Lattice Boltzmann simulation of forced convection in partial porous channel with application in exhaust gas recirculating (EGR) coolers

Diesel engines are one of the main sources of NOx emission, which occurs due to the high flame temperature in such engines. Using an exhaust gas recirculation (EGR) system is one of the methods introduced to reduce the flame temperature and consequently the NOx emission in diesel engines. The EGR gas is usually passed through a cooler for its temperature to be reduced before reentering the cylinder to increase the efficiency of an EGR system. Because of the high-temperature gradients in the cooler, the particles fouling on the cooler's surface are very likely to occur which disrupts the system's performance. Using the EGR system helps to reduce NOx, but instead, it causes the increment of a particular matter and soot particle according to the incomplete combustion. These produced particles deposit on the cooler walls and create a porous layer that disrupts the system's hydrodynamic and heat transfer performance. In this paper, a partial porous channel is considered as a simple single-passage EGR cooler. The lattice Boltzmann method (LBM) is used to numerically investigate the effect of different Darcy-number (۰.۱, ۰.۰۱, ۰.۰۰۱) and various dimensionless blockage ratios by the porous layer ( = ۰.۲, ۰.۴, ۰.۶) on hydrodynamic and heat transfer performance.

کلیدواژه ها:

NOx emission ، diesel engines ، exhaust gas recirculation cooler ، partial porous channel ، lattice Boltzmann method