Search

The mast is a critical component of rotary drilling rigs, which has a cross-section consisting of a rectangular shape formed by two web plates and two flange plates. Structural optimization of the mast is necessary to address the issue of excessive weight. The shortcomings of the traditional structural optimization algorithms are summarized as follows: the optimized steel plate thickness is a non-integer, where rounding upwards may increase the cost to a certain extent, but it can ensure the safety of the structure; rounding downwards its load carrying capacity may not satisfy the requirements, and thus a novel Salp Swarm Algorithm is proposed to solve the optimization problem. First, this study improves the initialization and update strategy in the traditional Salp Swarm Algorithm. In order to obtain a solution for engineering, an innovative multi-dimensional running comparison is carried out. Secondly, the optimization model of rotary drilling rigs is established based on the division of the working conditions. The objective function of the optimization model is to minimize the weight of the mast while considering the constraints of strength, stiffness, stability, and welding process. Finally, the proposed optimization algorithm and the established optimization model are applied to optimize the design of the mast for a rotary drilling rig. The empirical results demonstrate that the weight of the mast has been reduced by 20%. In addition, the Improved Salp Swarm Algorithm exhibits higher solution quality, faster iteration capability, and extreme stability in optimizing welded box sections compared to the conventional algorithm. The example shows that the Improved Salp Swarm Algorithm is applicable to the optimization problem of box sections. [ABSTRACT FROM AUTHOR]

Cell micromanipulation is an important technique in the field of biomedical engineering. Microgrippers play a crucial role in connecting macroscopic and microscopic objects in micromanipulation systems. However, since the operated biological cells are deformable, vulnerable, and typically distributed in sizes ranging from micrometers to millimeters, it poses a huge challenge to microgripper performance. To solve this problem, this paper develops a dual-driven piezoelectric microgripper with a high displacement amplification ratio, large stroke, and parallel gripping. By adopting modular configuration, three kinds of flexure-based mechanisms, including the lever mechanism, Scott–Russell mechanism, and parallelogram mechanism are connected in series to realize three-stage amplification, which effectively makes up for the shortage of small output displacement of the piezoelectric actuator. At the same time, the use of the parallelogram mechanism also isolates the parasitic rotation movement, and realizes the parallel movement of the gripping jaws. In addition, the kinematics, statics, and dynamics models of the microgripper are established by using the pseudo-rigid body and Lagrange methods, and the key geometric parameters are also optimized. Finite element simulation and experimental tests verify the effectiveness of the developed microgripper. The results show that the developed microgripper allows an amplification ratio of 46.4, a clamping stroke of 2180 μ m, and a natural frequency of 203.1 Hz. Based on the developed microgripper, the nondestructive micromanipulation of zebrafish embryos is successfully realized. [ABSTRACT FROM AUTHOR]

Copyright of Urban Mass Transit is the property of Urban Mass Transit Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

AbstractThis study explores the adoption of carbon fiber reinforced plastic (CFRP) in automotive seat backrests, aiming to improve compliance with regulatory standards and enhance performance. By replacing conventional materials with CFRP, and employing mechanical performance tests alongside the principle of equal stiffness, the study tackles material failure issues. A novel multi-criteria decision-making method, coupled with an optimal Latin hypercube experimental design, is used to optimize the layup sequence. The optimized design not only meets regulatory requirements but also significantly enhances driver and passenger safety and comfort during collisions. [ABSTRACT FROM AUTHOR]

Pneumatic down-the-hole (DTH) hammer drilling technology has been used extensively in the fields of heat reservoir exploitation and geological exploration owing to its advantages of high efficiency and low pollution. However, the vibration near the bit is up to 40 g while DTH hammer drilling, which significantly affects the performance and longevity of the near-bit measurement while drilling (MWD). To enhance the environmental adaptability of the near-bit MWD in pneumatic DTH operations, a design method for a vibration-damping system based on the parameter optimization of a non-dominated sorting genetic algorithm II (NSGA-II) is proposed in this study. First, the whole structure of the near-bit MWD is designed, including the MWD sub-shell, sensors, measurement circuits, batteries, and connecting structures (the circuit unit). Secondly, this study analyzes the vibration characteristics of the pneumatic DTH hammer near the bit. According to the damping structure, the vibration response model for the circuit unit and the damping model are established. Thirdly, NSGA-II is employed to optimize the parameters of the damping model in terms of the low-frequency, high-intensity vibration characteristics near the bit in pneumatic DTH operations, thereby devising a damping scheme tailored to the unique conditions of DTH hammer drilling. Finally, vibration experiments were conducted to verify the effectiveness of the vibration-damping device. The experimental results indicate that within the vibration frequency range of 5–20 Hz and vibration level of 10–40 g, the peak attenuation rate of the circuit unit is more than 86.446%, and the improvement rate of the vibration stability of the system is more than 75.214%; the anti-vibration performance of the near-bit MWD system in DTH hammer drilling is improved remarkably. This study provides strong technical support for the stability of MWD equipment under such special working conditions. It has broad engineering application prospects. [ABSTRACT FROM AUTHOR]

