柴油机喷嘴内流动现象及对喷雾的影响 车辆工程专业VIP免费

1柴油机喷嘴内流动现象及对喷雾的影响摘要燃油射流的破碎和雾化过程是柴油机和燃气轮机等工作过程的重要环节之一，对于柴油机和燃气轮机等燃烧过程和污染排放有着直接且重要的影响。近年来，针对燃油射流破碎及雾化现象，有关专家学者进行了细致的研究分析，发表了其研究理论。但是该现象自身复杂程度之大，使人们对于该现象的理解还具有局限性。随着现代科技的发展与进步，人们在这个问题上能够得到新的理解与认识。为了进一步研究喷油压力与速度可能对该燃油现象产生的作用。本文利用开源软件OpenFOAM平台，模拟喷孔并设定相关条件，用于对于该燃油现象的还原实验。分析实验数据，处理结果可以看出，喷油压力与喷油速度会对燃油射流的破碎和雾化过程产生很大影响。喷油压力和喷油速度的提高都有利于近孔区域燃油射流快速迸裂，使其液滴变得更加细小，促进柴油机中的燃油和空气混合更充分，从而提高柴油机的性能。关键词：喷孔近孔区域射流破碎雾化AbstractThecrushingandatomizationprocessoffueljetisoneoftheimportantlinksofdieselenginesandgasturbines,whichhasadirectandimportantimpactonthecombustionprocessandpollutionemissionsofdieselenginesandgasturbines.Althoughtheprocessoffragmentationandatomizationofthefueljethasbeenextensivelystudiedinrecentyears,manypracticalrelatedtheorieshavebeenproposed.Butduetothecomplexityofthecontent,thecurrentunderstandingofjetfragmentationandatomizationisfarfromenough.Withthedevelopmentandprogressofmoderntechnology,peoplecangetnewunderstandingandunderstandingonthisproblem.Inordertofurtherstudytheinfluenceofinjectionpressureandinjectionvelocityonthecrushingandatomizationofthefueljet,theopensourcesoftwareOpenFOAMplatformtomodeltheboundaryconditionsofthefueljetinthedieselnozzle.Afterthetreatmentandanalysisofthenumericalsimulationresults,itisfoundthattheoilinjectionpressureandtheoilinjectionspeedwillhaveagreatimpactonthecrushingandatomizationprocessofthefueljet.Theimprovementofoilinjectionpressureandoilinjectionspeedareconducivetotherapiddivisionofthefueljetinthenear-holearea,makingthefueldropletatomizationmoresubtle,andrealizingthebettermixingoffuelandairinthedieselengine,thusimprovingtheperformanceofthedieselengine.Keywords:OrificeNearholeareaJetbreakingAtomization2目录1绪论..............................................................................................................................................11.1研究背景及意义.................................................................................................................11.2国内外研究现状.................................................................................................................21.2.1喷嘴内燃油流动现象的研究概况..........................................................................21.2.2喷嘴内流动现象对雾化情况影响的研究概况......................................................21.3本文主要研究内容.............................................................................................................32柴油机喷嘴内空化现象及对喷雾影响的数学方法....................................................................42.1OpenFOAM简介.................................................................................................................42.2基本控制方程.....................................................................................................................62.3喷嘴的计算模型和边界条件.............................................................................................62.4数值方法.....................