摘要
以内燃机排气歧管三分支管接头内可压缩流动损失研究为背景,对45°三分支管接头的汇合流动进行定常试验研究,获取了在不同流动参数工况下气体流经三分支管接头时的流动数据。两个支管与主管截面积的面积比分别为1和1.56,分支夹角的交界点处以及支管的转角处都为锐角边缘。利用测试所得的数据对比分析不同工况压力损失的变化规律。试验结果表明:相比于接头处的压力损失,接头管内壁摩擦对压力损失影响较小;汇合流时,两个入流管端的静压几乎相等,出流管端的压力总是小于入流管端的压力,且随着马赫数的增大,压差也增大;流动参数的不同将影响和改变三分支气流的压力损失,其中随着支管和总管流量比的增大,总压损失系数K13、K23先增大后减小,但峰值点的位置随工况参数的不同而变化;流出端马赫数对压力损失也存在影响,马赫数为0.13和0.31时,总压损失系数变化不大,当马赫数增大到0.59时,总压损失系数大幅度增加。试验结果为分析动力管网系统中多管接头压力损失及建立排气歧管可压缩流一维计算模型奠定了基础。
The inner flow in a 45°sharp-edged T-junction is measured on the pressure loss of the exhaust system.Pressure loss of compressible combining flow at two junctions is obtained at different flow conditions.Junctions are manufactured with area ratios ofφ=1and 1.56 respectively.In addition,the axes in all branches are coplanar and the corners at the point of intersections between lateral branch and main branch are sharp edged.Comparative analysis the data of pressure loss,the results indicate that pressure loss is mainly dependent of＂junction loss＂in the junction flow.The static pressure in the common branch is always lower than that of the inflow across the entire range of the mass flow rate ratio.Additionally,with increasing M3,the compressibility of the fluid significantly increases.The static pressure in the inflow branches 1and 2are equal in the present study.Flow parameters have been related to the Mach number in common branch and the mass flow rate ratio between branch and duct.As the mass flow rate ratio of branch and duct increased,the total pressure loss coefficient K13 and K23increased first and then decreased,while the peaks are different.The variation in the total pressure loss coefficient with Mach number in common branch is fairly small in the range of 0.13 to 0.31.However,alongwith the Mach number M3 increases to 0.59,the coefficient increases more rapidly.The results provide reference for the research of pressure loss and the boundary condition in one-dimensional junction compressible models.
出处
《空气动力学学报》
CSCD
北大核心
2015年第6期780-786,共7页
Acta Aerodynamica Sinica
关键词
分支接头
流动参数
流量比
马赫数
压力损失系数
junction
flow parameters
mass flow rate ratio
Mach number
pressure loss coefficient