AbstractPreform design refers to the intermediate geometric design between the initial tube blank and the desired product. A proper preform design can improve the formability of the tubular structure with small fillets. It is difficult to obtain a reasonable preform design based on engineering experience or trial-and-error methods. In this work, a Non-Uniform Rational B-Splines (NURBS) curve control point inversion algorithm-based approach is introduced to define and parameterize the preform cross-section profiles. The corresponding mathematical optimization model of preform cross-section shape design for tube hydroforming with low pressure is established, and an optimization procedure was accordingly proposed. In this procedure, the relationships between the design variables and responses are formulated by combining the DoE techniques with multiple surrogate models. The k-fold cross-validation strategy is adopted to quantify the performance of the candidate surrogate models on fresh datasets. The selected and verified surrogate models are integrated with the heuristic algorithm to determine the optimal preform shape. Compared to the direct hydroforming process, the optimized preform designs decreased the forming pressure of square, trapezoidal, and irregular polygonal tubes by 89.29%, 70.29%, and 32.67%, respectively. The validity of the proposed method is thus verified. [ABSTRACT FROM AUTHOR]

High-end equipment always operate in low-speed and heavy-load working environments, highlighting the need for cam-lobe hydraulic motors with excellent speed stability (< 1 r/min) and ultrahigh-power rotary output (> 1 MW). The successful operation of cam-lobe hydraulic motors relies on the circulation supply of high- and low-pressure oil. However, the switching between high-/low-pressure oil controlled by the oil distributor inevitably causes an obvious pressure impact and speed pulsation, which directly reduces the speed stability of hydraulic motors. Therefore, an optimization design approach for the oil distributor port is proposed to minimize the speed pulsation of cam-lobe hydraulic motors. In the proposed approach, a simulation model that links the oil distributor port structural parameters with the hydraulic motor speed pulsation was developed to clarify the effect of the oil distributor structural parameters on speed pulsation. Then, an orthogonal analysis method was used to identify the optimized oil distributor port structural parameters while minimizing the hydraulic motor's speed pulsation as much as possible. Finally, several experiments were conducted to validate the effectiveness and accuracy of the proposed optimization design approach. The experimental results indicate that the pulsation rate of the hydraulic motor equipped with the optimized oil distributor was 62.5% lower than that of the original motor at a working pressure of 25 MPa, which is consistent with the simulation results using the proposed optimization design approach. The findings of this study offer a feasible and effective approach to guide the design optimization of the oil distributor port for low-pulsation hydraulic motors. [ABSTRACT FROM AUTHOR]

To solve the problem of unstable precision caused by local micrometre and submicron level flexible displacement generated by the self-weight of key components in precision mechanical motion systems, a flexible moment precision compensation method is proposed for precision turning milling composite machining machines. Firstly, the mechanism of flexible moment precision compensation technology for spindle components, linear motion pair components, column support posture, bed body and flat table contact was analysed. Secondly, the optimization design method for flexible moment precision compensation was proposed. Finally, the optimization design of flexible moment precision compensation was carried out for spindle components, bed body and base. The flexible moment compensation method proposed in the article has important reference value for improving the precision and stability of machine tools. [ABSTRACT FROM AUTHOR]

Pipeline transportation is one of the common methods in the industrial field. Due to the diverse requirements of pipeline diameter and type, pipeline maintenance and inspection pose significant challenges with high labor costs and associated risks. To address maintenance and maintenance issues for pipelines of different diameters and types, an articulated variable-diameter pipe climbing robot was designed. The climbing pattern of the pipe climbing robot was studied, and a novel tightening mechanism was designed by replacing rotation with movement to increase the range of diameter variation. A gear-driven flipping mechanism was designed to stabilize the flipping mechanism. From aspects such as gripping force, forward and backward movement, rotation, and obstacle-crossing posture, an analysis of the obstacle-crossing characteristics of the articulated variable-diameter pipe climbing robot was conducted. The analysis indicated that the articulated variable-diameter pipe climbing robot can flexibly traverse various types of pipelines to complete obstacle-crossing actions. In the analysis process, in order to stabilize the robot's movement, a statics analysis of the drive wheel bracket was conducted, and the mechanical structure of the bracket was optimized to make the prototype's overall structure more reasonable. [ABSTRACT FROM AUTHOR]

Population growth, coupled with industrial and agricultural development, has resulted in increased demand for freshwater supply. For countries with scarce water resources, desalination constitutes the only viable solution to this problem. Reverse osmosis (RO) technology has become widely used as the membrane materials have been upgraded and the costs have been reduced. Nowadays, RO is the foremost technology for desalting different types of water such as seawater, brackish, and tap water. However, its design is critical since many parameters are involved in obtaining a good design. The high use of RO encourages the establishment of a procedure that facilitates the design process and helps in obtaining an optimum-performance RO desalination system. This paper presents a procedure divided into three parts: (1) classifying RO parameters; (2) choosing the parameters in a certain order and doing the calculation process through 12 steps; and (3) then inserting the selected parameters and the obtained values on RO System Analysis (ROSA) software. These points are then summarized by creating an algorithmic chart to follow during the design phase of the RO system using ROSA. An example on the proposed list is then taken to validate the procedure, and a comparison is conducted on choosing different values for the parameters. The results of this comparative study show that choosing different parameters affects the RO system productivity. Additionally, every design has a specific optimum set of parameters, which depends upon the design constraints set by the user. [ABSTRACT FROM AUTHOR]

