulated drainage and imbibition capillary pressure curves are in good agreement with that obtained by experiment, both indicating the coexistence of hydrophilic and hydrophobic properties in the polytetrafluoroethylene (PTFE) treated carbon paper GDLs. The fitted capillary pressure curves, obtained from this paper, can provide more accurate predictions of the capillary pressure in carbon paper GDLs with non-uniform porosity and wettability than the standard Leverett–Udell relationship which was obtained for soil with more uniform porosity and wettability. [Copyright &y& Elsevier]

Highlights: [•] A dynamic model for longitudinal vibration assisted guillotining of paper is developed. [•] Empirical model of a stack of thin paper material is identified. [•] Novel measurement procedure for determining dynamic behavior for ultrasonic assisted cutting is developed. [•] Simulated cutting forces are in agreement with the experimentally recorded cutting forces. [Copyright &y& Elsevier]

Abstract: This study investigated the effects of bending curvature of simulated e-paper displays (−10cm, plane and 10cm) and ambient illuminance (50, 500, 6000 and 12,000lx) on the visual performance of young and elderly users for simulated electronic-paper displays. In total, 24 people comprising 12 young and 12 elderly users participated in this study. Young users demonstrated significantly enhanced visual performance using the simulated electrophoretic ink (E ink) e-paper display with ambient illuminance set at 50 and 500lx; however, participants did not demonstrate significantly different visual performance using the 2 simulated e-paper displays with ambient illuminance set at 6000 and 12,000lx. The bending curvature did not exhibit significant effects on the visual performance of young participants under various ambient illuminances. The elderly participants exhibited significantly enhanced visual performance using the simulated E ink e-paper display only when ambient illuminance was set at 50lx; however, participants did not exhibit significantly different visual performance using the two simulated e-paper displays with ambient illuminance set at other levels. Elderly users exhibited significantly enhanced visual performance when the bending curvature was set at 10cm, with ambient illuminance set at 50lx. Elderly users also demonstrated significantly enhanced visual performance under bending curvature settings of 10cm and plane, with ambient illuminance set at 500lx. However, the bending curvature of the simulated e-paper did not exhibit significant effects on the visual performance of elderly participants under ambient illuminance settings of 6000 and 12,000lx. [Copyright &y& Elsevier]

Among all public buildings, on account of their educational purpose, school buildings have a major social responsibility. Therefore energy performance in this type of building is of great importance. The overall purpose of this research is to achieve a functional benchmarking, based on the real operation conditions of school buildings, by the exploitation of the results made public, through an intensive literature survey on energy consumptions in schools. The survey was made to gather data that is relative to energy consumption in school buildings, documented in the most diverse fields and units: global energy consumption values, electrical energy consumption; fuel consumption for heating, energy data consumption of schools expressed in annual cost per unit of heated/cooled surface area ($/m 2 ) or per unit of heated/cooled volume ($/m 3 ) or, finally, as the annual cost per student ($/student). The literature was analyzed to determine if a worldwide comparison among the published data could be established. The results suggest that when attempting to determine an energy benchmark some considerations should not be forgotten: standard indoor environmental conditions (IEC) for classrooms (set-point for indoor operative temperature of 20 °C in winter and 26 °C in summer as suggested in EN 15251:2007), electrical and heating consumption values should be kept separately, different education levels usually require different energy consumption values. A good way to normalize heating energy consumption is going through a climatic adjustment based on Heating Degree Days (HDD). For an impartial data comparison, based either on an operating rating or on a simulation carried out for reference conditions, benchmark reference values should be expressed in terms of billed energy data. [ABSTRACT FROM AUTHOR]

We describe a method for characterization of the microstructure of a paper, in terms of the statistical distribution of the effective radii and lengths of the channels between the paper''s fibers, and the average coordination numbers that characterize the connectivity of such channels, both in the main planes of the paper and in the transverse direction perpendicular to these planes. The microstructure of the paper is then represented by a three-dimensional network of interconnected flow channels between the fibers. The geometrical characteristics of the channels, such as their effective radii and lengths, are selected from the statistical distributions obtained by the characterization method, as are the two average coordination numbers. Extensive computer simulations are carried out to compute the effective permeability tensor of the paper, and to investigate the effect of the various microstructural parameters on the tensor. These simulations indicate that the two average coordination numbers, as well as the spatial distribution of the fibers and their length, strongly influence the flow properties of a paper. [Copyright &y& Elsevier]

Multiphysics simulations of solid oxide cell (SOC) require extensive experience and can be labor intensive. This paper reports the first successful implementation of automated multiphysics simulation process for industrial-scale planar SOC stacks. The automation is realized through Python based Ansys SpaceClaim scripting for building geometric model, Python based Ansys Workbench Meshing scripting for setting numerical grids, and Scheme based Ansys Fluent TUI commands for performing multiphysics simulations. The model building process allows for customized dimensions of all stack components and the corresponding edge grid counts. The automation of simulations streamlines all the computational steps in multiphysics modeling. The multiphysics model is shown to agree well with the experimental data. The automated tool is illustrated in a parametric analysis of SOC operations, illuminating the influences of size, shape and thermal boundary on the stack performance. The automation makes the simulations simple and efficient, invaluable for the SOC design and operation analysis. • First realization of automated multiphysics modeling of production-scale SOC stacks. • Techniques for automated high-fidelity geometry model building and mesh creation. • Simulation of 6 different sized kW-scale stacks & with different thermal conditions. • Mechanism for the influences of stack size and shape on physical fields revealed. [ABSTRACT FROM AUTHOR]

