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Using the RANS approach with the standard k-ω turbulence model, this study offers a novel investigation into the dynamic and thermal properties of turbulent impinging jet arrays. Our study examines the combined effect of the number of jets (N) and the jet–jet spacing (S) on flow mechanisms and heat transfer performance, which is unique compared to previous research that frequently focuses on the individual effects of parameters. Through the investigation of the turbulent kinetic energy, friction coefficient, velocity contours, streamlines, pressure contours, and local and mean Nusselt numbers, we provide important information about how these parameters impact flow dynamics. Local heat transfer in the central and lateral zones is greatly improved by increasing the number of jets (N) and the jet–jet spacing (S), according to our findings. When the jet–jet spacing (S) is increased from 1 to 4, the maximum value of the Nusselt number along the central zone improves by 21.2%. Furthermore, the best improvement in the maximum Nusselt number (24.5%) along the lateral zone is obtained by increasing the number of jets (N) from 5 to 11 for the lower value of jet–jet spacing S = 1. It has also been noted that lower jet-plate distance (H), lower jet–jet spacing (S), and a higher number of jets (N) result in better average heat transfer. To predict the average Nusselt number based on three parameters (N, S, and H), we establish a critical correlation, which provides a useful tool for optimizing impinging jet configurations in a variety of engineering applications. The diversification of the parameters studied and the thorough analysis in this study add important new results to the field by demonstrating the significant effects of the number of jets, jet–jet spacing, and jet-plate distance on the thermal and dynamic behavior of impinging jet arrays. [ABSTRACT FROM AUTHOR]

Implementing deep learning-based surrogate reservoir models (SRMs) on an operational field scale and replacing them with numerical industrial simulators has yet hindered challenges in acquiring high-quality and fast-supply data for both the initial training and ongoing usage phases of SRM. These data challenges make conventional SRMs inefficient for field-scale reservoirs due to their dependence on time-consuming finite difference (FD) data. This research introduces a new generation of well-based intelligent models that tackle the challenges posed by conventional methods by integrating dynamic data from StreamLines (SL) as a reliable and fast-supply data source. SL data is utilized for the first time in developing a well-based SRM, which accelerates the data supply process and enhances the model's efficiency during simulation. The swift accessibility of SL data enables the use of a direct training strategy in the LSTM network, effectively mitigating typical training error accumulation. By introducing a new Streamline-based data sampling technique, data continuity and quality were vastly enhanced, resulting in higher accuracy of models with lower data requirements during the training phase and faster convergence. Additionally, leveraging SL data, the introduced database allows the intelligent models to operate independently from FD data during the ongoing usage phase. This independence eliminates the time load of finite difference data provision in conventional SRMs, greatly enhancing its functionality. This breakthrough in developing well-based SRMs offers improved data acquisition, simulation efficiency, and facilitates real-time decision-making in dynamic reservoir simulation applications. Promising results are achieved in predicting well oil/water production rates, with an average absolute relative deviation of less than 4% for two heterogeneous benchmark reservoir models. Furthermore, the simulation run time and overall process duration are significantly reduced compared to high-fidelity FD simulators and conventional proxy models. [ABSTRACT FROM AUTHOR]

Eight-node quadrilateral isoparametric elements of the serendipity type have frequently been used in finite-element analyses of two-dimensional seepage problems. The shape functions for these elements are quadratic. Hence, nonlinear variation in the potential and stream function values across each element could be approximated to a high degree of accuracy. This also necessitates a commensurate high-order interpolation function to locate, in a straightforward way, equipotential lines and streamlines. In this paper, a quadratic interpolation algorithm for locating deformation contours is modified to suit flow net generation. The modification lies in the procedure for identifying the pairs of the points of intersection to be joined when there are four, six, or eight points of intersection of the contour segments of the same level and the edges of an element. The original algorithm finds the pairs of intersection points in a local coordinate system by testing all possible cases that may be encountered. The modified algorithm considers that in most, if not all, scenarios, equipotential lines and streamlines extend monotonically from one impervious boundary of the flow domain to another and from an inflow boundary to an outflow boundary, respectively. The intersection points are rapidly paired by converting their local coordinates to global coordinates and sorting the order of the intersection points according to their global coordinates. The modified algorithm eliminates the need for an exhaustive search and complex matching process, enhancing computational efficiency. The modified algorithm is verified against an exact analytical solution to the flow net for a levee under-seepage flow. Excellent agreement is obtained. Two additional illustrative examples are analyzed. One is unconfined seepage through a rectangular dam, and the other is confined seepage beneath unsymmetrical cofferdams. The equipotential lines and streamlines obtained from the modified algorithm are shown to be smoother and more accurate than those obtained using popular commercial software (GeoStudio 24.2.0), especially when a coarse finite-element mesh is adopted. [ABSTRACT FROM AUTHOR]

This study searches for an effective cross-sectional shape of grooves by evaluating their trapping effect using numerical methods. Grooves are widely employed to enhance lubrication performance across various systems, including in bearings and valves, where they serve multiple functions, such as improving load-carrying capacity, addressing pressure imbalances, storing lubricant, and minimizing leakage. Beyond these roles, grooves are crucial in preventing three-body abrasive wear by capturing solid particles, such as wear debris, within the system. This study specifically focuses on the trapping effect of grooves, examining how variations in their cross-sectional shape and the Reynolds number of the lubricant used influence this effect. To evaluate the groove's trapping capability, the study analyzed particle trajectories and streamlines within the groove, as well as the number of particles effectively trapped. The results indicate that grooves with certain cross-sectional shapes, particularly those generating multiple vortices and small eddy currents, demonstrate superior trapping effectiveness. These findings contribute to the design of more efficient grooves in lubrication systems, providing insights into how groove geometry can be optimized to enhance the performance and longevity of mechanical components by mitigating wear through effective particle entrapment. This research has potential applications in the design and improvement of lubrication systems where managing wear and enhancing efficiency are critical concerns. [ABSTRACT FROM AUTHOR]

