微尺度拉伐尔喷管冷态流场及其推进性能

Cold flow field and propulsive performance of a micro Laval nozzle

关键词:  微喷管+  推进性能+  冷流  流动分布  光刻  深度  数值分析

Key words:  Micro-nozzle~+  Propulsive performance~+  Cold flow  Flow distribution  Photolithography  Depth  Numerical analysis

摘要:

为了研究微尺度超声速喷管的推进性能,采用无滑移的连续介质模型,对二维和三维微尺度拉伐尔喷管的冷态流场进行数值模拟。对不同算例的模拟结果进行比较,给出二维微喷管对几何结构和工作条件的要求,结果表明,在绝大部分工作条件下,20°扩张角是较好的外形设计选择;对三维和二维模拟结果进行比较,给出二维微喷管对蚀刻深度的要求,结果表明,蚀刻深度和喷管喉部宽度的比值超过10时,微喷管具备很好的二维特性。

Abstract:

To study the propulsive performance of the supersonic micro Laval nozzle, the 2D and 3D models were presented to simulate the nozzle flow, which were based on the continuum assumption with no-slip boundary conditions. By analyzing the numerical results, the criterion for micro-nozzle design was provided with consideration of nozzle geometry and its working conditions. As a result, the 20° nozzle performs the best over the full range. With the comparison of 2D and 3D numerical results, the rule for determination of the etch depth of 2D micro-nozzle was recommended. The result shows that, the micro-nozzle with the ratio of the etch depth to the throat width in excess of 10, has a good 2D characteristic.