In the simulation of two-phase flow dominated by surface tension, accurate surface tension modeling is beneficial to better reproduce and understand the mechanism of interphase flow. In this paper, based on an ISPH-FVM coupling framework, three different surface tension models are implemented and tested respectively, including the generally used continuum surface force (CSF) model, the continuous surface stress (CSS) model and the height function (HF) model. In the present ISPH-FVM coupling framework, the ISPH particle approximate interpolation technique combined with a volume fraction correction scheme is employed to ensure the volume conservation in the computational domain during the information transfer between particles and grids. Meanwhile, the three surface tension models are discretized and calculated by the volume fraction defined on the FVM grid. The volume fraction of the FVM grid is obtained by approximate interpolation of ISPH particles within the grid support domain. Several benchmark cases are tested to verify the performance of three surface tension models in the ISPH-FVM coupling method. The results show that the CSF model and CSS model have less spurious currents and better robustness than HF model under the present coupling method. In addition, the CSF model and CSS model can simulate the flow regime involving complex interface topology changes more accurately than HF model. • An ISPH-FVM coupling method is developed to simulate two-phase flows. • The volume conservation is guaranteed during the information transfer. • Three surface tension models are implemented and compared under the present coupling method. • The CSF and CSS model can get relatively small spurious currents than HF model. • The CSF and CSS model perform well in predicting the complex interface topological changes. [ABSTRACT FROM AUTHOR]

The launcher recovery method known as 'In-Air Capturing' is an innovative approach where a winged rocket stage is captured mid-air by an aircraft and subsequently towed back to the launch site. To achieve this, a capturing device attached to a tether is released from the towing aircraft. This device autonomously connects the reusable launch vehicle to the aircraft, while the two vehicles are in proximity. The tether's flexible dynamics have a strong influence on the maneuverability of the capturing device. Thus, it is critical to model the dynamics of the tether to get a realistic understanding and to evaluate feasibility of the concept. However, precise modelling and control of highly flexible systems with large deformations is both challenging and computationally intensive. For engineering applications which involve closed-loop simulations, finding a trade-off between accuracy and computational effort is crucial. In this paper, the tether is modelled as a discretized chain of rigid bodies connected by rotational springs at the joints. The tether along with the capture system is integrated in a simulation model and open loop tests are performed to analyse the system characteristics. The tether properties are studied to find a suited configuration for 'In-Air Capturing'. • Multibody modelling approach for long cable like bodies with large deformation. • Capture system dynamics for the unique 'In-Air Capturing' launcher recovery concept. • Dynamic modelling for the complete capturing system including towing aircraft, capturing device and tether. • Assessment of tether properties suited for 'In-Air Capturing' with sensitivity studies. [ABSTRACT FROM AUTHOR]

Abstract: A new two-dimensional network model is proposed as a micromechanics model to simulate paper’s failure process due to sequentially breakages of fibers and/or bonds. Paper is approximated as a network composed of fibers any two of which link to each other by their intersecting point, namely so-called bond. Fibers distribute along three particular directions, leading to network’s macro-level isotropy. In the framework of finite element method, nodes correspond to fiber-to-fiber bonds, while elements are fiber segments between every two neighboring nodes and described by Timoshenko beam theory. Element breaks when its equivalent internal tensile stress reaches the tensile strength of fiber. Strength of nodes, i.e. fiber-to-fiber bonds is assumed to be dependant on shearing interaction between fibers, considering the dominant interaction is shearing in a plane problem. Numerical examples show the model’s capacity of reflecting basic failure characteristic in paper. Influences of fiber length and the ratio of fiber strength to bond strength are analyzed in detail. [ABSTRACT FROM AUTHOR]

Abstract: Two categories of mathematical models were compared for the simulation of consolidation of paper coating structures, that is for the packing of pigments on a paper substrate under dewatering conditions. The first category uses probabilistic methods, relying on a random number generator to either determine the initial position of the pigments or their motion. The second category uses deterministic methods based on force balances. In this work, two probabilistic models and two deterministic models are described and their respective advantages and drawbacks are critically reviewed. Simulation results obtained using three of these methods are compared for the case of monodisperse and bidisperse spherical suspensions. Porosity calculations of the numerical packings obtained with the (deterministic) discrete element method (DEM) and two probabilistic methods, the Monte-Carlo (MCD) and the steepest descent (SDD) deposition methods, are compared with experimental data from the literature. These calculations reveal significant differences in the pore volume obtained with these three models. An analysis based on the bridging and relaxation phenomena that prevail in the flow of such particulate systems provide an explanation for these differences and show the strong potential of the discrete element method. The choice of the simulation method depends on the objective of the simulations. DEM will provide more accurate predictions of macroscopic quantities such as the porosity or the roughness, but requires very long computational times. MCD or SDD will only provide qualitative trends, but is computationally far less intense. A combination of strategies might be appropriate, using MCD (or SDD) to provide guidelines and DEM to enhance the results predicted by MCD. [Copyright &y& Elsevier]