Appropriate mesh refinement plays a vital role in the accuracy and convergence of computational fluid dynamics solvers. This work is an extension of the previous work that further demonstrates the accuracy of the 3D adaptive mesh refinement method by comparing the accuracy measures between the ones derived from the analytical fields and those identified by the refined meshes. The adaptive mesh refinement method presented in this study is based on the law of mass conservation for three-dimensional incompressible or compressible steady fluid flows. The assessment of the performance of the adaptive mesh refinement method considers its key features such as drawing closed streamline and identification of singular points, asymptotic planes, and vortex axis. Several illustrative examples of the applications of the 3D mesh refinement method with a multi-level refinement confirm the accuracy and efficiency of the proposed method. Furthermore, the results demonstrate that the adaptive mesh refinement method can provide accurate and reliable qualitative measures of 3D computational fluid dynamics problems. [ABSTRACT FROM AUTHOR]

This study reports both MagnetoHydroDynamics (MHD) and heat generation aspects of a water-based hybrid nanofluid flow with various shapes of the nanoparticles involving Nimonic 80A and Fe 3 O 4 , over a moving wedge. Similarity transformations were adapted to obtain non-dimensional equations and solved using MATLAB bvp4c code. All the results and graphs were formulated after a positive outcome of our results with that available in existing literature. Nusselt number, which signifies the heat transfer rate in a flow, increased with an increase in empirical shape factors of the nanoparticle with a contrasting decrease in the drag experienced during the flow, represented by the skin friction coefficient. The velocity profile decreased at a rate of 0.75% for M = 0. 6 to M = 0. 8 due to the augmenting Lorentz forces while it augmented by 18.9% for an augmenting velocity ratio parameter from R = 0. 0 to R = 0. 5 due to the no-slip boundary conditions. Both the Nusselt number and skin friction coefficients decreased with an increase in magnetic parameter. An increase in the nanoparticle concentration resulted in an incrementing streamline value along with increasing temperature profile due to increasing thermal conductivity of the fluid flow system. The physical significance of the study involves in its applications in nuclear, steel industries, MRI scanning for its anti-corrosive and high thermal conductivity properties. [ABSTRACT FROM AUTHOR]

Rotary mills aim to effectively reduce the size of particles through a process called comminution. Modelling comminution in rotary mills is a challenging task due to substantial material deformation and the intricate interplay of particle kinematics of segregation, mixing, crushing, and abrasion. Existing particle-based simulations tend to provide predictions that cannot cope with the large number of particles within rotary mills, their wide range of sizes, and the physics dictating the crushing of individual particles. Similarly, there is currently no deterministic modelling means to determine the evolving population of particle sizes at any point in time and space within the mill. The aim of this two-part contribution is to address these gaps by advancing a framework for a novel stochastic comminution model for rotary mills, which has a well-defined deterministic continuum limit and can cope with arbitrarily large numbers of particles. This work describes the basic physics and structure of the new model within a heterarchical framework for ball and autogenous grinding mills. The primary focus of this Part I paper is to develop a computational model for the integration of motion of material along streamlines inside a mill. Coupled to this process is the kinetic physics dictating particle crushing. In a subsequent work, Part II, segregation and mixing will be added to this model such that realistic behaviour from the mill can be observed. [ABSTRACT FROM AUTHOR]

In this study, the effects of suction and buoyancy are used to analyze the Ternary hybrid nanofluid flow on a stretching sheet through a porous media. Ternary hybrid nanofluid is (Carbon nanotubes) CNT + Graphene + Al 2 O 3 with base fluid as Water. Case-1 Buoyancy Assisting flow and Case-2 Buoyancy Opposing flow. Hybrid nanofluids have been used to speed up the heat transfer process. Nonlinear partial differential equations (PDEs) have been converted to ordinary differential equations (ODEs) using Lie group transformations. The ODE45, an algorithmic approach, has been using the aid of this built-in solver, and the resulting Ordinary differential equations were resolved. The general relationship between temperature, velocity, heat transfer rate, and shear stress on a stretchy surface is shown for a range of values of the significant factors. The temperature profiles have been rising with the impact of Da , f w . Using streamlines to examine the flow pattern of a fluid and a method of machine learning, in terms of modern language, an artificial neural network (ANN) made up of artificial neurons or nodes is known as a neural network. A neural network is a network or circuit of genetic neurons. [ABSTRACT FROM AUTHOR]

Particle tracking is a common post processing method in groundwater hydrology. In this paper we describe Ichnos, a particle tracking code able to work with flow simulations obtained from either finite difference, finite element, adaptive mesh, or mesh free methods. Ichnos can trace virtual particles (streamlines) in flow fields of any fluid dynamics context, but its application is here focused on groundwater-based flow fields. The code is written in C++ and the structure of the code allows for it to be easily extended. In this study we describe the main features of the code and present several illustrations.

