两种约束构形对激光推力器推进性能的影响

Influence of Two Kinds of Restriction Structures on the Propulsion Performance of Laser Thruster

针对大气吸气模式环聚焦喷管无推力壁的激光推力器模型,首次提出对其内部等离子体流场进行约束,给出绕流约束和平行约束2种构形;使用高分辨率的差分方法,结合分区计算,在来流马赫数为5的条件下,分别模拟了基本构形和约束构形的定常流场,以及激光诱导的高温等离子体流场的波系演化过程,计算和比较了推力和冲量耦合系数;基本构形流场的演化规律以及冲量耦合系数的计算结果与文献吻合得很好,结果表明:喷管无推力壁时,绕流约束和平行约束对于推进性能影响不很明显,需设计新的约束构形并验证.

An idea of restricting the plasma flow field produced by a laser focusing on a circular line to the range of interior boundary is put forward for the first time. A second order accurate scheme based on structural grid and domain decomposition is used to compute the detailed laser-induced high temperature flow field both of a laser thruster model and inside interior boundary of restriction for a free-stream mach number equal to five. And the thrust change dependent of time and impulse coupling coefficients are determined to compare the performance of the laser thruster without and with restriction. Results show that the laser thruster with restriction provides a little better performance.