The Experts below are selected from a list of 7557 Experts worldwide ranked by ideXlab platform
Jiuxing Zhang - One of the best experts on this subject based on the ideXlab platform.
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Thermal-Fluid-structure coupling analysis for valve plate friction pair of axial piston pump in electrohydrostatic actuator (EHA) of aircraft
Applied Mathematical Modelling, 2017Co-Authors: Y.x. Li, Liman Yang, Zhanling Ji, Bing Xu, Peng Zhang, Jiuxing ZhangAbstract:This paper deals with Thermal-Fluid-structure coupling analysis for valve plate friction pair of axial piston pump in electrohydrostatic actuator (EHA) of aircraft. The axial piston pump with high pressure and high rotational speed to be widely applied in EHA of more electric aircraft can increase the power density, but it also deteriorates Thermal-Fluid-structure coupling of the friction pairs. In order to reveal its interior multiphysics field coupling mechanism, taking the valve plate friction pair in three key friction pairs for example, this study carries out the research on multiphysics field coupling. Firstly, Navier–Stokes equations and energy equation of the incompressible Fluid considering the influence of temperature and pressure on the oil properties, heat conduction governing equation with many boundary conditions including heat flux, heat convection, heat radiation and considering the influence of the structure deformation on the temperature and the influence of the temperature on the material properties, the elastic mechanics model of the structure exerted together by temperature, Fluid pressure and mechanical load, are established. On this basis, a complete set of fast and effective Thermal-Fluid-structure coupling method is originally presented, and the numerical analysis is conducted using it for the valve plate friction pair. By the calculation results, the evolution laws with time and space are revealed regarding to the pressure and temperature of the Fluid in the chambers, and the temperature, stress and deformation of the valve plate friction pair, the wedge-shaped clearance forms between them, even mixed friction occurs, and the corresponding improving measures aimed at the discovered problems are discussed. These results can provide the theoretical evidence for the design and development of the pump of EHA.
Zhanling Ji - One of the best experts on this subject based on the ideXlab platform.
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Research on Thermal-Fluid-structure coupling of valve plate pair in an axial piston pump with high pressure and high speed
Industrial Lubrication and Tribology, 2018Co-Authors: Zhanling JiAbstract:Purpose High pressure and high speed of the axial piston pump can improve its power density, but they also deteriorate the Thermal-Fluid-structure coupling effect of the friction pairs. This paper aims to reveal the coupling mechanism of the pump, for example, valve plate pair, by carrying out research on multi-physics field coupling. Design/methodology/approach Considering the influences of temperature on material properties and Thermal Fluid on structure, the Thermal-Fluid elastic mechanics model is established. A complete set of fast and effective Thermal-Fluid-structure coupling method is presented, by which the numerical analysis is conducted for the valve plate pair. Findings According to calculations, it is revealed that the temperature and pressure evolution laws of oil film with time, the pressure distribution law of the Fluid, stress and displacement distribution laws of the solid in the valve plate pair. In addition, the forming history of the wedge-shaped oil film and mating clearance change law with rotational speed and outlet pressure in the valve plate pair are presented. Originality/value For an axial piston pump operating under high speed, high pressure and wide temperature range, the multi-physics field coupling analysis is an indispensable means and method. This paper provides theoretical evidence for the development of the pump and lays a solid foundation for the research of the same kind of problem.
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Thermal-Fluid-structure coupling analysis for valve plate friction pair of axial piston pump in electrohydrostatic actuator (EHA) of aircraft
Applied Mathematical Modelling, 2017Co-Authors: Y.x. Li, Liman Yang, Zhanling Ji, Bing Xu, Peng Zhang, Jiuxing ZhangAbstract:This paper deals with Thermal-Fluid-structure coupling analysis for valve plate friction pair of axial piston pump in electrohydrostatic actuator (EHA) of aircraft. The axial piston pump with high pressure and high rotational speed to be widely applied in EHA of more electric aircraft can increase the power density, but it also deteriorates Thermal-Fluid-structure coupling of the friction pairs. In order to reveal its interior multiphysics field coupling mechanism, taking the valve plate friction pair in three key friction pairs for example, this study carries out the research on multiphysics field coupling. Firstly, Navier–Stokes equations and energy equation of the incompressible Fluid considering the influence of temperature and pressure on the oil properties, heat conduction governing equation with many boundary conditions including heat flux, heat convection, heat radiation and considering the influence of the structure deformation on the temperature and the influence of the temperature on the material properties, the elastic mechanics model of the structure exerted together by temperature, Fluid pressure and mechanical load, are established. On this basis, a complete set of fast and effective Thermal-Fluid-structure coupling method is originally presented, and the numerical analysis is conducted using it for the valve plate friction pair. By the calculation results, the evolution laws with time and space are revealed regarding to the pressure and temperature of the Fluid in the chambers, and the temperature, stress and deformation of the valve plate friction pair, the wedge-shaped clearance forms between them, even mixed friction occurs, and the corresponding improving measures aimed at the discovered problems are discussed. These results can provide the theoretical evidence for the design and development of the pump of EHA.