In the present work, the impact of periodic body acceleration on the unsteady flow of blood in an inclined artery has been investigated. The blood is represented by an incompressible, viscous, non-Newtonian Jeffrey fluid. The artery is assumed to have mild overlapping stenoses inside its lumen. The perturbation method is used to solve the governing nonlinear coupled partial differential equations. Here, the Womersley frequency parameter is considered small enough for blood flow through arteries. Analytic expressions for the wall shear stress, stress at the critical height of stenosis, velocity profile, volumetric flow rate, pressure drop, resistive impedance, and effective viscosity are obtained using the perturbation technique. Regarding different flow parameters, the effects of body acceleration, pulsatility, the non-Newtonian character of blood, and velocity slip are examined and graphically depicted. It is concluded from the present analysis that the flow impedance rises when the stenosis reaches its critical height, but it falls as the velocity slip at the wall increases. It is also observed that when body acceleration increases, flow rate, velocity, and shear stress near the critical height of stenosis all rise, whereas wall shear stress decreases as body acceleration rises. Here, we also analyzed the flow pattern of the non-Newtonian Jeffrey fluid when it passes through the overlapped stenosed artery with the help of streamlines. The results of the present problem have been verified with the previous existing results in the literature. [ABSTRACT FROM AUTHOR]

Understanding the flow instabilities encountered by the turbocharger compressor is an important step toward improving its overall design for performance and efficiency. While an experimental study using Particle Image Velocimetry was previously conducted to examine the flow field at the inlet of the turbocharger compressor, the present work complements that effort by analyzing the flow structures leading to stall instability within the same impeller. Experimentally validated three-dimensional computational fluid dynamics predictions are carried out at three discrete mass flow rates, including 77 g/s (stable, maximum flow condition), 57 g/s (near peak efficiency), and 30 g/s (with strong reverse flow from the impeller) at a fixed rotational speed of 80,000 rpm. Large stationary stall cells were observed deep within the impeller at 30 g/s, occupying a significant portion of the blade passage near the shroud between the suction surface of the main blades and the pressure surface of the splitter blades. These stall cells are mainly created when a substantial portion of the inlet core flow is unable to follow the impeller's axial to radial bend against the adverse pressure gradient and becomes entrained by the reverse flow and the tip leakage flow, giving rise to a region of low-momentum fluid in its wake. This phenomenon was observed to a lesser extent at 57 g/s and was completely absent at 77 g/s. On the other hand, the inducer rotating stall was found to be most dominant at 57 g/s. The entrainment of the tip leakage flow by the core flow moving into the impeller, leading to the generation of an unstable, wavy shear layer at the inducer plane, was instrumental in the generation of rotating stall. The present analyses provide a detailed characterization of both stationary and rotating stall cells and demonstrate the physics behind their formation, as well as their effect on compressor efficiency. The study also characterizes the entropy generation within the impeller under different operating conditions. While at 77 g/s, the entropy generation is mostly concentrated near the shroud of the impeller with the core flow being almost isentropic, at 30 g/s, there is a significant increase in the area within the blade passage that shows elevated entropy production. The tip leakage flow, its interaction with the blades and the core forward flow, and the reverse flow within the impeller are found to be the major sources of irreversibilities. [ABSTRACT FROM AUTHOR]

A numerical simulation of an incompressible, unsteady, laminar shear flow past a circular cylinder with an attached arc-shaped plate using higher order compact scheme is presented in this work. The timing accuracy of the scheme is second order, and its spatial accuracy is at least third order. The method calculates time-marching steady-state and unsteady flow very effectively for several different Reynolds values. Simulations are performed for Reynolds number (R e) = 115 , using the shear parameter values κ = 0.0 , 0.05 . The radius of the circular cylinder is R 0 and the radius of the circular arc is ( 1.5 ∗ R 0 ). In cylindrical polar coordinates, the Navier–Stokes (N–S) equations are taken as the governing equations in their streamfunction—vorticity form. From the perspectives of stream function, vorticity contours, lift coefficient, and phase diagrams, we look at how the shear rate affects the process of vortex shedding. We have observed that the shear rate have a substantial impact on the evolution of the wake behind the cylinder and the phenomenon of vortex shedding. When comparing shear flow ( κ = 0.05 ) to uniform flow ( κ = 0.0 ), we noted significant differences in the vortex shedding behavior. In the case of uniform flow, the shedding is symmetric and occurs periodically, while shear flow leads to an asymmetric shedding pattern. In addition to demonstrating the impact of vortex shedding from the circular cylinder with an attached plate in shear flow, the numerical results also highlight numerous significant flow producing features with κ . To our knowledge, this is the first time a numerical investigation has been done to explore the vortex-shedding phenomena for a circular cylinder with an attached arc-shaped control plate. [ABSTRACT FROM AUTHOR]

Significance: The CuO, Al2O3, and TiO2 nanoparticles find extensive applications in advanced chemical reaction-based thermal transport and quadratic convective nanofluids due to their exceptional thermal properties and chemical stability. Increased thermal conductivity of these nanoparticles used to enhance heat transfer in various chemical reactors, resistance to chemical degradation and photocatalytic reactors and solar energy applications. Motive: This study brings the investigation about quadratic convection-based thermal transport to infinite shear rate for magnetized ternary radiative cross nanofluid with homogeneous-heterogeneous chemical reactions. Water is taken as base fluid and three nanoparticles are Copper oxide (CuO), aluminium oxide (Al2O3), and titanium dioxide (TiO2). Heat transport analysis is made through quadratic convection, magnetic field and thermal radiation. Concentration of nanofluid is scrutinized though homogeneous-heterogeneous chemical reactions. Method: ology: Physical problem with assumptions generates the system of partial differential equations (PDEs) and these PDEs are transformed into ordinary differential equations (ODEs) through similarity variables. Furthermore, a unique combination of Bvp4c and Levenberg Marquardt neural network (LM-NN) schemes is utilized to fetch the numerical solutions. Bvp4c is utilized to solve the governing equations, while LM-NN serves to enhance predictive capabilities and capture intricate nonlinear relationships. Findings: Magnetic environment, chemical process, radiations effects and volumetric fraction of nanoparticles make better heat transfer efficiency and control.