Concrete-lined pressure tunnels have been widely used for water conveyance in pumped storage hydropower. With increasing internal water pressure, the tunnels are at higher risk of leakage, and the flow regime in the surrounding rocks is likely to transition from laminar to non-Darcian. Grouting has been considered as a cost-effective technique for controlling leakage in pressure tunnels, and an optimization design is usually needed to save the cost. This study proposes to use the Forchheimer's law-based model for design optimization of grouting for a concrete-lined tunnel in hard rocks subjected to 8 MPa internal water pressure. The hydraulic conductivity K of the surrounding rocks is determined from packer tests, and the excavation-induced K variation is characterized by an equivalent elasto-plastic model. The non-Darcian coefficient β is estimated from K with a calibrated power-law scaling. It is proposed that a proper design of grouting should be able to limit the region with significant non-Darcian effect within the grouted zone, in addition to other commonly-used criteria for leakage, seepage erosion and fracturing failure in the surrounding rocks. It is found that when the quality of grouting is controlled to a standard of K = 6 × 10−8 m/s, the optimal depth of grouting is 6 m in fractured rocks and 12 m in fault zones. Hydraulic tests and seepage measurements confirm that this design scheme has been well implemented at the site, and is effective in controlling pore pressure and leakage to the level predicted by the Forchheimer's law-based simulation. Highlights: The quality control criterion and depth of grouting are optimized with Forcheimer's law-based flow simulation for a pressure tunnel. It is proposed that significant non-Darcian flow effect should be limited within the grouted zone for optimization design of grouting. The optimized design scheme of grouting was implemented, and its effectiveness in leakage control is validated by seepage measurements. [ABSTRACT FROM AUTHOR]

To improve the reliability of the glass fiber-reinforced plastic (GFRP) mortar culvert structure more effectively, their failure modes were estimated by combining the Tsai–Wu and Tang failure criteria. The reliability of GFRP mortar culverts was analyzed using the Monte Carlo method. According to the characteristics of structure of GFRP mortar pipe culvert, the adaptive adjustment weights were introduced to improve the whale optimization (WOA) algorithm. The improved WOA algorithm was used to optimize the structure design of the GFRP mortar pipe culvert with its reliability as the objective function under a certain weight. It was determined that the laminated structure produces different optimal lamination angles with different relative thicknesses of single layers. As the number of layers increases, the optimal angle of fibers increases significantly. The optimization based on three design variables gave better results than based on two design variables. It was determined the optimal characteristics to reach maximum reliability of structure of GFRP mortar pipe culvert. [ABSTRACT FROM AUTHOR]

Background: Blood clots are composed of aggregated fibrin and platelets, and thrombosis is the body's natural response to repairing injured blood vessels or stopping bleeding. However, when this process is activated abnormally, such as in a mechanical blood pump, it can lead to excessive thrombus formation. Therefore, how to avoid or reduce the probability of thrombus formation is an important indicator of the stable operation of a blood pump. Methods: In this paper, Lagrangian particle tracking trajectories are simulated to study platelet transport in a blood pump. The design of the thrombus blood pump was optimized using an orthogonal design method based on three factors: inlet angle, outlet angle, and blade number. The effect of blood pump pressure, rotational speed, impeller outlet angle, inlet angle, and number of blades on thrombus formation was analysed using Fluent software. The thrombogenic potential was derived by analyzing the trajectory and flow parameters of platelet particles in the blood pump, as well as the statistical parameters of residence time and stress accumulation thrombus in the platelet pump. Results: When the impeller inlet angle is 30°, the outlet angle is 20°, and the number of blades is 6, the probability of thrombus formation is minimized in the orthogonal design method, aligning with the requirements for blood pump performance. Conclusions: These design parameters serve as a numerical guideline for optimizing the geometry of the semi‐open impeller in blood pumps and provide a theoretical foundation for subsequent in vitro experiments. [ABSTRACT FROM AUTHOR]

The elliptic shock wave has potential applications in the design of hypersonic inlets and waveriders. In this study, an optimization design process and a mathematical model for an elliptic shock wave are proposed. An elliptic cone flow field is employed to generate an elliptic shock wave whose shape is predetermined using the value of aspect ratio. The design of the shock wave is transformed into an optimization problem, and an optimization design process with the gas viscosity considered is developed. The elliptic cone is parameterized, and the parameters are adjusted by an optimization algorithm to meet the requirements. The results show that the optimization process can realize the accurate design of an elliptic shock wave. Based on the analysis of the elliptic cone flow field, the shock wave can be well approximated as an elliptic cone, and the aspect ratio of the shock wave is positively correlated with three factors: the aspect ratio and slenderness ratio of the elliptic cone and the incoming Mach number. The relationship between the aspect ratio of the shock wave and these three factors is modeled by a feed-forward neural network with accuracy verified, which is beneficial for the rapid design of elliptic shock waves. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Dalian University of Technology / Dalian Ligong Daxue Xuebao is the property of Journal of Dalian University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Plastics Science & Technology / Suliao Ke-Ji is the property of Plastics Science & Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A high-precision focusing mechanism was designed using a flexible hinge to address the demand for precise focusing in space cameras. Firstly, a finite element model of the liner guideway was created using Hertz contact theory, and the accuracy of the model was confirmed using the "flip method". Subsequently, the flexible hinge was optimized by a mix of topological and integrated optimization. The simulation results demonstrated that the improved flexible hinge successfully eliminates interference between the liner guideway and the screw, minimizes the effects of initial assembly mistakes, and greatly reduces the tilt error of the focusing mechanism. Afterward, the focusing mechanism was subjected to a vibration test, which showed that its first-order fundamental frequency reached 163.28 Hz. This frequency is sufficiently high to minimize the risk of resonance during the launch phase. Ultimately, the tilt error of the focusing mechanism was assessed using both a rigid connector and a flexible hinge. The findings demonstrated that implementing the flexible hinge resulted in a 55.7% decrease in the range of Δθz and a 55.22% reduction in the standard deviation, effectively fulfilling the specified design requirements. This study indicates that the inclusion of a flexible hinge in the focusing mechanism leads to a substantial decrease in tilt error. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chongqing University of Technology (Natural Science) is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Architecture & Civil Engineering is the property of Chang'an Daxue Zazhishe and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Southeast University / Dongnan Daxue Xuebao is the property of Journal of Southeast University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

