柴油机排气微粒过滤器的一维流体动力学模型

One-Dimensional Fluid-Dynamic Model for Trapper in Diesel

提出了一个一维模型来模拟柴油机排气微粒过滤器内部的流体动力学行为。在一维流体动力学模型中 ,将排气微粒过滤器简化成内部设有压降元件的直管 ,简化的直管通过突变的截面与排气管连接 ,直管中间的压降元件是数学意义上的一个面 ,没有厚度 ,但具有实际过滤器的全部阻力。此模型能够反映过滤器内所发生的主要现象 ,如压力损失、温度变化、压力波的反射与传播。此模型被添加到 MK- 14程序中后 ,能够精确预测发动机与管路系统之间的相互作用与相互影响。模型通过试验得到了验证。

The aim of this paper is to present a new and simple approach to the one-dimensional modeling of the global fluid-dynamic behavior of the trapper placed in the diesel exhaust system.The one-dimensional model simplifies the trapper as a straight tube contained a device with adiabatic pressure loss.The straight tube is linked with exhaust pipes by sudden area change.The device with adiabatic pressure loss is of all resistance of the trapper.This submodel is able to represent the main phenomena taking place in the exhaust flow:mean pressure drop,mean temperature variations and instantaneous pressure wave reflection and transmission,and it can be linked to MK-14 code to predict the precise interaction and mutual influences between engine and trapper.The results of the model have been experimentally validated with tests on engine in real running conditions.