To analyze the waterflooding system of an oil reservoir and predict the effectiveness of geological and technical measures, information is required on the distribution of injection rate between the reacting production wells and the reservoir boundary. The most reliable methods for calculating these characteristics are methods based on hydrodynamic modeling of flow. Modern commercial software implement algorithms for these purposes based on the construction and analysis of streamlines. At the same time, there are no reliable estimates of the accuracy of these algorithms and recommendations for choosing the optimal parameters in the available literature.In this paper, we propose an algorithm for calculating the proportions of the distribution of the total well flow rate between the surrounding wells and the reservoir boundary using streamlines. Streamlines are constructed on the basis of a finite element solution to the flow problem averaged over the formation thickness and determine the boundaries of the streamtubes connecting the corresponding wells. The flow rate through the flow tubes is calculated by numerically integrating the Darcy velocity field of the indicated two-dimensional problem. The algorithm was tested on idealized examples of waterflooding elements of typical well placement schemes, when the exact distribution of the proportions of fluid injected into the formation is known, and on the example of comparison with the solution of the problem of simulating the injection of a tracer into the reservoir. Recommendations for the selection of starting points for tracing streamlines are presented, which allow achieving a minimum level of error in determining the mutual influence of wells in a wide range of the computational grid resolution of the flow model.A more general application of the described method without significant changes is to equip the high resolution flow model along fixed stream tubes with their rate characteristics.

This study searches for an effective cross-sectional shape of grooves by evaluating their trapping effect using numerical methods. Grooves are widely employed to enhance lubrication performance across various systems, including in bearings and valves, where they serve multiple functions, such as improving load-carrying capacity, addressing pressure imbalances, storing lubricant, and minimizing leakage. Beyond these roles, grooves are crucial in preventing three-body abrasive wear by capturing solid particles, such as wear debris, within the system. This study specifically focuses on the trapping effect of grooves, examining how variations in their cross-sectional shape and the Reynolds number of the lubricant used influence this effect. To evaluate the groove’s trapping capability, the study analyzed particle trajectories and streamlines within the groove, as well as the number of particles effectively trapped. The results indicate that grooves with certain cross-sectional shapes, particularly those generating multiple vortices and small eddy currents, demonstrate superior trapping effectiveness. These findings contribute to the design of more efficient grooves in lubrication systems, providing insights into how groove geometry can be optimized to enhance the performance and longevity of mechanical components by mitigating wear through effective particle entrapment. This research has potential applications in the design and improvement of lubrication systems where managing wear and enhancing efficiency are critical concerns.

Streamlines are a popular method of choice in many flow visualization techniques due to their simplicity and intuitiveness. This paper presents a novel streamline seeding method, which is tailored for visualizing unsteady flow in augmented reality (AR). Our method prioritizes visualizing the visible part of the flow field to enhance the flow representation's quality and reduce the computational cost. Being an image‐based method, it evenly samples 2D seeds from the screen space. Then, a ray is fired toward each 2D seed, and the on‐the‐ray point, which has the largest entropy, is selected. It is taken as the 3D seed for a streamline. By advecting such 3D seeds in the velocity field, which is continuously updated in real time, the unsteady flow is visualized more naturally, and the temporal coherence is achieved with no extra efforts. Our method is tested using an AR application for visualizing airflow from a virtual air conditioner. Comparison with the baseline methods shows that our method is suitable for visualizing unsteady flow in AR. [ABSTRACT FROM AUTHOR]

AbstractThis investigation delves into the peristaltic flow characteristics of a Newtonian fluid within a permeable channel, emphasizing the influence of nonlinear curvature and wall properties. The study employs wave trains of varying amplitudes and phases to induce an asymmetric configuration along the channel boundaries. The curvature effects are contingent upon the ratio of channel width to wavelength, and the accuracy of results is maintained up to the second order in δ. To facilitate the derivation of closed-form solutions at higher levels, a domain transformation is executed, converting a channel with a variable cross section into one with a uniform cross section. To impose constraints on parameters and achieve a singular flux in the presence of a specified pressure gradient, a distinctiveness criterion is formulated. This study investigates the interplay of inertia and curvature on pumping and trapping, examining both symmetric and asymmetric channels. The pressure difference escalates with wave number in both channel configurations. Moreover, in the absence of inertial forces and flux, the impact of curvature on the pressure difference demonstrates a direct proportionality. Conversely, an augmentation in the permeability of the porous channel correlates with a reduction in the pressure difference. An intriguing observation arises as phase differences increase: the visibility of the bolus diminishes, and the streamlines become more prominent. This establishes a favorable environment for fluid flow, enhancing our understanding of the intricate dynamics at play in peristaltic flow within permeable channels. [ABSTRACT FROM AUTHOR]

The present study presents a computational investigation into the thermal mixing along with entropy generation throughout the natural convection flow within an arbitrarily eccentric annulus. Salt water is filled inside the eccentric annulus, in which the outer and inner cylinders have T c and T h constant temperatures. The Boussinesq approximation is used to develop the governing equations for the natural convection flow, which are then solved on a structured quadrilateral mesh using the OpenFOAM software package (FOAM-Extend 4.0). The computational simulations are performed for Rayleigh numbers ( R a = 10 3 – 10 5 ), eccentricity ( ϵ = 0 , 0.4 , 0.8 ), angular positions ( φ = 0 ∘ , 45 ∘ , 90 ∘ ), and Prandtl number ( P r = 10 , salt water). The computational results are visualized in terms of streamlines, isotherms, and entropy generation caused by fluid friction and heat transfer. Additionally, a thorough examination of the variations in the average and local Nusselt numbers, circulation intensity with eccentricities, and angular positions is provided. The optimal state of heat transfer is shown to be influenced by the eccentricity, angular positions, uniform temperature sources, and Boussinesq state. Moreover, the rate of thermal mixing and the production of total entropy increase as R a increases. It is found that, compared to a concentric annulus, an eccentric annulus has a higher rate of thermal mixing and entropy generation. The findings show which configurations and types of eccentric annulus are ideal and could be used in any thermal processing activity where a salt fluid ( P r = 10 ) is involved. [ABSTRACT FROM AUTHOR]

