基于Fluent的底部排气弹减阻特性数值模拟

Numerical Simulation of Drag Reduction Characteristics of Base Bleed Projectile Based on Fluent

运用前处理软件Gambit建立模型,运用Fluent软件进行了仿真计算,研究了弹丸在有无底排状况下的流场特性,分析了不同马赫数以及不同攻角飞行状态下弹丸的阻力系数和升力系数的变化规律。结果表明:在超音速来流下,阻力系数随来流攻角的增大呈抛物线性增大,随来流马赫数的增大呈抛物线性减小,升力系数随来流攻角的增大呈线性增大,随来流马赫数的增大而减小,且攻角越大减小幅度越明显;弹丸在有无底排前后,升力系数无明显变化,阻力系数大幅下降,最高减阻率达34.8%。

The pre-processing software Gambit was used to establish the model and mesh it,and the simulation calculation was carried out by Fluent software.The flow field characteristics of projectile with or without base bleed were studied,the variation laws of drag coefficient and lift coefficient of projectile under different mach number and different angle of attack flight were analyzed.The results show that the drag coefficient increases parabolically with the increase of attack angle and decreases parabolically with the increase of mach number under the supersonic flow,and the lift coefficient increases linearly with the increase of attack angle,decreases with the increase of mach number,and decreases more obviously with the increase of attack angle;The lift coefficient of projectile has no obvious change before and after the base bleed,the drag coefficient decreases sharply,and the maximum drag reduction rate of the drag coefficient reaches 34.8%.