V型多缸柴油机润滑系统流动特性三维仿真研究

发布时间：2018-01-07 13:18

本文关键词：V型多缸柴油机润滑系统流动特性三维仿真研究　出处：《北京理工大学》2015年硕士论文　论文类型：学位论文

【摘要】：润滑系统是柴油机的重要系统之一,是柴油机高效可靠工作的重要保证;活塞冷却喷嘴将机油喷入冷却油腔,带走活塞顶部的大部分热量,其工作性能的好坏对柴油机的安全可靠运行有直接影响。本文以一台V型多缸柴油机的润滑系统为研究对象,对润滑油道和活塞喷油冷却的机油流动特性进行了三维仿真研究。本文使用Solidworks建立了柴油机润滑系统油道和活塞喷油冷却机油流动计算域的几何模型,润滑系统油道模型包括附件托架体内的辅助油道、机油散热器、机油滤清器、曲轴箱体内主油道以及各润滑部位的简化油道等,活塞喷油冷却模型包括活塞冷却喷嘴油道、活塞下部腔体、内冷油腔等。本文使用Fluent软件对润滑油路标定工况下调压阀打开时的流场进行仿真研究。结果表明:机油在整个附件托架内的压力损失为0.352 MPa,在主油道内的压降为0.145 MPa;主油道中,供油凸轮轴轴承润滑油道压力最高,左排主油道压力最低;右排主油道流量最高,供油凸轮轴轴承润滑油道流量最低。在各出口中,配气凸轮轴轴承润滑油道的泄油量最大,增压器轴承的泄油量最小,配气凸轮轴轴承润滑油道流量不均匀度最高。本文研究了标定工况下调压阀关闭时,润滑系统油道机油的流动特性,结果表明:流场的机油压力比调压阀打开时整体提高了0.18MPa左右;主油道内,左右两排主油道流量降低了,供油凸轮轴轴承润滑油道的流量则提高了;主油道末端出现了右排主油道机油向左排主油道供油的现象;调压阀之外的所有出口的机油流量都增加了,单体泵润滑油路的机油流量增加比例最高;只有增压器轴承出口流量不均匀度减小了,其他出口流量不均匀度都增加了。本文对不同入口流量下、活塞在不同位置,活塞喷油冷却的流场进行仿真计算。结果表明:机油离开喷嘴后,液柱的直径变大,液柱呈现中心速度高,周围速度低的状态;活塞在下止点到距下止点16mm位置处,机油撞壁点靠近内冷油腔入口,在16mm到32mm位置处,撞壁点位于内冷油腔入口内,在32mm到145mm位置处,撞壁点远离内冷油腔入口;没有进入内冷油腔的机油在撞壁后仍然沿壁面流动,机油在撞壁后分散形成了数条油束;活塞在距下止点16mm、32mm位置处机油全部进入内冷油腔,活塞距在下止点96mm到上止点位置没有机油进入内冷油腔;活塞在距下止点16mm位置内冷油腔腔内机油体积分数最高,活塞在下止点内冷油腔壁面的机油体积分数最高。
[Abstract]:The lubrication system is an important system of the diesel engine, the diesel engine is an important guarantee for efficient and reliable work; piston cooling nozzle oil sprayed into the cooling oil chamber, most of the heat away at the top of the piston, has a direct impact on the safe and reliable operation of the diesel engine. Its performance is based on the lubrication system of a V type multi cylinder the diesel engine as the research object, the oil flow characteristics of lubricating oil and piston injection cooling of 3D simulation. This paper uses Solidworks to establish the geometric model of the diesel engine lubrication system oil and piston oil cooling oil flow of the computational domain, the auxiliary oil lubrication system, oil channel model including bracket body oil radiator oil filter, crankshaft box body, the main oil and the lubricating parts to simplify the oil road, model of oil cooling piston comprises a piston cooling nozzle oil duct, the lower part of the piston cavity, The inner cooling oil chamber. This paper use Fluent software for lubrication rated pressure valve open when the down flow is simulated. The results show that the pressure loss of the oil in the whole bracket within 0.352 MPa, the pressure drop in the main oil channel is 0.145 MPa; the main oil, lubricating oil and camshaft bearing the highest pressure, left the main oil pressure is lowest; the right row of the main oil flow rate is highest, the cam shaft bearing lubricating oil passage. The minimum flow rate in each outlet cam shaft bearing lubricating oil channel to drain the largest amount of oil discharge turbocharger bearing the minimum cam shaft bearing lubrication the oil flow uniformity is studied in this paper. The highest rated voltage regulating valve is closed, flow characteristics, lubrication system oil oil the results showed that the flow field of the oil pressure than the pressure regulating valve is open to improve the overall 0.18MPa; the main oil channel, about two rows of main oil Road traffic is reduced, the cam shaft bearing lubrication oil duct flow is improved; the main oil channel appears at the end of the right row of the phenomenon of oil oil left main oil supply row; oil flow regulating valve outside of all exports have increased, the oil flow rate of single pump lubricating oil increases the highest proportion only; bearing of turbocharger outlet flow uniformity decreases, other outlet flow uniformity are increased. The different entrance flow, the piston in the different position, flow piston injection cooling was simulated. The results show that the oil left after the nozzle, the larger diameter of liquid column, liquid column show center high speed, low speed around the state; the piston in the BDC to stop 16mm distance under oil, hit the wall near the entrance to the inner cooling oil chamber, at the position of 32mm in the 16mm, hit the wall at the inner cooling oil chamber entrance, to the 145mm position in the 32mm, hit The wall away from the inner cooling oil chamber entrance; did not enter the inner cooling oil chamber oil in hit the wall after the still flow along the wall, hit the wall after the oil dispersion formed a number of oil beam; piston check points in the 16mm distance, 32mm position of oil into the inner cooling oil chamber, the piston from the next stop 96mm to TDC no oil into the inner cooling oil chamber; the piston from the bottom dead point position of 16mm inner cooling oil cavity oil volume fraction is highest, the piston in the bottom wall of the inner cooling oil chamber oil volume fraction is highest.

【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK423

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