3D CFD based parameterization and shape optimization of diesel SCR after treatment system

Abstract

After- treatment treats post-combustion exhaust gases prior to tailpipe emission. It allows for greater power from the engine without worrying about emissions increasing. After-treatment Differs from emission reduction techniques in the combustion process. Devices developed for after treatment of exhaust emissions includes thermal converters or reactors, filters for particulate matters and catalytic converters. The performance of automotive catalytic converters is affected by the flow distribution within the Domain. The non-uniformities of the flow field at the inlet of the catalytic converter are considered to have a negative impact on the converter performance. Poor flow distribution is also indicative of higher system pressure losses which implies reduced engine performance and a deterioration in fuel economy. Present study included study and use of traditional DOE methods and tools (MINITAB, excel) to understand relationship between input and output parameters referred to as a transfer function using a downpipe geometry typically used to connect the turbo outlet to the main after treatment system. Tools such as ANSYS Design Exploration and mode-Frontier containing advance Design of Experiment algorithms were studied and applied to Inlet section of a typical after treatment system containing a catalyst. Sculptor, the commercial shape optimization software is used to automatically adjust the shape of the cone diffuser. Finally the most recommended workflow for carrying out such optimization studies for after-treatment system is presented.