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Regression analysis of squeezing-induced hybrid nanofluid flow in Darcy-Forchheimer porous medium

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 193-208页

作者： K.MUHAMMAD M.SARFRAZ department of Humanities and Sciences School of Electrical Engineering and Computer Science National University of Sciences and Technology department of Mathematics Quaid-i-Azam University

This article presents a mathematical model addressing a scenario involving a hybrid nanofluid flow between two infinite parallel plates. One plate remains stationary, while the other moves downward at a squeezing velocity. The space between these plates contains a Darcy-Forchheimer porous medium. A mixture of water-based fluid with gold(Au) and silicon dioxide(Si O2) nanoparticles is formulated. In contrast to the conventional Fourier's heat flux equation, this study employs the Cattaneo-Christov heat flux equation. A uniform magnetic field is applied perpendicular to the flow direction, invoking magnetohydrodynamic(MHD) effects. Further, the model accounts for Joule heating, which is the heat generated when an electric current passes through the fluid. The problem is solved via NDSolve in MATHEMATICA. Numerical and statistical analyses are conducted to provide insights into the behavior of the nanomaterials between the parallel plates with respect to the flow, energy transport, and skin *** findings of this study have potential applications in enhancing cooling systems and optimizing thermal management strategies. It is observed that the squeezing motion generates additional pressure gradients within the fluid, which enhances the flow rate but reduces the frictional drag. Consequently, the fluid is pushed more vigorously between the plates, increasing the flow velocity. As the fluid experiences higher flow rates due to the increased squeezing effect, it spends less time in the region between the plates. The thermal relaxation, however, abruptly changes the temperature, leading to a decrease in the temperature fluctuations.

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Multidisciplinary Design Optimization with a New Effective Method

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Chinese Journal of Mechanical engineering 2010年第4期23卷 505-510页

作者： CHEN Xiaokai LI Bangguo LIN Yi National engineering Laboratory of electric vehicle Beijing Institute of Technology Beijing 100081 China

Collaborative optimization （CO） is one of the most widely used methods in multidisciplinary design optimization （MDO）, which is an effective methodology to solve modem complex engineering problems. CO consists of two-level optimization problems which are system optimization problem and subspace optimization problem. The architecture of CO can reserve the autonomy of individual disciplines in maximum, while providing a mechanism for coordinating design problem. However, CO has low computation efficiency and is easy to diverge. For the purpose of solving these problems, the former improved methods were studied. The relaxation factors were used to change the system consistency constraints to inequality constraints, or the response surface estimation was used to surrogate the system consistency constraints. However, these methods didn＇t avoid the computational difficulties very well, furthermore, some new problems arose. The concept of optimum constraint sensitivity was proposed, and the quadratic constraints in system level were reformed. Hence, a new collaborative optimization was developed, which is called system level dynamic constraint collaborative optimization （DCCO）. The novel method is able to increase the exchange of information between system level and disciplinary level. The optimization results of each disciplinary optimization can be feedback to system level with the optimum constraint sensitivity. On the basis of the information, the new system level linear dynamic constraints can be constructed; it is better to reflect the effect of disciplinary level optimizations. The system level optimizer can clearly capture the boundary where disciplinary objective functions become zero, and considerably enhance the convergence. Two standard MDO examples were conducted to verify the feasibility and effectiveness of DCCO. The results show that DCCO can save the solving time, and is much better in terms of convergence and robustness, hence, the new method is more effi

关键词： multidisciplinary design optimization (MDO) collaborative optimization (CO) dynamic constraint

System modeling and dynamic analysis of ISG hybrid power shafting

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Journal of Beijing Institute of Technology 2013年第2期22卷 163-170页

作者：周久焱孙逢春程夕明王志福 National engineering Laboratory for electric vehicle Beijing Institute of Technology

A system model is established to analyze the dynamic performance of an integrated starter and generator （ISG） hybrid power shafting. The model couples the electromechanical coupling shaft dynamics, the bearing hydrodynamic lubrication and the engine block stiffness. The model is com- pared with the model based on ADAMS or the model neglecting the bearing hydrodynamics. The bearing eccentricity and the oil film pressure have been calculated under different hybrid conditions or at the different motor power levels. It＇ s found that the bearing hydrodynamics decreases the cal- culation results of the bearing peak load. Changes of the hybrid conditions or the motor power have no significant effect on the main bearing, but have impact on the motor bearing. A hybrid power sys- tem composed of a 1.6 L engine and a 45 kW ISG motor can operate safely.

