斜扩张管倾斜角度对催化转化器流动特性的影响

Influence of the Tilt Angle of Oblique Expansion Eube on Flow Characteristics in Automotive Catalyst Converter

采用计算流体动力学模型,利用三维建模软件(UG)对催化转化器进行三维建模,在Gambit中进行计算区域网格化和边界条件的定义.用计算流体动力学(CFD)软件FLUENT对4种不同入口扩张管倾斜角度的催化转化器的速度场、压力场进行三维稳态流动数值模拟.模拟结果表明:催化器入口扩张管倾斜角度对催化转化器的气流分布有很大影响,斜扩张管催化器由于倾斜角的不同,其压力损失也不同,压力损失并不是随着倾斜角的增大而增加,当倾斜角为30°时的压力损失最小;当斜扩张管的倾斜角小于40°时,催化器斜扩张管的倾斜角越大,流动均匀性指数越高,流速分布越均匀.

In this article,computational fluid dynamics（CFD） model is used,three-dimensional model of catalytic converters is created by UG,calculation of the regional grid and boundary conditions are defined in Gambit.Three dimensional numerical simulation about velocity field and pressure field of steady flows in the catalytic converters for four different inlet tube tilt angles is performed by using computational fluid dynamic software Fluent.The simulation results show that the entrance expansion tube tilt angle of the catalytic converter has a significant impact on the catalytic converter gas flow distribution.The pressure loss of the catalytic converter with oblique expansion pipe is changing with the angle of inclination.The pressure loss is not increased with the increasing angle of inclination.When the tilt angle is 30°,it has the minimum pressure loss.When the oblique inclination angle of the expansion tube is less than 40°,the catalytic converter oblique expansion tube tilt angle becomes larger,the flow uniformity index becomed higher,and the velocity distribution becomes more uniform.