High-rise intake towers in high-intensity seismic areas are prone to structural safety problems under vibration. Therefore, effective and low-cost anti-seismic engineering measures must be designed for protection. An intake tower in northwest China was considered the research object, and its natural vibration characteristics and dynamic response were first analyzed using the mode decomposition response spectrum method based on a three-dimensional finite element model. The non-dominated sorting genetic algorithm-II (NSGA-II) was adopted to optimize the anti-seismic scheme combination by comprehensively considering the dynamic tower response and variable project cost. Finally, the rationality of the original intake tower antiseismic design scheme was evaluated according to the obtained optimal solution set, and recommendations for improvement were proposed. The method adopted in this study may provide significant references for designing anti-seismic measures for high-rise structures such as intake towers located in high-intensity earthquake areas. [ABSTRACT FROM AUTHOR]

The design of the high-speed on/off valve is challenging due to the interrelated structural parameters of its driving actuator. Hence, this study proposes a multi-objective optimization approach that integrates a backpropagation neural network and artificial fish swarm algorithm optimization techniques to accurately model the electromagnetic solenoid structure. The backpropagation neural network is fitted and trained using simulation data to obtain a reduced-order model of the system, enabling the precise prediction of the system's output based on the input structural parameters. By employing the artificial fish swarm algorithms, with optimization objectives focusing on the valve's opening and closing times, a Pareto optimal solution set comprising 30 solutions is generated. Utilizing the optimized structural parameters, a prototype is manufactured and an experimental setup is constructed to verify the dynamic characteristics and flow pressure drop. The high-speed on/off valve achieves an approximate opening and closing time of 3 ms. Notably, the system output predicted using the backpropagation neural network (BPNN) exhibits consistency with the experimental findings, providing a reliable alternative to mathematical modeling. [ABSTRACT FROM AUTHOR]

Purpose:In order to realize the efficient utilization of ultra-fine iron tailings in bubble mixed light soil, the mix proportion optimization design was carried out with the optimal mechanical properties as the goal. Method; Based on BBD response surface method,the optimized design of the mix ratio was carried out by taking the tailings content of 15% -- 30%,the foam content of 4% -- 6%,and the water-material ratio of 0. 4 -- 0.6 as variables,and the compressive strength of 7 d and 28 d as response values. A total of 17 groups of mixed proportions were designed. The influence degree of interaction among components on compressive strength was analyzed. Result; The foam content has the most significant influence on the compressive strength of ultra-fine iron tailings foamed mixture lightweight soil,followed by the water-material ratio and tailings content. From the perspective of the interaction of the two factors, the interaction of tailings and foam content has the most significant effect on the compressive strength. By solving the extreme value of the regression model, when the tailings content is 34. 19%, the foam content is 4. 34%and the water-material ratio is 0. 45, the ultra-fine iron tailings foamed mixture lightweight soil has the optimal mechanical properties. Conclusion; The optimized ultra-fine iron tailings foamed mixture of lightweight soil can meet the technical requirements of filling engineering. [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Geology & Recovery Efficiency is the property of Petroleum Geology & Recovery Efficiency and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Aviation fuel pump has the problem of flow-induced noise in engineering application，which can affect the unit operation stability and staff's working security. To solve these problems，the noise reduction technique for fuel pump is introduced. Firstly，the noise data of fuel pump acquired during the on-land system test of air plane is tested，and the noise amplitude and frequency are analyzed. Then，numerical simulation is conducted to understand the flow regime in the fuel pump. Finally，the optimization design is conducted for impeller and guide vane of fuel pump. The results show that the main reason of flow-induced noise is the pressure fluctuation caused by rotor-stator interaction between impeller and guide vane. The pressure fluctuation can be reduced by increasing the impeller and vane blade number and applying the alternate loading technique. After optimization，the noise of fuel pump is decreased by 6.5 dB.

Objective The restriction and impact of balises in the maintenance trench of automated vehicle depots on vehicle maintenance grow increasingly prominent. Therefore, it is necessary to conduct a research on the variable-position scheme of self-resetting weight-driven pulling type in balise variable-position system. Method Based on the actual requirements of vehicle maintenance processe, a three-level architecture for the balise variable-position system is designed, comprising master control console, electric control cabinet, and variable-position mechanism. The system supports multiple control modes, including manual direct control, interlinked control with intelligent vehicle inspection robots, and automatic interlinked control with signaling system SPKS (staff protection key switch), ensuring operational flexibility and precision. Additionally, the system is equipped with safety redundancy measures such as built-in laser positioning detection and manual locking to meet the stringent reliability requirements of the signaling system. Result & Conclusion In practical application within vehicle depots, the balise variable-position system effectively utilizes the spatial gaps between track bridge support columns, enabling the transition from fixed to variable-position balise mounting. This revolution not only ensures precise and efficient FAO (fully automatic operation) train dispatching and receiving, but also significantly facilitates convenience in the work of depot inspection personnel and intelligent inspection robots, effectively addressing the limitations imposed on maintenance operations by fixed balise mounting.

