基区无吹氦环柱型高超音速低温喷管流场分析

FLOW FIELD ANALYSIS OF ANNULAR HYLTE NOZZLE ARRAY WITHOUT BASE PURGE

设计了小基区、基区不吹He的环柱型高能化学激光器环形HYLTE喷管阵列,并使用数值模拟的方法对环形HYLTE喷管阵列流场的气动性能和光学性能进行了分析．结果表明,该设计有利于形成v=1→v=0 之间振转跃迁谱线,不利于v=2→v=1之间振转跃迁谱线的形成,由于光腔区绝大多数的HF(2)分子碰撞去激活后成为HF(1)分子,从而使1P谱线的小信号增益倍增,无基区吹He的设计有利于提高高能化学激光器的效率．采用小基区的设计可以增大喷管阵列的功率流密度,无基区吹He的设计不但可以使复杂的环形高超音速低温喷管叶片的加工与装配得到简化,而且降低了激光器工作气体的消耗．因此该设计不但有利于实现高能激光器的紧凑化设计,还有利于节省高能激光器建造和运行的成本．

The annular Hypersonic Low Temperature （HYLTE） nozzle array is a gain generator of cylindrical high power chemical lasers. In this paper, a novel design of HYLTE nozzle without base purging is presented. Based on 3D Navier-Stokes equations and the realizable k-ε model, the multi-species reacting flow field of the annular HYLTE nozzle is calculated. The numerical simulation results show that eddies along the flow direction and highly twisted contact surfaces between fuel and oxidizer are major factors for rapid mixing and reacting rate of HYLTE. Multi spectra laser outputs are compared between the old HYLTE nozzle design and the new one, which shows that with the new HYLTE design, a total of 3 kW output power can be extracted from 1 g F atom reacting gas by BCAR resonator, howerver, only 1.6 kW can be extracted with the old design. In addition, the new design consumption of He used not only simplifies the fabrication of the complex HYLTE nozzle, but also reduces the in the high-energy chemical DF laser.