P. Birken - One of the best experts on this subject based on the ideXlab platform.
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Extrapolation in Time in Thermal Fluid Structure Interaction
Lecture Notes in Computational Science and Engineering, 2020Co-Authors: P. Birken, T. Gleim, Detlef Kuhl, Andreas MeisterAbstract:We consider time dependent Thermal Fluid structure interaction. The respective models are the compressible Navier-Stokes equations and the nonlinear heat equation. A partitioned coupling approach via a Dirichlet-Neumann method and a fixed point iteration is employed. As a reference solver a previously developed efficient time adaptive higher order time integration scheme is used. To improve upon this, we work on reducing the number of fixed point coupling iterations. Thus, we explore the idea of extrapolation based on data given from the time integration and derive such methods for SDIRK2. This allows to reduce the number of fixed point iterations further by up to a factor of two with linear extrapolation performing better than quadratic.
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Fast solvers for Thermal Fluid structure interaction
2020Co-Authors: P. Birken, T. Gleim, Detlef Kuhl, Andreas MeisterAbstract:We consider Thermal Fluid structure interaction to model industrial gas quenching in steel forging, where hot steel Is cooled using cold high pressured gas. This allows to define properties of the finished steel part, as for example yield strength, locally at low cost and without environmental problems. For the numerical simulation, a partitioned approach via a Dirichlet-Neumann coupling and a fixed point iteration is employed. In time, previously developede fficient time adaptive higher order time integration schemes are used. The respective models are the compressible Navier-Stokes equations and the nonlinear heate quation, where the parameter functions are obtained from measurements on a specific steel. Here, the use of different vector extrapolation methods for convergence acceleration techniques of the fixed point iteration is analyzed. Inparticular, Aitkenrelaxation, mini-malpolynomial extrapolation (MPE) and reduced rank extrapolation (RRE) are consid-ered. (Less)
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Numerical methods for unsteady Thermal Fluid structure interaction
Fluid-Structure Interaction, 2017Co-Authors: P. Birken, Azahar MongeAbstract:We discuss Thermal Fluid-structure interaction processes, where a simulation of the time-dependent temperature field is of interest. Thereby, we consider partitioned coupling schemes with a Dirichlet-Neumann method. We present an analysis of the method on a model problem of discretized coupled linear heat equations. This shows that for large quotients in the heat conductivities, the convergence rate will be very small. The time dependencymakes the use of time-adaptive implicitmethods imperative. This gives rise to the question as to how accurately the appearing nonlinear systems should be solved, which is discussed in detail for both the nonlinear and linear case. The efficiency of the resulting method is demonstrated using realistic test cases. (Less)
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Experimental and numerical aspects of a Thermal Fluid-structure phenomenon
AIP Conference Proceedings, 2017Co-Authors: T. Gleim, P. Birken, Dietmar Kuhl, Mackenzie Weiland, Armin Meister, Olaf WünschAbstract:© 2017 Author(s). A fundamental research experiment for Thermal Fluid-structure-interaction for the verification of a partitioned approach with non-linear material properties is examined. In the following, a specimen is heated as well as cooled within a wind tunnel. The Thermal Fluid-structure-interaction is first experimentally investigated and subsequently numerically validated. For the numerical simulation, two existing programs (a Fluid and a structure code) are coupled using a partitioned approach.
