摘要:
为研究高压燃气射流在整装液体中的扩展规律,探索提高射流稳定性的控制方法,设计了4级渐
扩型圆柱观察室。采用高速录像系统,观察了燃气射流在液体模拟工质中扩展与掺混的过程,获得了射流扩
展形态的序列照片,测量了Taylor空腔的扩展速度,对比了观察室内壁形状对射流扩展过程的影响。建立了
二维轴对称气液两相湍流模型,模拟射流扩展过程,计算得到的Taylor空腔扩展形态和扩展速度与实验吻合
较好。研究结果表明,渐扩型观察室台阶处出现涡流,诱导射流径向扩展,可抑制Kelvin-Helmholtz不稳定效
应,采用阶梯渐扩型边界有助于提高射流稳定性。
Abstract:
Inordertoinvestigatetheexpansioncharacteristicsofthehighpressurecombustiblegasjet
inabulk-loadedliquidandtoexplorethecontrolmethodsforimproveingthejetstability,acylindrical
four-stagestepped-wallchamberwasdesigned.Usingahigh-speedkinescopesystem,theexpansion
andmixingprocessofthegasjetintheliquidwasobserved.Aseriesofphotosdescribingjetexpansionform
wereobtained,theexpansionvelocityoftheTaylorcavitywasmeasuredandtheeffectsof
thechamberwallshapeonthejetexpansionwerecompared.A2-Daxisymmetricgas-liquidtwo-phase
turbulentflow modelwasdevelopedtosimulatethejetexpansionprocess.ThecalculatedjetexpansionshapeandexpansionvelocityoftheTaylorcavitywereconsistentwithexperimentalresults.
Obtainedresultsshowthatvortexemergesatthechambersteps,
whichinducesthejettoexpandradially
thenrestrainsKelvin-Helmholtzinstability.Thestepped-wallchamberboundarycanimprovethejet
stability.
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