固体发动机环形塞式喷管外流干扰的数值模拟

Numerical Simulation of Outflow Effect on Toroidal Aerospike Nozzle in Solid Propellant Engine

针对外流参数对固体塞式喷管发动机性能的影响,基于防空导弹外形,设计了环喉型塞式喷管结构,建立了包含外流场的三维数值仿真模型,开展了3个工作高度下不同来流马赫数和来流迎角的模拟计算。结果表明:在一定的飞行高度下,外流对塞式喷管尾流产生压缩作用,主要造成导弹底部阻力增大,塞锥壁面压强降低。低空下,来流马赫数越大,喷管性能损失越大。来流迎角对塞式喷管性能的影响程度较小,损失不超过1%。对比锥形喷管,环形塞式喷管在从地面到高空的飞行高度范围内,整体效率都保持了较高的数值,尤其是地面工况的喷管效率可提高约5%。

The effects of outflow in flow field on performance of a missile with toroidal aerospike nozzle during flight under typical Mach numbers and attack angles are studied in this paper.The structure parameters of a toroidal aerospike nozzle engine with ring throat and the missile body shape are designed.The three-dimensional simulation model including free steam flow field is established,and the finite volume method is adopted to make outflow effect on toroidal aerospike nozzle at different heights using FLUENT 15 software.It is shown that the outflows wake the nozzle expansion jet with compression effect,increase missile base drug,and meanwhile reduce plug surface pressure.Under low-altitude conditions,the high flight speed is increased with the loss of toroidal aerospike nozzle performance.Influence of outflow attack angles on the plug nozzle performance is little,less than 1%.Compared with the conical nozzle,the thrust efficiencies of toroidal aerospike nozzle maintain higher value from ground to high altitude,especially obtaining more than 5%at sea level.