Paper is a stochastic network of fibres, water and additives, and in that sense it may be envisaged as a composite material. Since fibres are much longer than the thickness of the paper sheet, the network is planar and almost two-dimensional. The two-dimensional structure governs many paper properties but the three-dimensional porous structure is also important. Insight into the structural changes that take place when paper is compressed in the paper machine may be gained by modelling and simulation of its viscoelastoplastic behaviour. The present work describes a mathematical model based on the cellular solids theory, characterising the nonlinear rheologic behaviour of the material. This approach results in an unsteady state problem and the resulting set of ODEs is solved by means of the DLSODES subroutine, which uses an integrator based in the Gear method. Experiments were conducted on a laboratory-scale dynamic press in order to validate the mechanical model. [Copyright &y& Elsevier]

Extensive computer simulations have been carried out to model imbibition of a coating fluid into a paper. The microstructure of the paper''s pore space is represented by a network of interconnected channels or pore throats that are formed between the paper''s fibers. The geometrical characteristics of the channels, such as their effective radius and length, as well as their connectivity, are selected from the experimental data presented in Part II of this series. The imbibition process that we simulate is the result of forcing the coating fluid into the pore space by applying a time-dependent flow-driven pressure distribution to the external surface of the paper, or is driven only by capillary forces. The dynamic pressure distribution is representative of a high-speed coating process. The simulations indicate that the connectivity of the pore throats, the anisotropic structure of the paper''s pore space, and the dynamic pressure distribution all have a strong influence on imbibition of a coating fluid into a paper''s pore space and, hence, on the quality of the coating. [Copyright &y& Elsevier]

Abstract: This paper deals with a perfectly continuously monitored system which gradually and stochastically deteriorates. The system is renewed by a delayed maintenance operation, which is triggered when the measured deterioration level exceeds an alarm threshold. A mathematical model is developed to study the asymptotic behavior of the reliability function. A procedure is proposed which allows us to identify the asymptotic failure rate of the maintained system. Numerical experiments illustrate the efficiency of the proposed procedure and emphasize the relevance of the asymptotic failure rate as an interesting indicator for the evaluation of the control-limit preventive replacement policy. [Copyright &y& Elsevier]

Abstract: We study a novel five-species system on two-dimensional lattices when each species have two superior and two inferior partners. Here we simplify the huge parameter space of predation probability to only two parameters. Both of Monte Carlo simulation and Mean Field Theory reveal that two of strategies may die out when the ratio of the two parameters is close to the golden point 0.618, and the remaining three strategies are provided a cyclic dominance system. [Copyright &y& Elsevier]

Abstract: We prove a theorem for the existence of solutions to a variational problem, under assumptions that do not require the convexity of the integrand. [Copyright &y& Elsevier]

Abstract: We study the deviations for the results of the properties of a hard-sphere gas near the walls of a micro/nano channel using the hybrid MD–MC simulation method compared to the pure MD and MC results. Our model for the micro channel consists of two parallel infinite plates situated at distance L apart from each other, and of gas molecules confined between these two walls. We study the dependence of the deviations for higher densities, considering different lengths of the different simulation domains in the hybrid MD–MC method. We find that when density is increased, the deviations in the pure MC results are increasing compared to pure MD results. The deviations in the hybrid simulation results are decreasing and are very small when increasing the width of the solid–gas interface. The deviations of the pure MC simulation results from the pure MD simulation results for the number density are found to be around 0.9%, when the reduced density and the width of the channel , where λ is the mean free path. When the hybrid method is used, the deviations are decreasing with a factor from two to three, and are between 0.32%–0.42%. For more dense gas (), the deviations of the MC simulation results for the number density are found to be 1.71%, and the deviations of the hybrid MD–MC simulation results between 0.246% and 0.6977%. We discuss how these deviations in case of a dense gas () depend on the width of the interface, and we study it for the case when the MD domain is 10% and MC domain is 90% from the simulation domain, and also for the case when the MD domain is 50% and MC domain 50% from the whole simulation domain. For more dilute gas, the MC, MD and hybrid MC–MD simulations are in very good agreement and the deviations are negligible. [Copyright &y& Elsevier]

The article describes the method of synthesis of the simulation model of pulse converters with the control system, intended for implementation in FPGA. The technique is based on the structural representation of integro-differential and algebraic equations and the method of switching breaking functions. The models you develop allow you to bring modeling time closer to real. The method is described by an example of a solar battery energy conversion channel of an automatic spacecraft power supply system. The paper considers the possibility of implementing a solar-hydrogen energy supply scheme. This concept involves the accumulation of excess energy in the form of chemical energy on board the spacecraft. [ABSTRACT FROM AUTHOR]

This paper presents the high-fidelity physical modeling of a Thrust Vector Control (TVC) system operated by Electro-Mechanical Actuators (EMAs) for Reusable Launch Vehicles (RLVs). In contrast to simplified, often linear, models, high-fidelity physical models enable a better assessment of the actual system performance and a deeper verification of the on-board software robustness against disturbances, unmodeled dynamics or degradation. This aspect is essential to enable the reusability concept as driven by long-term reliability requirements. Moreover, critical systems like Fault Detection, Isolation and Recovery (FDIR) logic, whose robustness and efficacy are often difficult to prove, can be thoroughly tested without requiring hardware experiments with eventual invasive modifications for fault injections. This work captures the whole dynamics of the EMA and TVC components, including the power drive electronics, the electrical motor, and the mechanical transmission for the EMA, as well as the mechanical properties of the engine nozzle acting as a load. The resulting differential algebraic equation system is modeled in the Modelica acausal object-oriented modeling language. An ad-hoc framework is implemented to guarantee flexibility and modularity, which allows models with different fidelity levels to be easily exchanged to achieve the simulation objectives and needed accuracy level. The impact of the different models on the closed-loop TVC dynamics is analyzed in both the frequency and time domain, and then benchmarked with a realistic RLV mission. The results show that the high-fidelity physical models provide a better understanding of the more complex effects governing the TVC dynamics and can, in turn, effectively improve its requirement definition process. • The physical modeling and simulation of an EMA-based TVC system is presented. • High-fidelity physical models help assessing TVC system control software performance. • EMA component models with incremental fidelity levels are proposed. • EMA and TVC system models are integrated in a Modelica-based framework. • Different closed-loop responses are analyzed in the frequency and time domains. [ABSTRACT FROM AUTHOR]

