应用阻力系数拟合曲线解析式数值解算外弹道诸元

Calculation of Exterior Ballistic Data by Drag Coefficient Curve Fitting

为了研究工程解算弹丸外弹道诸元精度,采用FLUENT软件对某尾翼弹外流场空气动力特性进行数值模拟,得到不同马赫数下的零升阻力系数;利用Origin Lab软件对其进行分段拟合,得到阻力系数拟合曲线解析函数表达式,代入外弹道质心运动微分方程组数值解算外弹道诸元;并与用经典空气阻力定律及相应的平均弹形系数方法解算的外弹道诸元对比。两种方法解算所得弹道落点诸元相对误差在4.61%以内,全弹道上诸元相对误差在6.65%以内。因此,即使能够得出特定弹丸的全弹道阻力系数解析函数表达式,但在工程应用上也可以继续应用简便的经典空气阻力定律及相应的平均弹形系数方法解算外弹道诸元。

In order to research engineering calculation accuracy of projectiles’ exterior ballistic data,aerodynamic characteristics of some fin-stabilized projectile were simulated by FLUENT and the zero-lift drag coefficients of the projectile were acquired. They were piecewise fit by Origin Lab to acquire the algebraic expression of the drag coefficient fitting curve,which was put in the exterior ballistic centroid movement differential equation for exterior ballistic data calculation. The result of method above was compared with that of classic coefficient of projectile form method. The error between data of trajectory was within 4. 61% and the error between the whole exterior ballistic data acquired by both methods above was within 6. 65%. The results indicate that even if the drag coefficient algebraic expression of the whole exterior ballistic could be acquired,the classic coefficient of projectile form method can also be used to calculate the exterior ballistic data of fin-stabilized projectiles in engineering application.