爆震发动机扩张型引射喷管的非定常流动过程研究

ComputationalStudyonUnsteadyFlowsinaDivergingEjectorforPulseDetonationEngine

关键词:  脉冲爆震发动机  扩张型引射器  积分冲量  数值模拟中图分类号:V235.22文献标识码:A文章编号:1001-4055(2015)12-1781-07DOI:10.13675/j.cnki.tjjs.2015.12.004

Key words:  Pulsedetonationengine  Divergingejector  Integralimpulse  Computationalanalysis

摘要:

为揭示PDE引射喷管的瞬态流动机理，采用带化学反应的非定常仿真方法，对使用二维扩张型引射器PDE的非定常排气过程进行分析，获得了流场结构的瞬态演化过程，并将其单循环的积分冲量与无引射喷管状态进行了对比。结果表明，仿真中形成了稳定的爆震波，其主要特性参数与理论值相差较小，并且仿真获得爆震排气过程的流动结构与试验结果吻合良好。带引射器PDE的单循环主要流动过程可以分为:爆震波产生和排出阶段、引射器主动进气阶段、爆震管第一次倒流阶段、爆震管主动排气阶段、爆震管第二次倒流阶段。相比无引射器状态，使用扩张型引射器可以使PDE单循环积分冲量增加21.76%，并且其对爆震管头壁压强、单次循环周期无明显影响。

Abstract:

UtilizingtheunsteadyCFDmethodwithchemistryreaction，theunsteadyexhaustingprocessinapulsedetonationengine(PDE)equippedwithatwo-dimensionaldivergingejectorisanalyzedtorevealtheunderlyingunsteadyflowmechanism.Thetransientflowstructuresintheejectorarecarefullyexaminedandtheintegralimpulseofasinglecycleofthesystemiscomparedwiththenon-ejectorcase.Accordingtothecomputa.tionalresults，asteadydetonationwaveisformedinthePDEcombustor，ofwhichthecriticalparametersareclosetothetheoreticalones.Also，thecalculatedflowstructuresoftheexhaustingprocessagreewellwiththeex.perimentalresults.TheflowprocessofatypicalcycleofthePDEwithejectorcanbedividedintofivemainphas.es，namely，detonationwavegenerationandexhaustingphase，ingestingphaseforejector，thefirstreversedflowphaseforPDEcombustor，activelyexhaustingphaseforPDEcombustor，thesecondreversedflowphaseforPDEcombustor.Ascomparedwiththenon-ejectorcase，theintegralimpulseofasinglecycleofthePDEwithejectorisenhancedby21.76%andthepressurehistoryoftheheadwallandthecyclelengtharebasicallyun.changed.