基于化学反应的高超声速弹丸头部气动热预测

为了准确预测高超声速弹丸表面的气动热问题,在考虑热化学反应的情况下,基于SST k-ω、表面反应和二维非稳态热传导方程,建立了高速流场与弹丸结构紧密耦合的传热模型,并以某外形高超声速弹丸为研究对象,采用数值模拟方法,在不同飞行高度、不同飞行马赫数等条件下对比计算了有、无考虑化学反应时弹丸表面的气动热分布情况。计算结果表明,考虑化学反应对弹丸表面的热流密度有较大影响,弹体表面温度及其驻点处温度均有明显提高; 在飞行马赫数为5.5,飞行时间为1.5 s的情况下,随着飞行高度的增加,弹丸驻点处及弹身表面的温度会降低,但各高度上弹丸驻点处的温度在考虑化学反应较未考虑化学反应时高约200 K; 随着来流马赫数的增加,化学反应产生的热量越多,弹体表面及驻点处的温度增加越大。研究结果对高超声速弹丸的气动热预测与热防护具有一定的参考。

Aerothermal Prediction for Nose of Hypersonic ProjectileBased on Chemical Reaction

In order to accurately predict the aero-thermal problems on the surface of hypersonic projectiles,taking into account the thermochemical reaction,a heat transfer model of the high-speed flow field tightly coupled with the projectile structure was established based on the SST k-ω,surface reaction and two-dimensional unsteady heat conduction equation. Taking a certain shape hypersonic projectile as the research object,the numerical simulation method was applied,and the aerodynamic heat distribution of the projectile surface with and without considering the chemical reaction was compared and calculated under the conditions of different flight altitudes,different flight Mach numbers. The result shows that considering the chemical reaction has a great influence on the heat flux density on the surface of the projectile,and the surface temperature of the projectile and the temperature at the stagnation point are significantly increased. When the fight Mach number is 5.5 and the flight time is 1.5 s,the temperature at the stagnation point and the surface of the projectile body will decrease with the increase of the flight height,but the temperature at the stagnation point of the projectile at each height is about 200 K higher than that while the chemical reaction is not considered. With the increase of the incoming Mach number,the more the heat generated by the chemical reaction,the more the temperature of the projectile surface and the stagnation point increases. The research result can offer reference for the aerothermal prediction and thermal protection of hypersonic projectiles.