Response to discussion of paper "Numerical generation of inflow turbulence by cell perturbation technique in WRF simulation" by Munoz-Esparza et al. Inflow turbulence generation, Cell perturbation, Atmospheric boundary layers. [Extracted from the article]

Discussion of paper "Numerical generation of inflow turbulence by cell perturbation technique in WRF simulation" by Singh et al. (2020). Inflow turbulence generation, Large-eddy simulation, Cell perturbation method, Atmospheric boundary layers. [Extracted from the article]

Integrated geographic modelling and simulation is a computational means to improve understanding of the environment. With the development of Service Oriented Architecture (SOA) and web technologies, it is possible to conduct open, extensible integrated geographic modelling across a network in which resources can be accessed and integrated, and further distributed geographic simulations can be performed. This open web-distributed modelling and simulation approach is likely to enhance the use of existing resources and can attract diverse participants. With this approach, participants from different physical locations or domains of expertise can perform comprehensive modelling and simulation tasks collaboratively. This paper reviews past integrated modelling and simulation systems, highlighting the associated development challenges when moving to an open web-distributed system. A conceptual framework is proposed to introduce a roadmap from a system design perspective, with potential use cases provided. The four components of this conceptual framework - a set of standards, a resource sharing environment, a collaborative integrated modelling environment, and a distributed simulation environment - are also discussed in detail with the goal of advancing this emerging field. [ABSTRACT FROM AUTHOR]

This paper introduces a flexible framework to enable high-fidelity simulations of the fuel slosh dynamics for verification of the Guidance, Navigation and Control (GNC) algorithms. The sloshing phenomenon must be tackled during the control system design phase and the GNC software run and validated within appropriate simulation frameworks. Equivalent mechanical models can well approximate sloshing under specific assumptions, allowing the derivation of the multibody vehicle's equations of motion; however, while suitable for analysis and control synthesis purposes, this approach presents several limitations for implementation as a simulation model. In this work, the multibody plant embedding slosh dynamics is modeled by means of the DLR's Vertical Landing Vehicles Library (VLVLib) written using the object-oriented Modelica modeling language. The advantages of using Modelica are explored throughout the paper. Given that control synthesis, analyses and simulation campaigns are usually performed in the Matlab/Simulink environment, a core point of the proposed solution is to achieve a good synergy within the latter and the Modelica plant model with the least readaptation burden for the developer. The strategies to achieve a full integration and verification tool chain are illustrated. The potential of this approach is demonstrated via two different test cases: a lunar landing scenario of the ALINA spacecraft developed by PTS, and CALLISTO reusable rocket demonstrator. • A flexible framework to enable high-fidelity simulations of the fuel slosh dynamics for verification of the GNC algorithms is introduced. • The spacecraft model embedding the slosh dynamics is implemented exploiting Modelica language. • A GNC testing framework is obtained with the integration of the causal Simulink environment with the compiled Modelica model. • Two test cases are presented: the ALINA spacecraft lunar landing scenario and CALLISTO reusable Vertical-Takeoff–Vertical-Landing demonstrative mission. [ABSTRACT FROM AUTHOR]

Abstract: In this paper we describe electrophoresis of charged particles in a thin layer of a nonpolar liquid between two insulating substrates because this configuration is common in recently developed in-plane electronic paper. In the in-plane electrophoresis experiments a model system of charged inverse micelles in dodecane has been used which is well understood from studies of out-of-plane electrophoresis. The transient current due to drift and diffusion of charged inverse micelles is measured in thin in-plane devices upon application of a voltage step. For the modelling of the transient dynamics of charged inverse micelles without chemical reactions or convection a 1-dimensional approximation of the Poisson–Nernst–Planck (PNP) equations is developed. This approximation is valid for a sufficiently thin in-plane device and allows much faster calculations. Firstly, it is verified in the case of a sufficiently thin in-plane device and high applied voltage that the 1-dimensional approximation is in good agreement with the solution of the full 2-dimensional PNP equations with finite elements implementation. Then, the 1-dimensional approximation is used to study the transient current and trajectories of trace amounts of charged colloidal particles in different regimes depending on the screening of the electric field. Also a comparison is made to the well-studied case of out-of-plane electrophoresis. Finally, it is verified that for voltages much larger than the thermal voltage the experimental results are in good agreement with the 1-dimensional approximation, indicating that the charge transport dynamics of charged inverse micelles in the bulk are described well by the model. [Copyright &y& Elsevier]

