Experimental research and CFD analysis of flow parameters in a SCR system for the original part and WALKER’s replacement

Abstract

The article presents the results of experimental research and their comparison with CFD simulations for the original selective catalytic reduction system and WALKER replacement. The research was performed to develop the WALKER universal mixer. The SCR prototype without mixer and with the proposed mixer were tested and compared with the original VW part. The next step was reverse engineering, which consisted in scanning the tested parts with a laser and processing their point cloud in Leios2 program. Reverse engineering has allowed the reconstruction of 3D geometry of the tested parts in the Catia v5 program and then preparation their models for computational fluid dynamics. Numerical simulations were carried out in the Ansys Fluent program, thanks to which several quantities were determined e.g. uniformity index of gas flow through the monolith and coefficient of variation as a measure of mixing degree, which have a significant impact on the design of the mixer and the SCR system.

Numerical Simulations in SCR systems with Emphasis on Uniform Flow at the Catalyst Inlet

“…[ can be considered as a good result. [9] However, all the authors of publications related to this topic aim for the highest possible value of the uniformity index in their studies.…”

“…However, the effectiveness of the system is still increased when using the modules. [6] There are other articles also confirming the improvement of the system function, see [7] [8] [9].…”

Ammonia CI engine aftertreatment systems design and flow simulation

“…To utilize this approach source term Si has to be modelled. Following experimental results from [17,18] it can be modelled using Darcy-Forchheimer equation:…”