考虑针阀运动的LPG高压旋流喷油器内外流动过程的数值解析  

Numerical Analysis of Internal Flow and Spray for a LPG High Pressure Swirl Injector with Needle Movement

作　　者：张现成[1] 许伯彦[1] 

机构地区：[1]山东建筑大学机电工程学院,山东济南250101

出　　处：《内燃机学报》2013年第3期228-234,共7页Transactions of Csice

基　　金：国家自然科学基金资助项目(51076085);山东省科技计划资助项目(2007GG10007004)

摘　　要：采用AVL FIRE软件,数值解析了考虑针阀运动过程时,液化石油气(LPG)在旋流喷油器内部气穴流动过程以及LPG喷出后的喷雾发展过程.解析过程中使用了基于LPG燃料热物性修正的喷雾模型,结果表明:在针阀开启后的整个LPG喷射持续期内,喷油器内的气穴流动现象一直存在;而使用汽油为燃料时,仅在针阀开启前期时旋流喷油器喷孔壁拐角处有气穴产生,但随着针阀升程进一步增大,拐角处的气穴区变小进而消失.将喷油器内部流动的解析结果作为喷油器出口条件,并使用修正后的喷雾模型,数值解析了LPG和汽油的喷雾发展过程.经与试验结果对比显示,解析结果和试验结果之间具有良好的一致性.与汽油相比,燃料喷射过程中产生的减压沸腾现象使得LPG的喷雾锥角增大,而喷雾贯穿距离则减小.The cavitating flow phenomenon in a LPG high pressure swirl injector with needle movement was analyzed using the multiphase module of AVL’s FIRE CFD code.The validated spray model was used in the simulation.Simulation results show that cavitation zone exists during the entire injector needle opening process for the LPG,but for the gasoline,the cavitation zone is formed on the wall of the nozzle entrance during the early stage of needle opening.As needle opens further,cavitation zone becomes small and eventually disappears.Free spray process of LPG and gasoline was simulated using the initial conditions of the calculated internal flow of the swirl injector.Simulation results have a good agreement with the experimental data.Spray cone angle increases but penetration distance of LPG decreases compared with those of gasoline,which is caused by the flash boiling occurred in the spray process.

关 键 词：液化石油气 旋流喷油器 气穴 减压沸腾 数值解析 

分 类 号：TK464[动力工程及工程热物理—动力机械及工程]