Explosion is a significant threat to chemical process safety, which often occurs suddenly with a wide range of impact, resulting in catastrophic disasters. Predictions of explosion hazards are required for regional safety assessment and disaster resilience enhancement of chemical industrial parks (CIPs). This paper, therefore, aims to develop a conceptual framework for systematically analyzing explosion evolutions and quantifying the potential hazards by combining system-theoretic process analysis (STPA) method with numerical simulation. The proposed framework consists of 5 steps: (i) establishment of hierarchical safe control structures (SCSs) of important chemical processing zones in the CIP, (ii) computational fluid dynamics (CFD) modeling for potential explosion evolutions in each zone by changing the examined parameters randomly, (iii) development of a convolutional neural network (CNN) prediction model through constant self-learning of CFD pressure field data, (iv) comprehensive assessment of blast damage by incorporating the outputs of the above numerical models into existing evaluation methods, (v) identification of unsafety control actions and causes, and safety constraints for the improvement of SCSs. Provided with monitoring data, the developed analysis architecture can predict explosion process hazards and recommend appropriate safety strategies in real time. This would service the multi-level requirements for explosion prevention and protection, supporting better-informed decision-making. The paper describes the concepts and implementation process of the method as a first step. [ABSTRACT FROM AUTHOR]

The benefits of integrated design using the Model Based System Engineering (MBSE) approach in the design process of mechatronic systems have gradually become apparent. The automatic generation of simulation models and geometric models based on System Modeling Languages (SysML) models enables system engineers to swiftly analyze and simulate system performance, visually depict design outcomes, and expedite the product development process. Due to the current system modeling's lack of model integration and geometric design functions, this paper proposes an integrated design and simulation method for mechatronic systems that can carry out complete model synchronization and verification, rapid geometric solution generation, and visual representation. Furthermore, a corresponding model synchronization integration framework is established. This framework primarily encompasses system de-sign, system simulation, and geometric design, with its model integration method being model transformation and model synchronization. The paper concludes with an example of the design process of a quadruped robot to validate the framework and its supported methods, providing a reference for other system design and integration endeavors. [ABSTRACT FROM AUTHOR]

Miniature ion trap mass spectrometer enables mass-to-charge ratio analysis of ions via quadrupole field in a low vacuum environment. It plays an important role in on-site detection due to its portability and specificity. In order to gain a deeper understanding of the analysis mechanism of miniature ion trap mass spectrometers, a quadrupole MS ion trajectory numerical simulation model (QITNS) is established in this paper for ions trajectory calculation under the action of quadrupole field, exciting field and neutral gas molecule collision. Compared with the existing methods, the model in this paper is simpler and more direct, which effectively explored the effects of dipole excitation and quadrupole excitation on ion manipulation under high background pressure. The simulation results demonstrate that high RF amplitude, low auxiliary AC amplitude and quadrupole excitation can effectively improve the isolation resolution. Besides, it clarified the difference between the analysis mechanism of ion trap mass spectrometers under high background pressure (above 13.332 Pa) and absolute vacuum conditions. The relevant results are consistent with the conclusions of previous experiments and other theories, proving the applicability and accuracy of the proposed calculation model and solution method. This research bears the guiding significance for further understanding the mechanism of quadrupole mass spectrometry as well as designing and developing miniature mass spectrometers. [Display omitted] • A simple numerical model is proposed for quadrupole mass spectrometry by directly coupling resonance and attenuation terms. • The model can elucidate the key factors for improving the resolution of the ion trap mass spectrometer. • It can also elucidate the ion manipulation rules under high background pressure conditions for miniaturized ion trap. [ABSTRACT FROM AUTHOR]

Promoting the development of green innovation is crucial for achieving the green transformation of society. This paper considers the decision bias of different agents in policy implementation and presents a theoretical model that captures the structure of the green innovation system. The model includes six subsystems: government, technology, public, energy, environment, and population. The study examines the transmission effect of green innovation and the influence mechanism of multiple decision biases on policy combination effects using a combination of various policy tools. The results show that: Various policy tools and their implementation differences have distinct effects on the green innovation and environmental performance. In most cases, the synergistic policy mix effect, surpassing the impact of individual policies, is driven by the resource effect. However, the synergistic effect of policy combination may not be fully realized, leading to potential conflicts. Due to various decision biases, particularly the gap in the public's green behavior, the policy mix faces challenges in achieving immediate synergistic effects. Combining tax policies with other policy instruments increases the risk of incoherence and inconsistency. However, in the long term, the combination of policy tools can exert strong late-developing advantages. This study provides insights for green innovation policy improvement. • This paper develops a green innovation system with the government subsystem serving as the operational hub. • This paper establishes a policy framework for green innovation systems based on multi-subject decision bias. • This paper simulates the impact of policy implementation on green innovation and main pollutant emissions. • The study finds that tax policy has a more significant dampening effect when combined with other policies. • This study finds that policy mix can exert resource effects, but decision biases cause a delayed manifestation. [ABSTRACT FROM AUTHOR]