关键词： system modeling integrated starter and generator (ISG) hybrid power system dy-namic analysis

Rotary ultrasonic-assisted milling of brittle materials

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中国有色金属学会会刊：英文版 2012年第S3期22卷 793-800页

作者： KUO Kei-lin TSAO Chung-chen department of vehicle engineering National Taipei University of Technology department of Automation engineering Tahua Institute of Technology

In order to improve the machining efficiency of ultrasonic milling,the easiest and most effective approach was started with the improvement of tool *** main objective of this research was to utilize rotary ultrasonic machining (RUM's) effectiveness in removing brittle materials to extend the applications of this independent,innovative manufacturing method (self-driving rotary ultrasonic machining),and to experimentally investigate its milling application on brittle *** designed tool was used in the conjunction with previously established RUM machine tools,and glass was selected as workpiece for *** interrelationship between feed rate and depth of cut was *** measuring the surface roughness of workpiece,the overall efficacy of utilizing RUM for milling was evaluated and *** assisted milling results in the reduction of milling resistance,which leads to a greater process rate.

关键词： rotary ultrasonic ultrasonic assisted milling brittle material

High heat flux thermal management through liquid metal driven with electromagnetic induction pump

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Frontiers in Energy 2022年第3期16卷 460-470页

作者： Chuanke Liu Zhizhu He department of vehicle engineering College of EngineeringChina Agricultural UniversityBeijing100083China

In this paper, a novel liquid metal-based minichannel heat dissipation method was developed for cooling electric devices with high heat flux. A high-performance electromagnetic induction pump driven by rotating permanent magnets is designed to achieve a pressure head of 160 kPa and a flow rate of 3.24 L/min, which could enable the liquid metal to remove the waste heat quickly. The liquid metal-based minichannel thermal management system was established and tested experimentally to investigate the pumping capacity and cooling performance. The results show that the liquid metal cooling system can dissipate heat flux up to 242 W/cm2 with keeping the temperature rise of the heat source below 50°C. It could remarkably enhance the cooling performance by increasing the rotating speed of permanent magnets. Moreover, thermal contact resistance has a critical importance for the heat dissipation capacity. The liquid metal thermal grease is introduced to efficiently reduce the thermal contact resistance (a decrease of about 7.77 × 10−3 °C/W). This paper provides a powerful cooling strategy for thermal management of electric devices with large heat power and high heat flux.

关键词： high heat flux liquid metal electromagnetic pump minichannel heat sink thermal interface material

Mode switching control strategy of dual motors coupled driving on electric vehicles

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Journal of Beijing Institute of Technology 2011年第3期20卷 394-398页

作者：张承宁武小花王志福田真 National engineering Laboratory for electric vehicle Beijing Institute of Technology

Based on analyzing the structure and working principle on electric vehicles （EVs） with dual motors coupled by planetarY gears, the control strategy of mode switching was proposed. The power interruption problem on EVs with automatic mechanical transmission （AMT） shifting was resolved. Based on the speed-torque characteristics of the planetary gears and the principle of the auxiliary motor＇ s zero speed braking, control features of mode switching were introduced. The mode shifting between the main motor mode and dual motors coupled driving were studied. Matlab/Simulink was adopted as a platform to develop the simulation model of EVs with dual motors drive system and 3 gears AMT. Simulation results demonstrated that the power interruption of dual motors drive system was solved during mode switching. The power requirements of EVs were satisfied, too.

