微喷管内气体流动的三维数值模拟

3-D numerical simulation of gas flow in micronozzles

微尺度流体的流动仿真分析是微喷管优化设计的基础。采用Navier-Stokes理论对采用微机电系统技术制作的微喷管中的气体流动进行了三维数值分析,建立了微喷管流动的三维数学模型,给出了该模型的求解算法。对不同燃烧室压强和温度下的微喷管内气体流动的计算结果进行了分析,并与二维计算结果进行了比较。结果表明:微喷管内的流动状态没有因压强和温度的变化而发生根本性的改变;在微尺度下,由于附面层效应,采用二维数值计算将高估微喷管的性能。

Gas flow in a micronozzle was studied to improve the flow rate in the nozzle. The gas flow in MEMS-based micronozzles was numerically analyzed by solving the 3-D Navier-Stokes equations in the micronozzle geometry. The flow was simulated for various pressures and temperatures in the combustion chamber. The results show that pressure and temperature variations in the combustion chamber have no significant effect on the flow field. The result also shows that the boundary layer has an important effect on the gas flow in the micronozzle and that the 2-D simulation overestimates the micronozzle flow rate.