Dynamic simulation is a powerful tool for accurately evaluating the thermal demands of buildings and assessing the impact of energy refurbishment actions on their final consumption. Conversely, semi-stationary models are widely adopted in commercial applications for its simplified approach, which reduce calculation times, resulting in standardized results showing a certain deviation with respect to the real energy This paper presents the energy and economic comparison between the dynamic simulation and semi-stationary approaches for the calculation of primary energy demand of residential buildings. The semi-stationary method, used by the legislation to calculate the buildings energy label, is based on an energy performance parameter, not representative of the real energy demand. Conversely, an approach based on dynamic simulation provides a more reliable estimation of the primary energy demand. The main novelty of this paper is to numerically prove that the energy and economic savings calculated by means of software based on the current legislation may be overestimated. In this work, the dynamic simulation of the building-plant system is performed by TRaNsient SYstem Simulation (TRNSYS) program. Each building apartment is divided in thermal zones, where the internal heat gains are defined in detail. The semi-stationary simulation of the building-plant system is performed according to the Italian standard UNI TS 11300. The models allow one to evaluate the yearly primary energy demand, along with the energy bill and CO 2 emissions. A specific case study is developed for a residential building located in Naples (Italy). The models are used to calculate the building energy demand for several scenarios, considering different thermal transmittances of the building elements. The results show that the semi-stationary method overestimates of primary energy saving, equal to 64.7 %, with respect to the one calculated with the dynamic approach, equal to 43.2 %. • Semi-stationary and dynamic simulations were compared for residential buildings. • Critical evaluation of energy and economic savings due to the building refurbishment. • Primary energy savings of 65 % and 43 % by semi-stationary and dynamic simulation. • Dynamic simulation is needed within the legal frame of energy efficient buildings. [ABSTRACT FROM AUTHOR]

This paper describes an accurate model of the Electrical Power Subsystem (EPS) of the Thermal Analysis Support and Environment Characterization Laboratory (TASEC-Lab), a university experiment developed for using in high-altitude balloon missions to measure and analyze the convection heat transfer. A Li-ion battery and two high efficient DC–DC converters have been characterized through laboratory tests and fitting to the experimental results. The developed mathematical models described in this paper are used to carry out accurate EPS simulations and are validated by comparison with the experimental data. • Design and modeling of the electrical power subsystem of a stratospheric balloon experiment. • New Li-lion battery discharging model that describes the three main parts: initial decay, linear, and exponential decay. • Formulation of a new DC/DC converter efficiency model. • Simulation and model validation of the electrical power subsystem. [ABSTRACT FROM AUTHOR]

Torsional nano-scanners have a variety of applications in nano/micro-electro-mechanical systems. In this paper, two- and three-dimensional numerical solutions based on the lattice Boltzmann are proposed for simulating the dynamic behavior of an electromechanical torsional nano-scanner. The complete governing equations are modified based on the couple stress theory and developed by considering the effect of the Casimir force. Furthermore, the physics of the system is extended by considering the effects of dissolved electric agents on the dynamic performance of the nano-scanner. The passive/active electrolyte flow behavior with the moving solid boundary is described and simulated using Nernst-Plank-Poisson compensation of the electrolyte flow. The proposed numerical results are validated by comparing them with those available in the literature. Finally, the influence of scale dependency and Casimir force on the nano-scanner's dynamic performance and pull-in instability are investigated. Also, as torsional nano-scanners might be immersed in ionic media, the impact of ionic concentration on the pull-in voltage of a nano-scanner is investigated. The obtained results demonstrate that increasing the ionic concentration reduces the instability voltage of the nano-scanner considerably. [ABSTRACT FROM AUTHOR]

Solar-hydrogen energy systems for spacecraft reliably provide energy for carrying out various kinds of unscheduled work on board and for eliminating emergency situations. Surplus energy is constantly accumulated on board in the form of the chemical energy of cryogenic hydrogen. The article presents too the result of the development of a solar-hydrogen power supply system for spacecraft, the onboard network of which provides slow and fast processes. The paper presents too pulsed and continuous models of voltage converters of the electrical power system of automatic spacecraft. It is proved on the simulation basis that the deviation of frequency characteristics of continuous models from pulse ones is insignificant (not more than 2%), while the use of continuous models to study both frequency and time characteristics of the converter allows us to reduce the simulation time tenfold. [ABSTRACT FROM AUTHOR]

In this paper, a fractional nonlinear control strategy based on the nested saturations technique and the Caputo-Fabrizio derivative for a quadrotor aircraft, to maintain desired position and orientation in stationary flight and trajectory tracking tasks, is proposed and developed. In addition, the dynamic model is obtained by using the Euler–Lagrange formulation, and then it is generalized to an arbitrary order through the Caputo-Fabrizio derivative. The traditional nonlinear control based on the nested saturation technique is also developed and implemented on the quadrotor for comparison purposes between both control schemes. Numerical simulations demonstrated the superiority of the proposed control strategy for stabilizing the quadrotor at hover and reaching the desired position and orientation, over its integer-order counterpart. In addition, three additional desired trajectories are considered, keeping the same gains and orders, to demonstrate the robustness of the proposed control scheme under different operating conditions. In this sense, our controller presents significant performance improvements, which were validated through system simulations. Our proposed control system and its traditional counterpart were tuned experimentally using the response of the system to a desired trajectory. [ABSTRACT FROM AUTHOR]