The numerical simulation of free convection flow within a square-shaped enclosure for various orientations of elliptic blockage (EB) is performed in the present study. The bottom wall of the cavity remains uniformly heated, where the left and right (side) walls as well as the boundary wall of the elliptic blockage are insulated and the top wall remains at a cool temperature. As Pr remains constant, the effects of different values of Ra have a great influence on overall fluid flow and temperature gradient for three different locations: bottom elliptic blockage (BEB), center elliptic blockage (CEB) and top elliptic blockage (TEB), as a mass flow circulation has been identified, and a state of equilibrium has been established within the fluid flow simulations along with the isotherm contours. The outcomes of the numerical analysis are presented with the streamlines, isotherms, and variations of the average Nusselt number. [ABSTRACT FROM AUTHOR]

Fish protection is a priority in regions with ongoing and planned development of hydropower production, like the Mekong River system. The evaluation of the effects of turbine passage on the survival of migratory fish is a primary task for informing hydropower plant operators and authorities about the environmental performance of plant operations. The present work characterizes low pressures and collision rates through the Kaplan-type runners of the Xayaburi hydropower station. Both an experimental method based on the deployment of Sensor Fish and a numerical strategy based on flow and passage simulations were implemented on the analysis of two release elevations at one operating point. Nadir pressures and pressure drops through the runner were very sensitive to release elevation, but collision rates on the runner were not. The latter showed a frequency of occurrence of 8.2–9.3%. Measured magnitudes validated the corresponding simulation outcomes in regard to the averaged magnitudes as well as to the variability. Central to this study is that simulations were conducted based on current industry practices for designing turbines. Therefore, the reported agreement helps turbine engineers gain certainty about the prediction power of flow and trajectory simulations for fish passage assessments. This can accelerate the development of environmentally enhanced technology with minimum impact on natural resources. [ABSTRACT FROM AUTHOR]

Computer simulation of the metal flow pattern during the settlement of flat billets is considered on the basis of the developed "equi-theory" based on the principle of the shortest normal, which makes it possible to build a drawing of a multi-contour billet according to the specified dimensions, to determine the metal flow separating lines, streamlines, to analyze the metal flow pattern, and to substantiate the use of technological methods and structural elements that prevent or reduce the risk of defects. The general characteristics of broadly oriented, special and highly specialized software complexes are presented, their advantages and weaknesses are noted. The results of computer modeling of the metal flow pattern for complex multi-contour workpieces using the developed EQUI software package are shown. [ABSTRACT FROM AUTHOR]

In the present investigation, magnetohydrodynamic (MHD) micropolar fluid flow between a stationary disc and a rotating disc with a constant angular velocity is considered. The study investigates the effect of magnetic field and microrotation structure on the flow characteristics. The governing equations of motion are transformed to a system of nonlinear ordinary differential equations (ODEs) in dimensionless form using Von Karman's similarity transformations. An algorithm based on implicit finite difference method-Keller-box Scheme is employed to solve the resulting similarity equations for various pertinent parameters. Numerical solutions of velocity profiles, pressure gradient and microrotation profiles are discussed, and presented through tables and graphs for various Magnetic parameter. Comparisons are made between the obtained results and previously reported findings in the literature. The successful validation against existing literature supports the effectiveness of the methodology employed in this investigation. [ABSTRACT FROM AUTHOR]

An analytical study was carried out on an anchored circular pit with a submerged free surface in layered soil. The seepage field around the anchor circular pit was divided into three zones. Separate variable method was used to obtain the graded solution forms of head distribution in the column coordinate system for each of the three regions. Combined with the continuity condition between the regions the Bessel function orthogonality was used to obtain the explicit analytical solution of the seepage field in each region, and the infiltration line was determined. Comparison with the calculation results of Plaxis 2D 8.5 software verified the correctness of the analytical solution. Based on the analytical solution, the influence of the radius of the pit and the distance of the retaining wall from the top surface of the impermeable layer on the total head distribution on both sides of the retaining wall was analyzed. And the variation in the infiltration line was determined with the above parameters. The results show that as the pit radius, r, decreased, the total head on both sides of the retaining wall gradually increased, and the height of the submerged surface drop also increased. As the distance, a, between the retaining wall and the impermeable boundary at the bottom increased, the hydraulic head on the outer side of the retaining wall decreased and the head on the inner side increased. The height of the submerged surface drop increased with decreasing depth of insertion of the retaining wall. The depth of insertion of the retaining wall had a greater influence on the degree of diving surface drop than the pit radius. [ABSTRACT FROM AUTHOR]

