Open Access

ARTICLE

Numerical and Experimental Study of a Tornado Mixer

by Yibao Wang, Dongsheng Wang, Yudan Xue, Dailong Shi^*, Xiaoli Zhang, Yang Chai, Bang An

Center of Research and Department, WEICHAI Power Co., Ltd., Weifang, 261061, China

* Corresponding Author: Dailong Shi. Email:

(This article belongs to the Special Issue: Advances in Fluid Flow, Heat and Thermal Sciences)

Fluid Dynamics & Materials Processing 2021, 17(6), 1113-1127. https://doi.org/10.32604/fdmp.2021.017591

Received 22 May 2021; Accepted 02 July 2021; Issue published 08 September 2021

Abstract

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 NH₃ 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_X 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).

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Keywords

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