The interbank lending network, while facilitating transactions, poses risk contagion in the banking system. To address challenges in existing research, this paper models the interbank lending network using a multi-agent approach and generates a dynamic network through a bidirectional matching mechanism(BiMM). Additionally, We divide banks into three categories based on realistic bank balance sheet data. Given the fact that banks of different categories exhibit different degrees of contagion, we propose the weighted DebtRank (W-DebtRank). Then, comprehensive simulation analysis is conducted on the risk contagion of heterogeneous banks in the dynamic network using W-DebtRank. The proposed method addresses four issues: the heterogeneity of banks, the dynamic nature of networks, the practicality of lending strategies, and the comprehensiveness of risk analysis. The model is validated using the SRISK metric and the Monte Carlo-based SYMBOL simulation model. Through multiple perspectives in simulation experiments, the risk contagion process among banks is deeply investigated in our paper. [ABSTRACT FROM AUTHOR]

Harmonic power flow simulation is the main method to deduce and evaluate the steady-state harmonic content of urban rail flexible traction power supply system (FTPSS). The AC power quality of FTPSS can be optimized by conducting harmonic power flow simulation. However, traditional modeling and simulation methods are inefficient, so that it is difficult to achieve the real-time and accurate deduction of the harmonic power flow. Therefore, a high precision real-time simulation method of harmonic power flow based on multi-layer perceptron (MLP) is proposed in this paper. Firstly, the harmonic model of fully controlled converter is established by adopting MLP, which reduces the complexity of the model and improves the efficiency of harmonic calculation. Subsequently, the high precision data samples are used for the regression training of MLP model to ensure the accuracy of harmonic calculation. Moreover, the high precision real-time simulation of harmonic power flow is realized through the synchronous and interactive solution of MLP model and power flow model. Finally, theoretical analysis and simulation are conducted. The results demonstrate that the steady-state harmonic calculation time of the MLP model is significantly reduced to merely 1.02% of the traditional mechanism model's duration, which enables the harmonic power flow simulation to be effectively integrated into real-time system applications. In addition, the RMSE of the MLP model is only 0.0147, indicating the accuracy of the real-time simulation. The method proposed in this paper can quickly and precisely calculate the harmonic power flow, which is of practical value for harmonic evaluation and optimization of FTPSS. [ABSTRACT FROM AUTHOR]

This paper presents a method to automatically improve simulation model accuracy by using a stochastic gradient descent algorithm. The proposed algorithm updates models' parameters based on data collected from the actual domain under investigation. Collected data and feedback are fed into the simulation model to get predictions. In a linear prediction model, this data, along with the predictions, would form a typical regression problem; however, the stochastic gradient descent algorithm was modified to update the simulation model parameters. A tunneling case study is presented here, and the results show that the proposed algorithm can decrease simulation error by more than 50%, even in the case of incomplete simulation models or a missing inter-relationship between elements. Besides improving initial models, this paper provides a new approach for achieving data-driven simulation models that are updated in real time based on feedback from the actual domain. • Proposing a data-driven approach to enhance simulation performance. • Using stochastic gradient descent algorithm to update simulation parameters. • Deriving mathematical model to calculate error rate from a simulation model. • Applying the proposed method in a real case study of a tunneling project. • Suggesting a new approach for fitting data to model a simulation. [ABSTRACT FROM AUTHOR]

• Two coupled parallel frameworks for shell and tube heat exchangers are proposed. • Fully three-dimensional parallel computation on both sides of the heat exchanger is realized. • One-to-one method achieves 85% parallel efficiency in 14 cores computation. • One-to-many method improves computational efficiency by about 20 times over serial in 28 cores computation. Shell and tube heat exchanger is widely used as a common type of heat exchanger. When the size and the number of heat exchanger tubes are enormous, it is difficult to use the direct modeling method for numerical simulation of heat exchangers. The simplified modeling method based on porous media utilizing user-defined function (UDF) has been widely applied. However, when the three-dimensional (3D) modeling is required on the tube side, the parallelization problem still restricts the computational efficiency of numerical simulation. In this paper, a one-to-one parallel method was first developed to solve the problem of coupled parameter transfer between the primary and secondary sides in the parallel framework, which was tested to achieve a parallel efficiency of 85% under 14 cores. However, the method acquires complicated data transfer between nodes, large memory occupation, and the modeling of the tube side is different from the actual structure under certain circumstances. To solve the problems, a one-to-many parallel method is proposed, and the computational efficiency is tested to be enhanced by about 20 times under 28 cores compared with single core, with a parallel efficiency of 70%. The two methods proposed in this paper are of great significance to the parallel transformation of the future 3D full-size code for shell and tube heat exchangers development and the calculation efficiency improvement. [ABSTRACT FROM AUTHOR]

The paper provides an overview of the radiation protection challenges and the advanced simulation techniques used to study and plan complex interventions in radiation areas at CERN, particularly with regard to the Large Hadron Collider. The operational radiation protection aspects are supported by state of the art simulations by means of the FLUKA Monte Carlo code and estimates obtained via several tools, used within the CERN Radiation Protection group, such as ActiWiz, SESAME, and the Fluence Conversion Coefficients (FCC) method which extend the built-in FLUKA capabilities. The paper covers the general Radiation Protection principles and rules in force at CERN, the simulation tools/techniques used to fulfill operational tasks and predictive studies, and a set of case studies covering relevant applications at the Large Hadron Collider machine and experiments. • Advanced and reliable simulation tools are essential in modern Radiation Protection. • FLUKA is widely used at CERN for radiation protection studies at the LHC complex. • Simulation tools such as SESAME, FCC and ActiWiz extend FLUKA built-in capabilities. • RP studies of the upgrade of the LHC are mainly based on advanced simulation tools. • Real-case applications and examples are provided in the paper. [ABSTRACT FROM AUTHOR]

