超声速弹箭阻力系数随高度变化的计算方法研究

Calculation method of projectile drag coefficient variation versus altitude

基于气体分子动力学的理论分析了不同飞行高度下弹箭气动力的计算模型及工程计算方法,通过计算和分析不同高度下阻力系数的变化量及其对弹箭射程的影响,得出30 km以下阻力系数随高度的变化是射程主要影响因素的结论。基于参考焓方法分析了30 km以下不同来流参数对阻力系数的影响,将不同来流温度对边界层影响的计算问题转化为同一来流温度不同来流密度下的边界层计算问题,从而简化了影响阻力系数的来流参数,并得到了一个阻力系数随高度变化的实用计算方法,可用于计算阻力系数随高度变化对超远程弹箭射程的影响。

Aiming at calculating drag coefficient variation versus altitude, the numerical and engineering aerodynamic calculation method for different altitude was analyzed. By calculating and analyzing the variation of drag coefficient versus altitude and its effect on the range of trajectory, the conclusion was drawn that the variation of drag coefficient less than 30 km affects the range primarily. Based on the reference enthalpy method, the influence of coming parameter on drag coefficient less than 30 km was analyzed, and the influence of coming temperature on boundary layer was converted to the in-fluence of coming air density and the parameters affecting the drag coefficient were simplified. At last, a practical calculation method was presented for calculating drag coefficient variation versus altitude.