The aerodynamic performance of axial compressor rotors is negatively affected by the ingestion of boundary layer fluids upstream. As the boundary layer becomes thicker, the blade tip load increases and the local loss is aggravated, especially under off-design operating conditions. The major objective of this research is to evaluate the potential for novel blade sweep designs that can tolerate the ingested low-momentum boundary layer fluids. An optimization design approach using a surrogate model and genetic algorithm is employed. By altering the blade stacking line, the optimized sweep design is obtained. The flow mechanisms that enable the performance of the compressor rotor to be improved are fully analyzed, and the findings indicate that the aerodynamic advantages primarily stem from two key aspects. First, in the tip region, the blade loads are decreased at various chordwise locations and the interaction of the tip leakage flow with the mainstream is alleviated. As a result, the loss near the tip is reduced. Second, the blade sweep design alters the distribution of shock intensity across the spanwise direction, leading to a decrease in shock wave intensity in the mid-span region. This is beneficial in reducing the shock wave/boundary layer interaction strength at the trailing edge of the blade airfoil. Overall, after the sweep design has been optimized to ingest the upstream boundary layer, the compressor rotor experiences a 0.8% improvement in adiabatic efficiency compared with the baseline rotor, while preserving the total pressure ratio and stall margin. Additionally, the redesigned compressor retains the overall performance level under clean inlet conditions. This research provides a potentially effective blade sweep optimization design strategy that allows transonic compressor rotors to tolerate low-momentum upstream boundary layer incoming flows.

CO2 capture， utilization， and storage （CCUS） can achieve a win-win situation of carbon emission reduction and oil production increase， and it is a key technology for the green and low-carbon transformation of the fossil energy industry. The petroleum and petrochemical industries have accelerated the large-scale application of CCUS technology after China proposed the goals of “peaking carbon emissions before 2030 and achieving carbon neutrality before 2060” in September 2020. It has gradually been revealed that CO2 flooding has contradictions such as a low impact， short effective time， and rapid increase in the gas-oil ratio in the field practices of SINOPEC Shengli Oilfield and CNPC Jilin Oilfield. It is necessary to strengthen the optimization design of reservoir engineering further. This article systematically analyzed field practices of CO2 flooding to enhance oil recovery in sandstone reservoirs in China and abroad and key issues in the optimization design of reservoir engineering， such as the matching between reservoir pressure maintenance level and miscible pressure， between well pattern direction and formation stress direction， between well spacing and reservoir permeability， and optimization of gas-water alternative displacement methods combined with the research results of the million-ton CCUS demonstration project in Shengli Oilfield. Then， the article summarized the latest progress in reservoir engineering research， such as reservoir pressure maintenance level during CO2 flooding， well network， well spacing， and gas-water alternative displacement， and analyzed the increasing pressure method， well pattern， well spacing， and gas-water alternative displacement optimization design for high-pressure miscible flooding. Finally， it indicated that the research direction of CO2 flooding reservoir engineering design should focus on the phase and flow laws of crude oil， CO2， and water in porous media under high-pressure conditions， the synergistic mechanism of CO2 flooding and storage， and the gas channeling mechanism of CO2 flooding under complex reservoir conditions. This article provides technical support for large-scale CO2 flooding in China.

Abstract High-end equipment always operate in low-speed and heavy-load working environments, highlighting the need for cam-lobe hydraulic motors with excellent speed stability (< 1 r/min) and ultrahigh-power rotary output (> 1 MW). The successful operation of cam-lobe hydraulic motors relies on the circulation supply of high- and low-pressure oil. However, the switching between high-/low-pressure oil controlled by the oil distributor inevitably causes an obvious pressure impact and speed pulsation, which directly reduces the speed stability of hydraulic motors. Therefore, an optimization design approach for the oil distributor port is proposed to minimize the speed pulsation of cam-lobe hydraulic motors. In the proposed approach, a simulation model that links the oil distributor port structural parameters with the hydraulic motor speed pulsation was developed to clarify the effect of the oil distributor structural parameters on speed pulsation. Then, an orthogonal analysis method was used to identify the optimized oil distributor port structural parameters while minimizing the hydraulic motor’s speed pulsation as much as possible. Finally, several experiments were conducted to validate the effectiveness and accuracy of the proposed optimization design approach. The experimental results indicate that the pulsation rate of the hydraulic motor equipped with the optimized oil distributor was 62.5% lower than that of the original motor at a working pressure of 25 MPa, which is consistent with the simulation results using the proposed optimization design approach. The findings of this study offer a feasible and effective approach to guide the design optimization of the oil distributor port for low-pulsation hydraulic motors.

Thin-Walled Structures (TWS) play a crucial role in enhancing both the collision safety and lightweight characteristics of vehicles. Structural design and optimization have demonstrated significant potential in improving their crashworthiness and overall weight reduction. Several interconnected factors, including the cross-sectional shape and parameters of distinctive structural characteristics (known as induction grooves), impact the TWS' resistance to collisions. Another critical aspect in the optimization of TWS design is striking the delicate balance between the surrogate model's effectiveness and precision. Taking all these factors into account, this paper conducts an in-depth investigation into the cross-sectional shape, grooves, and other geometric attributes of various TWSs through a comparative analysis. It reveals that the thin-walled structure with a Double-Ribbed Rectangle cross-section (DR-TWS) proves to be the optimal choice, particularly in low-speed axial impact scenarios. Furthermore, we present an enhanced Least Squares Support Vector Machine (LSSVM) method, augmented with an adaptive T -distribution Sparrow Search Algorithm (TSSA), referred to as the TSSA-LSSVM surrogate model. The optimized design of the DR-TWS is realized through the integration of the TSSA-LSSVM surrogate model with the adaptive hybrid multi-objective particle swarm optimization (AHMOPSO) algorithm. This paper not only provides substantial theoretical support but also offers valuable guidelines for the application of TWSs in the automotive industry. [ABSTRACT FROM AUTHOR]