The use of 4D seismic data in history matching has been a topic of great interest in the hydrocarbon industry as it can provide important information regarding changes in subsurfaces caused by fluid substitution and other factors where well data is not available. However, the high dimensionality and uncertainty associated with seismic data make its integration into the history-matching process a challenging task. Methods for adequate data reduction have been proposed in the past, but most address 4D information mismatch from a purely mathematical or image distance-based standpoint. In this study, we propose a quantitative and flow-based approach for integrating 4D seismic data into the history-matching process. By introducing a novel distance parametrization technique for measuring front mismatch information using streamlines, we address the problem from a flow-based standpoint; at the same time, we maintain the amount of necessary front data at a reduced and manageable amount. The proposed method is tested, and its results are compared on a synthetic case against another traditional method based on the Hausdorff distance. The effectiveness of the method is also demonstrated on a semi-synthetic model based on a real-case scenario, where the standard Hausdorff methodology could not be applied due to high data dimensionality. [ABSTRACT FROM AUTHOR]

An abdominal aortic aneurysm (AAA) is a localized dilatation of abdominal aorta. This study investigates a 2-dimensional unsteady and laminar flow through a bifurcated artery with an aneurysm that is computationally and mathematically simulated using 3-dimensional geometry. The fluid used in this simulation is blood which is Newtonian for high shear rate. The computational technique is used to solve the equations that governs due to the flow. The flow of blood is analyzed with the assist of cut planes of pressure and velocity in the abdominal aortic aneurysm (AAA) for t=1s and t=4s. The pressure on the wall and complete velocity profile are also displayed with the assist of graphs. The streamlines are also shown with the help of graphs for t=1s and t=4s. The results can be used in the treatment of abdominal aortic aneurysm.

The objective of this numerical study is to examine how different Reynolds numbers impact heat and mass transfer in an unsteady forced convective two-dimensional flow within a right-angle triangular cavity. The lowest surface of the enclosure is held at a fixed temperature and concentration, whereas the slanted surface is taken to be a cool surface. Furthermore, the cavity's left wall is adiabatically positioned to move in two directions: upwards (aiding flow) and downwards (opposing flow), with a constant speed being maintained. The partial differential equations that govern the system are converted into a non-dimensional form through a straightforward transformation. The finite-element scheme is employed to solve these dimensionless equations. The analysis facilitates the investigation of the belongings of the Reynolds number on the heat and mass transfer appearances by using streamlines, isotherms, and isoconcentration lines. It is initiated that the temperature spreading as well as concentration within the cavity depends strongly on the Reynolds number. Moreover, the motion of the moving wall influences the patterns of fluid flow, temperature, and concentration fields. This study provides a comprehensive investigation into heat and mass transfer behavior occurring within a lid-driven right-angled triangular cavity moving in two opposite directions for aiding flow and opposing flow respectively.

Subsurface "tile" drains are an important water management practice for many productive agricultural soils, but drains also deliver nitrate-nitrogen and other soluble chemicals from the bottom of the rootzone to surface ditches and streams. Many studies have focused on determining different ways to reduce the delivery of nitrate and other chemicals to subsurface drains while still providing adequate drainage for crop production. One important consideration in such studies that is often overlooked is the response time of drainage outflow to changes in management at the soil surface. Drains integrate flow from distances immediately adjacent to the drain all the way to the midplane between parallel drains, which means changes in management will not be fully reflected in drainage waters for months to several years, depending on the drainage intensity, soil characteristics, and precipitation. This bromide tracer study was conducted at the Southeast Purdue Agricultural Center (SEPAC) in Indiana, USA. Bromide tracer was applied at the beginning of the drainage season (November) at different distances from the drains on multiple plots of different drain spacings. The bromide concentration in the drainflow was monitored over the next five years to determine breakthrough curves and the amount of time required to flush the bromide from the system. The initial breakthrough of bromide occurred during the first appearance of drainage after application, regardless of the location of the bromide strip, suggesting some preferential flow was occurring. This was further investigated with comparison to curves of theoretical travel time following Kirkham's analytic solution for flow to a tile drain. The full transport of the bulk of the chemical took 2-3 years, but varied greatly among the different treatments, reflecting the longer travel times for locations further from the drain. [ABSTRACT FROM AUTHOR]

At present, due to the pandemic context, air transport is being re-analysed. Especially the economy class, where most passengers travel, having six people in a row of seats becomes risky because there is no minimum distance between people. If a person is infected, they can transmit the virus very easily, even if they wear a mask. The project also contains an assessment of the possibility of transmitting the virus through the cabin ventilation system. Two ventilation solutions are simulated in Ansys Fluent, both for the current cabin configuration of a one-aisle aircraft. Next, a solution that would improve the health safety on board is proposed. The new seats and cabin configurations are designed. Firstly, the middle seat replaced with a luggage storage box, large enough to carry some "hold" luggage and secondly, a plexiglass panel support, which can be mounted on the seat backside is conceived. Finally, the air flow in aircraft cabin for this new arrangement is analysed. [ABSTRACT FROM AUTHOR]

The oil and gas sector is important to the global economy because it covers the exploration, production, processing, transportation, and distribution of oil and natural gas resources. Despite constant innovation and development of technologies to improve efficiency, reduce environmental impact, and optimize operations in the gas and oil industry over the last few decades, there is still room to increase the efficiency of the industry's equipment in order to reduce its carbon footprint. The separation of gas from oil is a critical stage in the technological production chain, and it is carried out using high-performance multi-phase separators to limit greenhouse gas emissions and have a low impact on the environment. In this study, an improved gas–oil separator configuration was established utilizing CFD techniques. Two separator geometry characteristics were studied. Both cases have the same number of subdomains, two porous media, and four fluid zones, but with a difference in the pitch of the cyclone from the inlet subdomain. The streamlines in a cross-plan of the separator and the distribution of the oil volume fraction from the intake to the outlet were two of the numerical results that were shown as numeric outcomes. The validation of these results was performed using an experimental testing campaign that had the purpose of determining the amount of lubricating oil that is discharged together with the compressed gas at the separator outlet. [ABSTRACT FROM AUTHOR]

