气动塞式喷管底部二次流特性的数值模拟

Numerical analysis of base bleed effect on aerospike nozzle performance

关键词:  塞式喷管  喷管气流  流动分布  二次流  数值模拟

Key words:  Plug nozzle  Nozzle flow  Flow distribution  Secondary flow  Numerical simulati?

摘要:

发展了一套可以对底部有二次流的气动塞式喷管的性能进行预示的数值方法 ,采用二阶精度的NND格式求解二维层流N S方程 ,对底部二次流的入口边界条件进行了特殊处理。以一种实验用的直排式气动塞式喷管为对象 ,针对两种不同的背压条件 ,对二次流流量分别为主流的 0 % ,1% ,3%和 5 %的几种工况研究了塞式喷管底部二次流流量变化对喷管性能影响。计算结果表明 ,底部二次流的加入使得气动塞式喷管性能有比较明显的提高。数值方法可以用于气动塞式喷管的设计和性能预报。

Abstract:

A simplified numerical model was developed to predict the base bleed effect on aerospike nozzle performance.Second order NND scheme was used to solve two dimensional Navier Stokes equations under laminar assumption.A special treatment to the inlet boundary condition of base bleed was put forward to simplified the complex inlet flow.This simple numerical model was implemented to compute an experimental linear aerospike nozzle at two different ambient pressure and with four different base bleed discharge.The results show that base bleed significantly increases the nozzle base pressure and nozzle thrust increases with the increasing of base bleed discharge.