基于FLUENT软件和内弹道模型双向耦合的超高射频火炮发射过程模拟

弹头阻力计算的准确性直接决定了超高射频火炮内弹道数值模拟的准确性。为了提高超高射频火炮内弹道过程数值模拟的准确性，利用二次开发工具UDF将FLUENT软件和经典内弹道（CIB）模型双向耦合计算超高射频火炮弹前流场，得到了超高射频火炮发射过程中第2发弹丸的弹头阻力，分析了不同射击频率下弹头阻力的变化规律。结果表明：FLUENT-CIB模型双向耦合计算能够得到弹前身管内火药气体各个时刻的流场分布，提高了弹头阻力计算的准确性；弹头阻力在弹丸启动后很快由减小变成增大，增大到某个极大值后又逐渐减小，直到弹丸出炮口，这个变化规律在不同射击频率下普遍存在；射频降低，在弹丸运动前期弹头阻力增幅减小，在弹丸运动后期弹头阻力降幅也减小。弹头阻力计算的准确性直接决定了超高射频火炮内弹道数值模拟的准确性。为了提高超高射频火炮内弹道过程数值模拟的准确性，利用二次开发工具UDF将FLUENT软件和经典内弹道（CIB）模型双向耦合计算超高射频火炮弹前流场，得到了超高射频火炮发射过程中第2发弹丸的弹头阻力，分析了不同射击频率下弹头阻力的变化规律。结果表明：FLUENT-CIB模型双向耦合计算能够得到弹前身管内火药气体各个时刻的流场分布，提高了弹头阻力计算的准确性；弹头阻力在弹丸启动后很快由减小变成增大，增大到某个极大值后又逐渐减小，直到弹丸出炮口，这个变化规律在不同射击频率下普遍存在；射频降低，在弹丸运动前期弹头阻力增幅减小，在弹丸运动后期弹头阻力降幅也减小。

Simulation for Launch Process of Ultrahigh Firing Rate Guns Based on Two-way Coupling of FLUENT and Interior Ballistic Model

The numerical simulation accuracy of interior ballistics of ultrahigh firing rate guns depends on the accuracy of calculating the drag force acting on projectile nose. In order to improve the numerical simulation accuracy of interior ballistics of ultrahigh firing rate gun, the secondary development tool UDF is used to couple FLUENT and the classic interior ballistic (CIB) model for the calculation of flow field in front of projectile. The nose drag force of the second launched projectile is obtained, and the variation law of nose drag force at different firing rates is analyzed. The simulated results show that the propellant gas flow field distribution can be obtained by the two-way coupling of FLUENT and CIB model, and the accuracy of calculating the nose drag force is improved. The nose drag force increases quickly after launching, and then decreases after it reaches a maximum value until the projectile leaves the muzzle. This variation law is common at different firing rates. When the firing rate reduces, the increased amplitude of nose drag force decreases at the earlier stage of projectile movement, and its decreased amplitude also decreases at the later stage of projectile movement.