The article considers the development of a near-wall separation vortex arising at a supersonic flow around the external dihedral corner due to the pressure drop between its faces, in the range of angles of attack α = 0.5°–6°. The processes of the origin and development of separation and secondary vortices at the angle increase are investigated in detail. Particular attention is paid to the flow structure change in the vortex location zone. A clear violation of the flow self-similarity in the front part of the model in the zone of vortex system formation is shown. [ABSTRACT FROM AUTHOR]

At present, due to the pandemic context, air transport is being re-analysed. Especially the economy class, where most passengers travel, having six people in a row of seats becomes risky because there is no minimum distance between people. If a person is infected, they can transmit the virus very easily, even if they wear a mask. The project also contains an assessment of the possibility of transmitting the virus through the cabin ventilation system. Two ventilation solutions are simulated in Ansys Fluent, both for the current cabin configuration of a one-aisle aircraft. Next, a solution that would improve the health safety on board is proposed. The new seats and cabin configurations are designed. Firstly, the middle seat replaced with a luggage storage box, large enough to carry some "hold" luggage and secondly, a plexiglass panel support, which can be mounted on the seat backside is conceived. Finally, the air flow in aircraft cabin for this new arrangement is analysed.

This article reports a theoretical examination of two-dimensional laminar and incompressible fluid flow due to the linear stretching of a sheet. The viscous fluid flow is analyzed under the impact of the transverse uniform magnetic field. The flow is generated due to the stretching surface and its momentum and temperature distributions have been studied. The features of the flow are modeled mathematically and the nature of framed equations are fully coupled nonlinear partial differential equations. The system of governing equations is operated using an iterative finite difference scheme. This nonlinear boundary value problem is reduced to linear form using the quasilinearization technique and it is further solved using the Thomas algorithm. The numerical results are extracted and the physical behaviors of the flow are found to overlap with the outcomes. Additionally, the findings are extended to the computations of friction factor and heat transfer rate on the boundary for various pertinent parameters. The streamlines of the fluid flow are also depicted for flow controlling parameters. From the contours, the parabolic structure of the streamlines is approaching linear nature near the core of the channel with the slight increment of the physical parameters (Reynolds number, magnetic parameter, and Grashof number). [ABSTRACT FROM AUTHOR]

An abdominal aortic aneurysm (AAA) is a localized dilatation of abdominal aorta. This study investigates a 2-dimensional unsteady and laminar flow through a bifurcated artery with an aneurysm that is computationally and mathematically simulated using 3-dimensional geometry. The fluid used in this simulation is blood which is Newtonian for high shear rate. The computational technique is used to solve the equations that governs due to the flow. The flow of blood is analyzed with the assist of cut planes of pressure and velocity in the abdominal aortic aneurysm (AAA) for t = 1 s and t = 4 s. The pressure on the wall and complete velocity profile are also displayed with the assist of graphs. The streamlines are also shown with the help of graphs for t = 1 s and t = 4 s. The results can be used in the treatment of abdominal aortic aneurysm. [ABSTRACT FROM AUTHOR]

The incompressible laminar isothermal flow of a Newtonian fluid at steady state around a surface-mounted rib is studied in a three-dimensional (3D) numerical experiment. The dimensionless Navier–Stokes equations are solved numerically using the Galerkin finite element method for Reynolds numbers 1 to 800. The expansion ratio of the problem is 1:9.6, while the aspect ratio is 1:20. The transition from the steady to the unsteady state and the identification of the critical Reynolds number are investigated in this paper. Numerical results of the skin-friction lines at the bottom and streamlines throughout the computational field are presented. A comparison between the 2D and 3D flow is made to show the effect of the walls on the flow, which reaches the plane of symmetry and affects the flow there; hence, also affecting the stability of the flow. It is concluded that the flow is three-dimensional even for a Reynolds number equal to 10. The critical Reynolds number is 600, and the steady-state equations can be used for any calculations up to this value. [ABSTRACT FROM AUTHOR]

Gaussian solutions of the diffusion equation can be applied to visualize the flow paths in subsurface reservoirs due to the spatial advance of the pressure gradient caused by engineering interventions (vertical wells, horizontal wells) in subsurface reservoirs for the extraction of natural resources (e.g., water, oil, gas, and geothermal fluids). Having solved the temporal and spatial changes in the pressure field caused by the lowered pressure of a well's production system, the Gaussian method is extended and applied to compute and visualize velocity magnitude contours, streamlines, and other relevant flow attributes in the vicinity of well systems that are depleting the pressure in a reservoir. We derive stream function and potential function solutions that allow instantaneous modeling of flow paths and pressure contour solutions for transient flows. Such analytical solutions for transient flows have not been derived before without time-stepping. The new closed-form solutions avoid the computational complexity of time-stepping, required when time-dependent flows are modeled by superposing steady-state solutions using complex analysis methods. [ABSTRACT FROM AUTHOR]

Analysis of results of experimental investigation of turbine cascades is carried out. It is showed that the nature of the influence of negative incidences on profile losses can be determined by the streamline of the inlet part of the airfoil at design mode. The conditions are revealed, under which, at moderate incidences, incidence losses are negative, zero, and positive. Geometric parameters of cascades with favorable and unfavorable streamline are defined, and recommendations for choosing the optimal inlet metal angle in the designed cascades are refined. [ABSTRACT FROM AUTHOR]

