The space constraints of diesel vehicles make it difficult to design and
install stand-alone catalytic converters such as DOC, DPF, and SCR.
Therefore, the catalyzed substrates is installed inside the muffler to overcome
the space limitations. Such the muffler with a catalytic converter is referred as
the catalytic muffler,.which has complicated interior structures due to its
perforated plates, perforated tubes for noise reduction and catalytic converter
for emission reduction. Since flow uniformity can be a key parameter for
design of the catalytic muffler, this study focuses on the flow characteristics
inside the catalytic muffler to improve the performance of the muffler and
catalytic converter.
In the former cases, various experimental test results of muffler and
numerical simulations have been compared in terms of their features such as
attenuation properties and exhaust noise. Most existing studies focused on
noise reduction through acoustic reduction. However more technologically
advanced catalytic mufflers will be necessary to meet the stringent emissions
standards. The performance improvement of an after-treatment device system
for a catalytic muffler is very important. Computational fluid dynamics
results are presented for this tool.
As a preliminary study, a numerical investigation has been performed to
study the validation of perforate element induced discharge coefficient. After
conducting the validation of the present study comparing the present result
with the previously published(SCR) and the reaction experimental(DOC) data.
Considering the muffler internal flow and the reaction carried out research.
The purpose of this paper is to understand the tendency of catalytic muffler’s
reaction flow characteristics according to changes of interior structure
geometries and exhaust gas temperatures. The uniform distribution of fuel gas
flow (exhaust gas, soot) on the after-treatment device (catalyst, filter) is
critical for adequate long term performance of these after-treatment devices.