A system of diffusion–reaction equations coupled with a dissolution–precipitation model is discussed in this paper. We start by introducing a microscale model together with its homogenized version. In the present paper, we first derive the corrector results to justify the obtained theoretical results. Furthermore, we perform the numerical simulations to compare the outcome of the effective (homogenized) model with the original heterogeneous microscale model. [ABSTRACT FROM AUTHOR]

• A detailed dynamic simulation model for a Molten Salt Solar Tower system is implemented in Modelica®. • A two-phase flow model is developed for filling and drainage simulations of a molten salt receiver system. • In a discretized absorber tube model maximum values of local fluid and tube wall temperatures are approximated. • Startup and shutdown simulation including the entirely controlled receiver system are conducted. • Validation with CFD simulation is carried out. In order to realistically predict and optimize the actual performance of a concentrating solar power (CSP) plant sophisticated simulation models and methods are required. This paper presents a detailed dynamic simulation model for a Molten Salt Solar Tower (MST) system, which is capable of simulating transient operation including detailed startup and shutdown procedures including drainage and refill. For appropriate representation of the transient behavior of the receiver as well as replication of local bulk and surface temperatures a discretized receiver model based on a novel homogeneous two-phase (2P) flow modelling approach is implemented in Modelica Dymola®. This allows for reasonable representation of the very different hydraulic and thermal properties of molten salt versus air as well as the transition between both. This dynamic 2P receiver model is embedded in a comprehensive one-dimensional model of a commercial scale MST system and coupled with a transient receiver flux density distribution from raytracing based heliostat field simulation. This enables for detailed process prediction with reasonable computational effort, while providing data such as local salt film and wall temperatures, realistic control behavior as well as net performance of the overall system. Besides a model description, this paper presents some results of a validation as well as the simulation of a complete startup procedure. Finally, a study on numerical simulation performance and grid dependencies is presented and discussed. [ABSTRACT FROM AUTHOR]

Assembly accuracy analysis plays a very important role in verifying whether the design scheme of geometric accuracy in the product design stage can meet the functional requirements of mechanical product. Form deviations, position and orientation deviation are inevitable in manufactured parts, and must be considered during assembly accuracy analysis. With regard to the representation of form deviations, it is verified that skin model shapes are effective. However, the existing simulation approaches of skin model shapes for cylindrical parts are mainly based on gaussian random field, without considering the spatial distribution characteristics of form deviations in dealing with the relationship between geometrical and dimensional deviation for cylindrical parts. Especially, when considering local surface deformations of cylindrical mating surfaces generated during the assembly process, the form deviations with different distribution characteristics leads to different contact deformation, which may have further influence on assembly accuracy analysis of cylindrical parts. To address above problems, this paper proposes a simulation method of skin model shapes of cylindrical parts based on Non-Gaussian random field considering the spatial distribution characteristics of form deviations, and the local surface deformations are analyzed with a boundary element method. Based on above, the relative positioning deviation of cylindrical mating surfaces is obtained considering the influence of form deviations and local surface deformations. Finally, the effectiveness of the proposed method is verified with case studies. Specifically, the results of case study reveal that the influences of form deviations considering spatial distribution characteristics and local surface deformations cannot be ignored for assembly accuracy analysis of cylindrical parts. In addition, for the relative positioning deviation of cylindrical mating surfaces for loose fit, the influence of local surface deformations on translational deviations along the x-axis and y-axis is greater than that on rotational deviations around the x-axis and y-axis. • A skin modeling method of cylindrical parts is proposed based on Non-Gaussian random field. • Spatial distribution characteristics of form deviations and local surface deformations are considered. • CG-DC-FFT method is adopted to solve local surface deformations of cylindrical mating surfaces. • Form deviations of cylindrical mating surfaces have influence on assembly accuracy analysis. • Local surface deformations of cylindrical mating surfaces have influence on assembly accuracy analysis. [ABSTRACT FROM AUTHOR]

Photovoltaic (PV) systems have become an integral and widespread part of renewable energy generation. In combination with energy storage, they offer a variety of advantages such as increased self-sufficiency or improved grid stability. However, geographic location, subsidies, energy tariffs, size of PV panels and battery, and other factors significantly influence the overall performance and profitability of the system. Solving this complex task of system design and component dimensioning is not easy. The diversity and multitude of parameters therefore usually requires the help of, more or less complex, computer simulations. This led and still leads to a high publication activity on techno-economic and other optimizations for such systems. However, the operating strategies and component models are often oversimplified, leading to results with significant errors. The goal of this paper is to provide in-depth insight into component modeling and parametrization for PV module, battery energy storage, and inverter, as well as giving suggestions on appropriate control strategies. The focus lies on the description of suitable simple-but-accurate models and their parametrization. In order to avoid the effort of having to conduct measurements for component characterization, an approach relying on values presented in product data sheets is considered. Furthermore, the effects of model simplifications, as they are found in many publications, are shown. Finally, the importance of an uncertainty analysis for the entire simulation is discussed in order to gain insight into the accuracy of the calculated simulation results and their dependency on model- and input-parameters. • Photovoltaic system modeling/simulation. • Component modeling for PV module, battery energy storage and inverter. • Suitable simple-but-accurate models and their parametrization • Characterization relying on product data sheets with minimal informations. [ABSTRACT FROM AUTHOR]