This paper presents the outcome of numerical simulations of the flowfield inside the ONERA F1 wind tunnel, which is a large-scale pressurized low-speed wind tunnel mostly used to investigate the takeoff and landing performance of aircrafts in high-lift configuration. The simulations were carried out under Reynolds-averaged Navier-Stokes modeling assumptions. Results were compared to available experimental data characterizing the tunnel flowfield, especially in the test section. The overall flow physics is well captured by the simulations. However, when looking at the result with a more demanding level of accuracy, some important characteristics of the velocity distribution in the test section, such as flow upwash and total pressure distribution, are not replicated. Reasons are discussed in the paper, and some recommendations are derived for future similar simulations. [ABSTRACT FROM AUTHOR]

In this piece, the impact of an obstacle's upstream edge inclination in a rectangular channel is investigated. The main purpose of this study is to give a better understanding of this associated phenomenon by reflecting more accurately the different cooling techniques and to get as close as possible to real conditions of use. This study is based on the laws of conservation of mass, momentum, and energy, the equations are given in the case of the 2-D flow of an incompressible Newtonian fluid, depending on the variables primitives given below. During the study, we used the FLUENT computer code, as well as its GAMBIT mesh generator several times, which allowed us to become more familiar with numerical simulation. The purpose of our numerical research is to clarify physical phenomena that are described by theory without using more expensive experimentation. [ABSTRACT FROM AUTHOR]

An analytical study was carried out on an anchored circular pit with a submerged free surface in layered soil. The seepage field around the anchor circular pit was divided into three zones. Separate variable method was used to obtain the graded solution forms of head distribution in the column coordinate system for each of the three regions. Combined with the continuity condition between the regions the Bessel function orthogonality was used to obtain the explicit analytical solution of the seepage field in each region, and the infiltration line was determined. Comparison with the calculation results of Plaxis 2D 8.5 software verified the correctness of the analytical solution. Based on the analytical solution, the influence of the radius of the pit and the distance of the retaining wall from the top surface of the impermeable layer on the total head distribution on both sides of the retaining wall was analyzed. And the variation in the infiltration line was determined with the above parameters. The results show that as the pit radius, r, decreased, the total head on both sides of the retaining wall gradually increased, and the height of the submerged surface drop also increased. As the distance, a, between the retaining wall and the impermeable boundary at the bottom increased, the hydraulic head on the outer side of the retaining wall decreased and the head on the inner side increased. The height of the submerged surface drop increased with decreasing depth of insertion of the retaining wall. The depth of insertion of the retaining wall had a greater influence on the degree of diving surface drop than the pit radius.

The purpose of this study is to investigate the flow pattern and discharge coefficient of sluice gate with the non-suppressed sill in experimental and numerical conditions. For this purpose, the sill of a rectangular cube in widths of 7.5, 10, 15, and 20 cm was installed under the sluice gate. Experimental results showed that placing a non-suppressed sill under the sluice gate by creating a failure in the flow lines causes a different flow pattern compared to the without sill state. Deviation of streamlines after colliding with the sill causes the formation of V-shaped currents. The discretization of equations for simulations were performed using VOF method. After selecting a cell with a size of 0.07 cm as the optimal cell, the RNG turbulence model was used. The results of the numerical simulation showed an acceptable agreement with the experimental results. Thus, the place of formation of V-shaped currents was transferred downstream of the sluice gate by increasing the width of the sill and the inflow discharge. The results of the study of the discharge coefficient showed that the placement of the sill with a width of 7.5 and 20 cm, increased the discharge coefficient by an average of 5.3% and 15.5% in the experimental model and 4.7% and 16% in the numerical simulation. This relationship is without sill state and with sill state with root mean square error of 0.967 and 0.968, respectively, estimated the discharge coefficient of the sluice gate.

We present a trajectory-based technique for calculating solute transport in a porous medium that has several advantages over existing methods. Unlike streamlines, the extended trajectories are influenced by each of the important parameters governing transport, including molecular diffusion and transverse dispersion. The approach is complete and does not require any additional techniques, such as operator splitting or particle tracking, in order to account for the full dispersion tensor. The semianalytic expressions make it clear how the flow field, the concentration distribution, and the dispersion tensor contribute to the velocity field of an injected solute. The equations are valid for an arbitrary porous medium, including those with rapid spatial variations in properties, overcoming limitations faced by previous approaches based upon asymptotic techniques. A test on a layered model with sharp boundaries indicates that the extended trajectories are compatible with the results of a numerical simulator and differ from streamlines. We also describe a new form of the dispersion tensor that incorporates a known asymmetry. The trajectories indicate that the modifications of the dispersion tensor lead to more focused transport within regions of high conductivity. Finally, the trajectories are used to define a semianalytic relationship between solute travel times and variations in solute velocities along a path that may be used for tomographic imaging. In an application to the injection of a radioactive tracer into a Berea sandstone core, monitored using micropositron emission tomographic (micro-PET) observations, the sensitivities are used to map the spatial variations of permeability within the core.

The article considers the potential problem of a deep impulsive impact at the initial moment of time on a hydrogeophysical massif, which can occur during underground (underwater) explosions, volcanic eruptions, seismic events, etc. The impact of the pulse focus was modeled by a rounded source with a unit pressure, and the sink area was modeled by a line of zero potential. A rigorous hydromechanical solution of the problem is obtained with the establishment of an analytical relationship between the physical region of the flow and the complex potential based on the theory of the function of a complex variable, that is, the use of the method of successive conformal mappings with the determination of all necessary flow characteristics. Calculation examples are given for special cases with the construction of curvilinear orthogonal hydrodynamic grids, outlines of families of lines of equal heads and stream lines, profiles of impulse sources, as well as diagrams of velocities, heads and potential flow rates. [ABSTRACT FROM AUTHOR]