The aerodynamic performance of axial compressor rotors is negatively affected by the ingestion of boundary layer fluids upstream. As the boundary layer becomes thicker, the blade tip load increases and the local loss is aggravated, especially under off-design operating conditions. The major objective of this research is to evaluate the potential for novel blade sweep designs that can tolerate the ingested low-momentum boundary layer fluids. An optimization design approach using a surrogate model and genetic algorithm is employed. By altering the blade stacking line, the optimized sweep design is obtained. The flow mechanisms that enable the performance of the compressor rotor to be improved are fully analyzed, and the findings indicate that the aerodynamic advantages primarily stem from two key aspects. First, in the tip region, the blade loads are decreased at various chordwise locations and the interaction of the tip leakage flow with the mainstream is alleviated. As a result, the loss near the tip is reduced. Second, the blade sweep design alters the distribution of shock intensity across the spanwise direction, leading to a decrease in shock wave intensity in the mid-span region. This is beneficial in reducing the shock wave/boundary layer interaction strength at the trailing edge of the blade airfoil. Overall, after the sweep design has been optimized to ingest the upstream boundary layer, the compressor rotor experiences a 0.8% improvement in adiabatic efficiency compared with the baseline rotor, while preserving the total pressure ratio and stall margin. Additionally, the redesigned compressor retains the overall performance level under clean inlet conditions. This research provides a potentially effective blade sweep optimization design strategy that allows transonic compressor rotors to tolerate low-momentum upstream boundary layer incoming flows. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Shanghai Jiaotong University (Science) is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract This work aims to explore optimization methods for the design of earthen buildings in rural Fujian to achieve low-carbon emissions and improve the structural stability of earthen buildings. First, parametric modeling and optimization algorithms are employed through the Grasshopper platform. An intelligent earthen building design is created by combining the optimization of factors such as the structure of earthen buildings, building materials, and orientation. Then, a comparison is made with the unoptimized, energy-efficient, and carbon emission reduction designs. Finally, the work concludes that the proposed design significantly optimizes the total carbon emissions, energy consumption, structural stability, and economic aspects. The proposed design scheme achieves the highest carbon emission reduction effect, with a reduction rate of 34.64%. The proposed design exhibits lower maximum stress and higher minimum safety factor in terms of structural stability compared to other scenarios, along with smaller structural displacement. It also performs well in terms of initial investment, annual operating costs, and construction period. The significance of this work lies in providing scientific guidance for the design and construction of rural earthen buildings, promoting the organic integration of rural development with low-carbon initiatives. This indicates that the use of intelligent optimization methods for earthen building design is feasible and can yield positive results in practice.

The existing research on waterfront tour route planning suggests that thermal comfort assessment has a direct impact on people’s outdoor tour experiences. It contributes to understanding the thermal comfort regulation mechanisms of landscape nodes and the scientific planning of tour routes. However, the research in this area is relatively limited and faces complex issues in data processing and analysis. This study takes the West Lake waterfront tour route in Hangzhou, China, as an example. Through empirical research, it validates the feasibility of tour route planning guided by thermal comfort. It employs field surveys, on-site measurements, and data analysis methods primarily based on the Rayman software to explore the relationship between urban outdoor waterfront spaces and microclimates. The study reveals the following findings: (i) Extensive water bodies surrounding an area positively regulate local microclimates. The closer one is to the water and the more water surrounds the area, the stronger the microclimate effect. (ii) Factors such as spatial openness, waterfront orientation, prevailing monsoons, etc. all have certain impacts on the microclimates of the lake and lakeside spaces. (iii) Air temperature has significant variability in its impact on human thermal comfort, with different PET (Physiological Equivalent Temperature) values at each measurement point during different time periods. The study combines the actual human thermal comfort conditions at eight measurement points around the lake with existing tour routes. It proposes two practical tour route optimization designs based on real tour microclimate factors. These designs employ thermal comfort assessment methods to effectively enhance and improve human thermal comfort during tours. This research carries social value and provides new insights for mitigating urban waterfront space microclimates, enhancing tour comfort, and improving landscape environments.

In order to realize the intelligent optimization design of cavitation performance of fuel centrifugal pump, a multi-stage active learning adding strategy based on Kriging is proposed. The focus is to establish the three-stage adding strategy by using MSE, EI and CV, and clarify the switching criteria for each stage. Based on the test functions such as one-dimensional function and multi-dimensional function, it is compared with the single-stage adding strategy to verify the effectiveness of the proposed strategy. Furthermore, for a certain type of fuel centrifugal pump, the optimization application of the proposed strategy in its cavitation characteristics is completed. The result of the test function calculation shows that the proposed strategy takes slightly longer to achieve the same accuracy than MSE, which is better than EI and CV. However, compared with MSE, the local accuracy of the global optimal solution is higher. The result of centrifugal pump case shows that the pressure loss at the inlet of the optimized pump decreases, the local flow such as return flow and vortex at the inlet is weakened, the pressure gradient and the vortex flow in the volute weakens. Moreover, the cavitation coefficient of the optimized pump is increased by 30.83%, the NPSH allowance is reduced by 9.14%, the cavitation ratio is reduced by 7.17%, and the gas content in the pump is reduced by 17.27%. Thus, the proposed method improves the cavitation performance of the centrifugal pump effectively.

