Chuguang Zheng

Bio: Chuguang Zheng is an academic researcher from Huazhong University of Science and Technology. The author has contributed to research in topics: Bhatnagar–Gross–Krook operator & Computer cooling. The author has an hindex of 3, co-authored 3 publications receiving 2042 citations.

Discrete lattice effects on the forcing term in the lattice Boltzmann method

Abstract: We show that discrete lattice effects must be considered in the introduction of a force into the lattice Boltzmann equation. A representation of the forcing term is then proposed. With the representation, the Navier-Stokes equation is derived from the lattice Boltzmann equation through the Chapman-Enskog expansion. Several other existing force treatments are also examined.

A coupled lattice BGK model for the Boussinesq equations

Abstract: In this paper, a thermal lattice BGK model is developed for the Boussinesq incompressible fluids. The basic idea is to solve the velocity field and the temperature field using two independent lattice BGK equations, respectively, and then combine them into one coupled model for the whole system. The porous plate problem and the two-dimensional natural convection flow in a square cavity with Pr=0.71 and various of Rayleigh numbers are simulated using the model. The numerical results are found to be in good agreement with the analytical solutions or those of previous studies. Copyright © 2002 John Wiley & Sons, Ltd.

An extended Navier-Stokes formulation for gas flows in the Knudsen layer near a wall

Abstract: Gas flows in the Knudsen layer adjacent to a solid wall cannot be described by the classical Navier-Stokes constitution in general, and high-order models such as the Burnett and super-Burnett models encounter many difficulties in practical applications. In the present work we propose an extended Navier-Stokes constitution in which the effect of the collisions between the gas molecules and bounded walls is incorporated. With this model, it is found that the flow behaviors in the Knudsen layer can be effectively captured.

Non-circulating liquid cooling structure for short-time high-power heat generation stage of motor

Abstract: In order to solve the problem of large motor temperature rise caused by short-time high-power heat generation in the vertical take-off and landing phase of electric aircraft that can take off and land vertically, this paper uses a closed non circulating liquid cooling structure to make the water with high specific heat capacity absorb a large amount of heat, alleviate the motor temperature rise in this phase, and then improve the motor efficiency. In this paper, the number of fins, height ratio, fin section shape and other parameters in this structure are optimized based on simulation, so as to reduce the water weight required to achieve the thermal management objectives as much as possible; Through the simulation data, some relations between the structural parameters and the heat storage effect are obtained. Finally, 441g of water is used to meet the casing temperature control target of 2.5kW continuous heat generation for 1min.

Kinetic theory representation of hydrodynamics: a way beyond the Navier–Stokes equation

Abstract: We present in detail a theoretical framework for representing hydrodynamic systems through a systematic discretization of the Boltzmann kinetic equation. The work is an extension of a previously proposed formulation. Conventional lattice Boltzmann models can be shown to be directly derivable from this systematic approach. Furthermore, we provide here a clear and rigorous procedure for obtaining higher-order approximations to the continuum Boltzmann equation. The resulting macroscopic moment equations at each level of the systematic discretization give rise to the Navier–Stokes hydrodynamics and those beyond. In addition, theoretical indications to the order of accuracy requirements are given for each discrete approximation, for thermohydrodynamic systems, and for fluid systems involving long-range interactions. All these are important for complex and micro-scale flows and are missing in the conventional Navier–Stokes order descriptions. The resulting discrete Boltzmann models are based on a kinetic representation of the fluid dynamics, hence the drawbacks in conventional higher-order hydrodynamic formulations can be avoided.