关键词： dual motors coupled driving mode switching control strategy

Beyond fossil:the synthetic fuel surge for a green-energy resurgence

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Clean Energy 2024年第5期8卷 1-18页

作者： Sreejaun Thothaathiri Janaki Dinesh Kumar Madheswaran G.Naresh Thangavelu Praveenkumar electric vehicle Technology Laboratory Department of Automobile EngineeringSRM Institute of Science and TechnologyKattankulathur CampusTamilnadu 603203India

This review offers a comprehensive overview of synthetic fuels as promising alternatives to conventional fossil *** carbon-neutral potential of synthetic fuels when produced using renewable energy and captured CO_(2),offering significant opportunities to mitigate CO_(2) emissions,is ***,the efficiency of synthetic fuels is presented,as they do not require dedicated agricultural land or substantial water resources,addressing concerns related to the land-use change and water scarcity associated with traditional *** economic viability of synthetic fuels is explored,highlighting the advancements in technology and decreased renewable-energy costs,coupled with their independence from food crops,mitigating concerns about potential impacts on food *** investments by industry leaders such as Porsche,Highly Innovative Fuels Global,and ExxonMobil,totalling$1 billion,aimed at achieving an annual production of 550 million litres by 2026,are covered in *** study is further extended by emphasizing the scalability of synthetic fuel production through modular processes,enabling tailored facilities to meet regional demands and contribute to a decentralized and resilient energy ***,the‘drop-in’nature of synthetic fuels that are seamlessly compatible with existing fuel storage,pipelines,and pumps,facilitating a smooth transition without requiring extensive infrastructure changes,is *** such as the current high cost of synthetic fuel production are acknow-ledged,necessitating supportive government policies and incentives for widespread ***,synthetic fuels have emerged as promising contenders in the pursuit of sustainable and adaptable energy solutions,with tangible benefits for the environment,economy,and existing energy infrastructure.

关键词： synthetic fuels biofuels carbon neutrality sustainable energy e-fuel ‘drop-in’nature

Vibration energy regeneration of electric vehicle shock absorber

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Journal of Beijing Institute of Technology 2013年第3期22卷 337-341页

作者：张军梁新成唐建华 National engineering Laboratory for electric vehicle Beijing Institute of Technology

The twin-tube shock absorber was studied and the relevant factors of thermal equilibrium were simulated. The dynamic model of the shock absorber was constructed and simulation curves of force-displacement and force-velocity were output. The experiment of the twin-tube shock absorber was carried out, and the results were compared with the modeling resultss. Further, the vibration energy regeneration model was established, and the bench simulation study was carried out. The re- sults showed that the energy regeneration model not only absorbed shock energy but also converted vibration energy into electricity energy.

关键词： electric vehicle (EV) vibration energy regeneration shock absorber simulation

Noise reduction method for nonlinear signal based on maximum variance unfolding and its application to fault diagnosis

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Science China(Technological Sciences) 2010年第8期53卷 2122-2128页

作者： ZHANG Yun &LI BenWei department of Airborne vehicle engineering,Naval Aeronautical engineering Institute,Yantai 264001,China department of Airborne vehicle engineering Naval Aeronautical Engineering Institute Yantai China

A new noise reduction method for nonlinear signal based on maximum variance unfolding(MVU)is *** noisy sig- nal is firstly embedded into a high-dimensional phase space based on phase space reconstruction theory,and then the manifold learning algorithm MVU is used to perform nonlinear dimensionality reduction on the data of phase space in order to separate low-dimensional manifold representing the attractor from noise ***,the noise-reduced signal is obtained through reconstructing the low-dimensional *** simulation results of Lorenz system show that the proposed MVU-based noise reduction method outperforms the KPCA-based method and has the advantages of simple parameter estimation and low parameter *** proposed method is applied to fault detection of a vibration signal from rotor-stator of aero engine with slight rubbing *** denoised results show that the slight rubbing features overwhelmed by noise can be effectively extracted by the proposed noise reduction method.

关键词： nonlinear noise reduction manifold learning maximum variance unfolding fault diagnosis