球双锥外形稀薄过渡流区气动特性研究

采用风洞试验和工程计算相结合的方法,对球双锥类外形的稀薄过渡流区气动特性进行了研究。风洞试验在高超声速低密度风洞中进行,设计了高灵敏度的外式微量天平,解决了温度防护和高精度校准的问题,得到了球双锥外形在高度65km~75km、高超声速流动的气动力数据。在此基础上,结合球双锥细长体外形绕流的特点和DSMC数值模拟结果,从连续流粘性干扰模型、关联参数选取、过渡流搭桥函数等三个方面对现有工程计算方法进行了改进。研究结果表明:稀薄效应对球双锥外形的气动特性,尤其是轴向力系数和升阻比产生非常大的影响;计算与试验结果的对比表明,计算模型的改进效果显著,大幅度提高了预测值的准度。

Aerodynamic characteristics of rarefied transitional flow around sphere-bicone configuration

Experiment and engineering approach have been applied to research aerodynamic characteristics of rarefied transitional flow around sphere-bicone configuration. The experiment was conducted in hypersonic low density wind tunnel, a type of high sensitivity external microbalance had been designed, both problems of temperature proof and high accuracy calibration were solved, Aerodynamic data of sphere-bicone configuration had been measured under simulating altitude 65kin -75kin and hypersonic flow conditions. Based on the character of flow around slender sphere-bicone configuration and DSMC numerical computation results, the engineering approach have been improved, including viscous interaction model in continuous flow, selection of correlative parameters and construction of the bridge functions in transitional flow. These studies indicate that the effect of rarefied flow remarkably influenced the aerodynamic characteristics of sphere-bicone configuration, especially axial force coefficient and lift-drag ratio. It has been shown from comparison of experimental and computational results, the new engineering approach developed in this paper has prominently improved the accuracy of predicted data.