中文摘要：

基于单元格压力线形假设，提出了一种处理微流道压力边界的新方法．将此方法应用于直接蒙特卡罗（DSMC）方法，分别对在4种压力边界条件下的微流道气体流场进行了数值模拟，获得了微尺度流场的速度分布及压力分布，并比较了在各种压力边界条件下微流场的稀薄特性和沿程压力的线性度分布．研究表明，采用此方法获得的速度和压力模拟解与解析解比较一致；在整体更为稀薄的微流场中，由此方法给出的沿程压力分布线性度更好，Knudsen数变化更大．进出口速度收敛性分析表明，此方法不仅具有稳定的收敛性，而且与现有方法相比收敛更快．

英文摘要：

Based on the assumption of linear pressure distribution in the cells, a new method tO deal with the pressure boundary of the flow in micro-channel was proposed. The method was applied in the numerical simulation for the gas flows in micro-channel with four different pressure boundary conditions by direct simulation Monte Carlo （DSMC） method. The distributions of velocity and local pressure were presented, and the rarefied effect and the linear drop of the local pressure along the micro-channel with the different boundary conditions were analyzed. The results showed that the simulation solutions of velocity and local pressure were consistent with the slip analytical ones. As the rarefied degree increases, the pressure distri- bution along the micro-channel becomes linear and the variation of Knudsen increases. Furthermore, comparisons of the inlet and outlet velocities with different boundary treatments show that the new method is convergent steadily and can converge faster than previous methods.