Low-Pressure Three-Dimensional Continuum Flow Simulation in Turbo Vacuum Pumps

渦輪眞空幫浦之低壓三維連續流分析

10.6124/TAASRC.200003_32(1).05

鄭鴻斌(H.-P. Cheng)；崔燕勇(Y.-Y. Tsui)

真空 ； 幫浦 ； 計算流體力學 ； Vacuum ； Pump ； CFD

中國航空太空學會學刊

32卷1期（2000 / 03 / 01）

49 - 55

英文

在這篇文章中使用UNIC軟體分析渦輪真空幫浦的內部流場，流場由於低壓屬於滑流或連續串的甘層流。整個數學模式針對連續方程式及N-S方程式在旋轉座標上進行求解，使用有限插分法進行方程式的離散，並使用body-fitted的格點結構。在對流项上使用三階上風TVD插分法，擴散項及源項使用中央插分法。使用預测／修正的解題步驟來處理相關聯的速度及壓力項，並利用質量守恆來增進收斂的速度。使用implicit Euler time marching方法來增進穩態的收斂速度。在本篇論文中探討了三種不同型式的渦輪真空幫浦，包括有離心式Siegbahn分子拖曳式幫浦、軸流式的Holweck分子拖曳式幫浦以及一種結合了渦輪葉片型式及Holweck型式的混流式幫浦。由計算結果得知計算流體力學可以成功的應用在渦輪真空幫浦的氣流分析上，由計算所得的幫浦內部流場及壓力場可以提供給幫浦設計者，作爲改善幫浦性能的參考。

The UNIC code [1, 2, 3] is adopted to study the f1ow field in turbo vacuum pumps in the slip and continuum f1ow regimes. The mathematical model is set on a rotating frame of reference. Discretization of equations is performed on body-fitted curvilinear mesh systems. A third-order upwind TVD (Total Variation Diminishing) scheme is used for approximating the convective terms of the transport equations while the viscous terms are approximated by the central difference. To deal with the coupling between pressure and velocity a pressure-based predictor/corrector solution procedure is employed. An implicit Euler time marching scheme is used to advance calculation until steady state is reached. Three types of turbo vacuum pumps, that is, radial type of Siegbahn molecular drag pump, the axial type of Holweck molecular drag pump, and a compound turbo booster pump combining the turbo blade pump and the Holweck pump are investigated in this work. The results show that the CFD methodology can be successfully applied to the simulation of the. Pumps Detailed velocity and pressure fields obtained can help to improve design of new types of pump.