风洞模型投放试验轻模型法重力效应影响

风洞模型投放试验是研究超声速机弹分离问题的一种有效手段，相似参数的选取是影响试验准度的关键因素。有初始弹射速度的超声速机弹分离研究中，通常采用"轻模型法"得到模型的运动学及动力学相似参数，但该相似参数中模型重力模拟不足。为了研究重力效应对投放试验结果的影响，采用CTS试验技术对全尺寸真实参数与缩比尺寸轻模型法相似参数条件下得到的结果进行了对比研究。研究结果表明：在载弹与载机分离过程中，载弹位姿相互耦合，垂直下落位移的快慢会影响载弹姿态角的变化；轻模型法相似参数条件下，载弹垂直下落位移较慢，虚拟重力的修正方法只能近似修正下落位移，不能对导弹姿态角进行修正，而姿态角会影响下落的位移；机弹分离安全性方面，轻模型法相似参数条件下的试验结果较真实参数偏危险。

Gravity effects of light model method in wind tunnel model drop-test

Drop-test of the model in the wind tunnel is an effective way to investigate the supersonic store separation issues. The choice of similarity parameters is the key factor that influences the test accuracy. In the study of supersonic store separation with initial ejection velocity, the light model method is usually employed to achieve kinematics and dynamic similarity parameters of the model, but the gravity of the model cannot be accurately modelled. To investigate the effects of gravity on the store release test results, the CTS (Captive Trajectory System) test technique is employed. The test results for full-size actual flight parameters and reduced-size similarity parameters for light model method are compared. Results show that in the release procedure, the missile positions and attitudes are strongly coupled, and the vertical descending velocity would affect the variation of the missile attitudes. Under the similar parameters for the light model method, the descending velocity is relatively slow. The virtual gravity correction method is able to approximately modify the descending displacement, whereas it is not suitable for missile attitude revision. Moreover, the attitudes would affect the descending displacement. In the regime of store release safety, the test results under similar parameters which achieved by the light model method tends to be more riskier than employing the actual flight parameters.