摘要:
针对燃爆压裂过程中压挡液柱受冲击运动机理的复杂性,假设火药燃气与压挡液柱存在完全气液
接触界面,采用拉格朗日的微元分析方法,建立了由连续性方程、动量守恒方程、能量守恒方程组成的压挡液
柱运动规律动力学模型,并给出了该模型与火药燃爆模型的耦合数值解法。经程序编制和实例计算表明,在
综合考虑火药燃气对液柱的宏观推动作用、冲击压缩作用、液柱自身的动能分布及管壁对其摩擦阻力的影响
后,火药燃烧过程中气液界面上升高度有限(实例计算不足0.1m),可起到很好的持压作用;但全过程中最高
液柱位移较大(18.9m),水力振荡增效作用明显。研究成果对提高燃爆压裂的数值模拟精度具有一定促进
作用。
Abstract:
Accordingtothekinematicalmechanismcomplexityoftheimpactedpressurizedliquidcolumninthehighenergygasfracturingprocess,
weassumesthatthecompletelycontactedgasliquidinterfaceexits.
ThenbyusingaLagrangeanalyticalmethodforstudyingarandomliquidacross-section,
adynamicmodelofthepressurizedliquidcolumnmovementlawissetup,whichcomprisescontinuityequation,
momentumconservativeequationandenergyconservativeequation.Basedonthe
pressureandvolumeconservationduringtheprocessofpowderconflagrationandpressurizedliquid
columnmovement,acouplingnumericalmethodfordescribingthegas-liquidinterfacemovementlaw
isestablished.Examplecalculationsshowthatwhenconsideringthemacroscopicalpropelandimpact
compressiononthepressurizedliquidcolumncausedbydeflagration,dynamicenergydistributionof
theliquiddistributionandpipecolumnfrictionresistance,theinterfaceascendingheightislimited
(lessthan0.1mintheexampleconditions).Thisillustratesthatpressurizedliquidcolumnhasagood
functionofbackingpressure.Butinfact,inthefracturingprocess,theinterfacecanreachahigher
position(18.9m),whichshowsthatinthelaterprocess,hydraulicoscillationproducesanobvious
synergisticeffect.
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