TY  - EJOU
AU  - Wang, Yibao 
AU  - Wang, Dongsheng 
AU  - Xue, Yudan 
AU  - Shi, Dailong 
AU  - Zhang, Xiaoli 
AU  - Chai, Yang 
AU  - An, Bang 

TI  - Numerical and Experimental Study of a Tornado Mixer
T2  - Fluid Dynamics \& Materials Processing

PY  - 2021
VL  - 17
IS  - 6
SN  - 1555-2578

AB  - A new design of a selective catalytic reduction (SCR) mixer called tornado was developed for a heavy-duty diesel engine to solve the urea deposition problem. A combination of CFD simulation and experimental studies was used to comprehensively evaluate the performance of the tornado mixer. According to the numerical simulations, this mixer can improve the front surface flow uniformity of the SCR carrier by 6.67% and the NH<sub>3</sub> distribution uniformity by 3.19% compared to a traditional mixer. Similarly, steady state SCR conversion efficiency test results have shown that the tornado mixer can increase the average SCR conversion efficiency by 1.73% compared to a traditional mixer. Therefore, the tornado mixer outperforms traditional mixers in terms of mixing uniformity, resistance to deposition and impact on NO<sub>X</sub> emissions. In addition, a dimensionless parameter, the “limiting deviation rate”, is proposed in the present study to improve the mixing uniformity assessment method for SCR mixers (with the explicit intent to evaluate the mixing uniformity more accurately).
KW  - Diesel engine aftertreatment; SCR mixer; urea deposition; CFD simulation; experimental verification

DO  - 10.32604/fdmp.2021.017591