Population growth, coupled with industrial and agricultural development, has resulted in increased demand for freshwater supply. For countries with scarce water resources, desalination constitutes the only viable solution to this problem. Reverse osmosis (RO) technology has become widely used as the membrane materials have been upgraded and the costs have been reduced. Nowadays, RO is the foremost technology for desalting different types of water such as seawater, brackish, and tap water. However, its design is critical since many parameters are involved in obtaining a good design. The high use of RO encourages the establishment of a procedure that facilitates the design process and helps in obtaining an optimum-performance RO desalination system. This paper presents a procedure divided into three parts: (1) classifying RO parameters; (2) choosing the parameters in a certain order and doing the calculation process through 12 steps; and (3) then inserting the selected parameters and the obtained values on RO System Analysis (ROSA) software. These points are then summarized by creating an algorithmic chart to follow during the design phase of the RO system using ROSA. An example on the proposed list is then taken to validate the procedure, and a comparison is conducted on choosing different values for the parameters. The results of this comparative study show that choosing different parameters affects the RO system productivity. Additionally, every design has a specific optimum set of parameters, which depends upon the design constraints set by the user.

Abstract An air spring (AS) for ships must have the structural strength of its bellows enhanced considerably to ensure its reliability under high internal pressure and strong impact. In this case, the stiffness of the bellows gradually dominates the overall stiffness of the AS. Nevertheless, the parameterization calculation of stiffness for an AS mainly focuses on its pneumatic stiffness. The bellows stiffness is normally analyzed by virtue of equivalent simplification or numeric simulation. There is not an effective parameterization calculation model for the stiffness of the bellows, making it difficult to achieve the structural optimization design of the bellows. In this paper, the shell theory was borrowed to build a mechanical model for the bellows. Subsequently, the state vector of the bellows was solved by precision integration and boundary condition. Iteration was conducted to identify the complex coupling relationship between the vector of the bellows and other parameters. On this basis, the parameterization calculation method was introduced for the stiffness of the bellows to obtain the vertical and horizontal stiffness of the AS. After that, a dual-membrane low-stiffness structure was designed to analyze the dominating factors affecting the strength and stiffness of the AS, which highlighted the way to the low-stiffness optimization design of high-strength ASs. In the end, three prototypes and one optimized prototype were tested to verify the correctness of the parameterization design model for stiffness as well as the effectiveness of the structural optimization design.

The study introduces an enhanced concentric spiral-coil EMAT to tackle low signal-to-noise ratio (SNR) in high-temperature carbon steel forging defect detection. With a non-overlapping concentric coil design, simulations and experiments were conducted, utilizing a finite element model with circuit-field coupling to optimize parameters. Results show the improved EMAT enhances SNR by up to 20.96 dB compared to traditional designs. High-temperature tests demonstrate its capability to detect Ф5 mm holes at 650℃, with SNR increasing by 11.24 dB as temperature rises from 100℃ to 500℃, validating the optimization method’s effectiveness. [ABSTRACT FROM AUTHOR]

Kinematic coupling, as an efficient form of connection, is frequently employed for the repeated assembly and accurate positioning of replaceable opto-mechanical assemblies within high-power solid-state laser systems. During the kinematic coupling process, uncertainties in the mechanical behavior within the contact region often hinder the attainment of consistent positioning precision, potentially leading to an inability to meet operational requirements. This study aims to enhance the repetitive positioning precision of kinematic couplings. A predictive model for repetitive positioning precision is established, accounting for uncertainties in contact region forces. Based on this model, an optimization design of kinematic couplings is conducted to mitigate these challenges. Initially, accounting for uncertainties in mechanical parameters within the contact region, we formulate a static analysis computational model to elucidate the probabilistic distribution of these parameters. Subsequently, employing Hertz contact theory and Holm-Archard wear theory, we quantify the elastic deformation and equivalent wear for each contact region through the calculation of normal pressures. Building upon this foundation, we establish a predictive model for repetitive positioning precision. Finally, optimization design is carried out on the friction coefficient of contact surfaces and the structural dimensions of positioning elements. The proposed optimization design is validated through experimental verification. The findings demonstrate that optimization of structural dimensions and contact surface friction coefficients resulted in enhanced repetitive positioning precision of 35.9 %, effectively ameliorating the assembly quality. This study contributes a quantifiable analytical approach to the prediction and optimization design of repetitive positioning precision in kinematic couplings. • Repetitive positioning precision is the most critical performance indicator for kinematic couplings. • Simplify the stress, deformation and wear situation in 3D space for symmetrical structures into a plane for analysis. • A new method for predicting repeated positioning precision based on the uncertainty of mechanical parameters is proposed. • The concept that there exists a critical value for the deviation error affected by the initial deviation is proposed. [ABSTRACT FROM AUTHOR]

