Research on Numerical Simulation of a Sort of Typical Flow System

At present, with the rapid development of Micro-electromechanical Systems(MEMS), micro devices are favored because of their low-cost and excellent performance. The research on the flow and heat transfer has become more and more active in micro motor and micro bearing often met in MEMS. For the micro-scale flow in MEMS, on the one hand, it is difficult to carry through thermal measure and physical experiment for the small frame size. On the other hand, the programs of Burnett Equation and Direct simulation of Monte Carlo (DSMC)approach are trivial and large with high calculating cost. The flow region with higher Knudsen(Kn) number does not belong to continuum flow region, and it can not be solved directly by using N-S Equation. Aiming at micro-scale Couette flow system, the corresponding theoretical model has been built on the basis of improved N-S Equation, Fourier´s law and ideal gas law. Generalized molecule mean free path, generalized dynamic viscosity and generalized heat conductivity are introduced in the new model so it can be used to simulate the flow in the slipping and transition region. Then a new kind of numerical simulation method named the Generalized Differential Quadrature(GDQ) is mainly explored. Applying GDQ method, the numerical simulation of flow field is made. And using DSMC approach, the new model is verified. The solutions show that the simulation results of the new model are basically consistent with the DSMC´s. The remarkable merits of GDQ method consist in its simple program, low calculation cost and large engineering application value. But the error is becoming more and more large with the increase of Kn number. So it is necessary to improve the new model in the later research to simulate the gas flow in the larger domain.