针对发动机羽流的相似准则研究

Investigation on Similarity Criterion for Engine Plume

限于真空设备的能力,地面上难以开展大发动机的羽流试验,此时需要借助缩尺技术方可开展试验。通过方程分析法和量纲分析法推导出一种适用于发动机流场的相似准则,该准则能够使流场所有参数满足相似关系,这对于开展试验研究复杂的羽流现象有很大帮助。随后以热对流现象为研究目标,从理论角度对相似准则进行了验证。最后借助CFD/DSMC方法对发动机羽流全流域进行了数值模拟,进一步验证了相似准则的正确性和在羽流研究中的适用性。

Due to the limited capability of the vacuum equipment,it is difficult to carry out a vacu-um plume experiment on the ground for a large thrust engine.Hence scaling technique is needed to solve this problem.A new similarity criterion was derived in this paper by employing the formulation analysis and dimensionless analysis methods.The new criterion,which could make two flow fields strictly similar,was helpful for the experimental study of complex phenomena influenced by all pa-rameters of the plume field.The criterion was validated theoretically by studying the thermo-convec-tion.In the end,simulations of the engine plume fields were performed to validate the criterion by using the coupled CFD/DSMC(Computational Fluid Dynamics/Direct Simulation of Monte Carlo)method,and the result showed that the criterion was correct and could be used in the research of en-gine plume.