The propeller performance of small loitering munition is easily affected by the smaller blade size and lager hub ratio. A loitering munition encountered the problems of propeller speed is too high, and the endurance is not enough, the propeller wind tunnel test, the calculation results and flight performance are different. Aiming at the problem of inconsistent calculation results, the numerical simulation of the experimental subject was carried out. The result shows that the propeller hub produces a large negative thrust and torque, which is the most important factor leading to a significant decrease in propeller efficiency and increase in propeller speed. According to the calculation results, the formula of the hub thrust and torque correction and the propeller optimization design are given. In view of the large difference between the wind tunnel test efficiency value and flight performance, the propulsion system wind tunnel test was carried out, the problem of incoming flow interference is solved and accurate experimental results are obtained. In order to improve propeller efficiency, a propeller calculation model is derived based on propeller vortex theory, the optimization design of propeller aerodynamic profile is carried out by using genetic algorithm toolbox, with the efficiency of propeller at cruise as objective, the thrust and maximum counter torque in climb as constraints. The design results are verified by the wind tunnel test of the propulsion system. Experimental results show that the optimized design is effective, and the propeller efficiency is increased by 17.2% at cruise. [ABSTRACT FROM AUTHOR]

Electromagnet coil is mainly composed of enameled wire which wound on the coil skeleton, and the function is to convert the electrical signal into a magnetic signal, which is a very important electric‐magnetic conversion element. When designing the electromagnet coil, usually only the total winding turns and winding inner diameter can be calculated, and the specific design parameters such as the diameter of copper wire, paint layer thickness, and winding turns of each layer can only be selected through experience, indicating that the design method should be improved. In addition, the unreasonable design parameters will seriously affect the power consumption and cost of coil, so it is highly necessary to improve the optimization design method. In order to solve the above problems, an optimization design method for DC electromagnet coil is proposed in this paper. This method simultaneously takes into account both power consumption and manufacturing cost, and can achieve the optimal matching of design parameters. In this paper, the structure of electromagnet coil is introduced, and the theoretical calculation model of resistance is improved first. Then, according to the expected requirements of electromagnet coil for steady current, the optimization design method is proposed and the optimal design parameters are obtained. Finally, the effectiveness of the proposed optimization design method is verified by the test platform of electromagnet coil. The results show that the electromagnet coil designed by the optimization design method fully meets the expected requirements. The relevant research results can provide reference for the optimization design of electromagnet coil, which has a certain engineering practical value. © 2024 Institute of Electrical Engineers of Japan and Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Restoring campus pedestrian spaces is vital for enhancing college students' mental well-being. This study objectively and thoroughly proposed a reference for the optimization of restorative campus pedestrian spaces that are conducive to the mental health of students. Eye-tracking technology was employed to examine gaze behaviors in these landscapes, while a Semantic Difference questionnaire identified key environmental factors influencing the restorative state. Additionally, this study validated the use of virtual reality (VR) technology for this research domain. Building height difference (HDB), tree height (HT), shrub area (AS), ground hue (HG), and ground texture (TG) correlated significantly with the restorative state (ΔS). VR simulations with various environmental parameters were utilized to elucidate the impact of these five factors on ΔS. Subsequently, machine learning models were developed and assessed using a genetic algorithm to refine the optimal restorative design range of campus pedestrian spaces. The results of this study are intended to help improve students' attentional recovery and to provide methods and references for students to create more restorative campus environments designed to improve their mental health and academic performance. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to improve the crashworthiness of the novel circular-vein branched nested tube (CVBNT) proposed in recent research work, the crashworthiness design is optimised in this paper. Based on numerical simulation technology, the finite element model under transverse quasi-static compression of CVBNT is first established and effectively verified. Then, the energy absorption characteristics of CVBNT and different nested tubes were compared and analysed to reveal the excellent energy absorption performance of CVBNT. Finally, the structural design and the cross-sectional thickness optimisation of CVBNT are carried out. The results show that CVBNT has better energy absorption capacity than other nested tubes. The parameters N and γ have an important influence on the crashworthiness of CVBNT, and when N = 6, γ = 0.5 is the best choice in favour of its crashworthiness. At the same time, the optimisation of cross-section thickness effectively improves the crashworthiness of CVBNT. [ABSTRACT FROM AUTHOR]

Copyright of Machine Tool & Hydraulics is the property of Guangzhou Mechanical Engineering Research Institute (GMERI) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Packaging & Food Machinery is the property of Packaging & Food Machinery Magazine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Foundation treatment piles are crucial for enhancing the bearing capacity and stability of weak foundations and are widely utilized in construction projects. However, owing to the complexity of geological conditions, traditional construction methods fail to meet the demand for low-carbon development. To address these challenges, this study introduced a comprehensive decision-making approach that considers the impact of stratum variability on greenhouse gas (GHG) emissions and pile bearing capacity from the design phase. During the design process, the GHG emissions and bearing capacities of deep cement mixing (DCM) and high-pressure jet grouting (HPJG) piles were quantitatively assessed by analyzing the environmental and performance impacts of foundation treatment piles related to materials, transportation, and equipment usage. The results suggest that the bearing capacity of piles in shallow strata is highly susceptible to stratum variability. Using piles with a diameter of 800 mm and a length of 20 m as an example, compared with DCM piles, HPJG piles demonstrated a superior bearing capacity; however, their total GHG emissions were 6.58% higher, primarily because of the extensive use of machinery during HPJG pile construction. The GHG emissions of foundation treatment piles in shallow strata were influenced more by geological variability than those in deep strata. Sensitivity analysis revealed that the pile diameter is a critical determinant of GHG emissions and bearing capacity. Based on the bearing capacity–GHG emission optimization framework, a foundation treatment strategy that integrates overlapping and spaced pile arrangements was introduced. This innovative construction method reduced the total GHG emissions by 22.7% compared with conventional methods. These research findings contribute to low-carbon design in the construction industry. [ABSTRACT FROM AUTHOR]