无控飞行弹箭气动加热特性

摘要

针对无控飞行弹箭动态红外特征的数值计算问题,提出了一种计算其表面气动加热的数值方法.建立了155 mm口径无控炮弹的六自由度刚体弹道仿真模型;取目标在亚声速、跨声速、超声速飞行状态下的弹道数据为来流条件,基于 FLUENT进行了外流场数值模拟;分析了弹体表面压力、温度分布及驻点热流密度的变化规律,并与经验公式的计算结果进行了对比验证.结果表明,随着弹头曲率半径减小,驻点热流密度呈非线性增加趋势,马赫数越高,弹体表面的峰值压力和温度越高,且温度变化梯度越大;高温区集中于弹头及弹头部与圆柱部交接处,低温区分布在弹体尾部和底部,数值模拟与经验公式的计算值吻合较好.%According to the numerical calculation of dynamic infrared characteristics of uncontrolled flying pro-j ectile,a numerical method for calculating the surface aerodynamic heating was proposed.Firstly,a 6-DOF trajectory simulation model of 155mm caliber uncontrolled projectile was established.Secondly,trajectory data of projectile in subsonic,transonic and supersonic flight states were used as the flow condition,and the outflow field was simulated by FLUENT software.Finally,the variation of surface pressure,temperature distribution and stagnation heat flux density of the proj ectile body are analyzed and compared with the calculation results of the empirical formula.The results demonstrated that the smaller the curvature radius of warhead,the greater the stagnation heat flux and non-linearly increasing;The higher the Maher number was,the higher the peak pressure and temperature on the surface of the projectile were,and the greater the gradient of temperature varia-tion was.The high temperature area was concentrated on the warhead,and the j unction of warhead and cylinder portion;On the contrary,the low temperature area was located on the rear and base of the projectile.It was dis-covered from the results of simulation and the empirical resolution shows a good agreement.