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Thermal Fluid-structure-interaction - Experimental and numerical analysis
AIP Conference Proceedings, 2015Co-Authors: T. Gleim, P. Birken, Dietmar Kuhl, Mackenzie Weiland, Armin Meister, Olaf WünschAbstract:© 2015 AIP Publishing LLC. In the present paper the Thermal Fluid-structure-interaction is experimentally and numerically investigated. There-fore, the interaction phenomena is modeled by the Reynolds-averaged Navier-Stokes equations and the nonlinear Fourier heat conduction equation are used for the Fluid and the solid phase, respectively. The simulation is performed using a partitioned approach using the finite volume method for the Fluid domain, the finite element method for the solid domain and Runge-Kutta integration schemes for the time domain. Furthermore, as a basis for the understanding of Thermal Fluid-structure-interaction and also for the verification and validation of the applied continuum mechanical models and numerical methods, respectively, a fundamental wind tunnel experiment is presented.
Y.x. Li - One of the best experts on this subject based on the ideXlab platform.
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Thermal-Fluid-structure coupling analysis for valve plate friction pair of axial piston pump in electrohydrostatic actuator (EHA) of aircraft
Applied Mathematical Modelling, 2017Co-Authors: Y.x. Li, Liman Yang, Zhanling Ji, Bing Xu, Peng Zhang, Jiuxing ZhangAbstract:This paper deals with Thermal-Fluid-structure coupling analysis for valve plate friction pair of axial piston pump in electrohydrostatic actuator (EHA) of aircraft. The axial piston pump with high pressure and high rotational speed to be widely applied in EHA of more electric aircraft can increase the power density, but it also deteriorates Thermal-Fluid-structure coupling of the friction pairs. In order to reveal its interior multiphysics field coupling mechanism, taking the valve plate friction pair in three key friction pairs for example, this study carries out the research on multiphysics field coupling. Firstly, Navier–Stokes equations and energy equation of the incompressible Fluid considering the influence of temperature and pressure on the oil properties, heat conduction governing equation with many boundary conditions including heat flux, heat convection, heat radiation and considering the influence of the structure deformation on the temperature and the influence of the temperature on the material properties, the elastic mechanics model of the structure exerted together by temperature, Fluid pressure and mechanical load, are established. On this basis, a complete set of fast and effective Thermal-Fluid-structure coupling method is originally presented, and the numerical analysis is conducted using it for the valve plate friction pair. By the calculation results, the evolution laws with time and space are revealed regarding to the pressure and temperature of the Fluid in the chambers, and the temperature, stress and deformation of the valve plate friction pair, the wedge-shaped clearance forms between them, even mixed friction occurs, and the corresponding improving measures aimed at the discovered problems are discussed. These results can provide the theoretical evidence for the design and development of the pump of EHA.
Yujia Gong - One of the best experts on this subject based on the ideXlab platform.
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Optimum Methods of Thermal-Fluid Numerical Simulation for Switchgear
IEEE Access, 2019Co-Authors: Jiangjun Ruan, Yongcong Wu, Peng Li, Mingyang Long, Yujia GongAbstract:Thermal-Fluid coupled calculation is an effective way to simulate the temperature rise and heat dissipation process of switchgear. But there are still problems such as huge calculation and low accuracy need to be solved. This paper discusses the optimization methods of the Thermal-Fluid coupled field for the switchgear from grid controlling, boundary conditions, and heat source calculation. First, the mesh adaption method based on posterior error estimation is proposed to achieve efficient mesh refinement with less redundancy. The final mesh size is only 32.3% of that obtained with the traditional global-refining method. Then, an external flow model is built to obtain the convective heat transfer coefficient of the enclosure, replacing the process of artificial choosing. The results show that the convective heat transfer coefficient at the enclosure under natural convection is 0.4 W/(m2 ·°C) ~1.4 W/(m2·°C). Afterwards the eddy current field is used to solve the heat generation in the switchgear. The heat sources are coupled to the Thermal-Fluid calculation so that the influence of current non-uniformity, contact heat, and eddy loss is considered. At last, the methods are applied to the steady-state temperature rise simulation of KYN28A-12kV/630A switchgear and the results are compared with the test data. The maximum relative error between simulation and experimental results is 3.43%, which proves the validity of the mentioned methods.
