Men Y.,Changchun Institute of Technology |
Men Y.,Jilin University |
Lai Y.,SOYOTEC Ltd |
Dong S.,SOYOTEC Ltd |
And 2 more authors.
Transportation Research Part D: Transport and Environment | Year: 2017
The exhaust gas dispersion from the vehicles has a direct impact on human health, particularly on vehicle drivers, passengers, and people nearby. Because of the numerical implementation simplicity and well captured solution for fluid dynamics around multiple bodies, Lattice Boltzmann Method (LBM) has been adopted in lots of domains during the last two decades. This paper combines LBM together with Large Eddy Simulation (LES) turbulence model to study exhaust gas emission and dispersion characteristics. Carbon monoxide (CO) relative concentration and velocity distribution from a vehicular exhaust plume in the near-wake region is investigated for low and high idling driving conditions under different ambient wind speeds. Validation has been made to test the performance of gas simulation of the LBM-LES method in XFlow, after which 3D simulation of exhaust gas dispersion is considered, and the time-averaged CO relative concentration and velocity are analyzed. Results indicate that flow wake by ambient wind can affect the dispersion of exhaust gas. The exhaust gas moves downstream and spread to a wider range under higher ambient wind speed. While, the flow field becomes complicated due to the interflow effect when the wind speed and exhaust gas velocity are close, which enhances the dispersion characteristics of exhaust gas to a certain extent. © 2017
Shao L.,Guilin University of Electronic Technology |
Huang C.,Guilin University of Electronic Technology |
Liang Y.,Chengdu Aeronautic Vocational and Technical College |
Zhou X.,Guilin University of Electronic Technology |
Lai Y.,SOYOTEC Ltd
Hanjie Xuebao/Transactions of the China Welding Institution | Year: 2017
The 3D finite element analysis models of stacked AU bumps were developed, by using Isight software. The thermal-structure coupling analysis of the model was performed, the equivalent stress distribution of stacked AU bumps was obtained under the condition of thermal-structure coupling. The influence of the changes in stacked AU bumps structure on stress was studied. The influence significance of the below bump diameter, the below bump height, the above bump diameter, the above bump height on stress were obtained by variance analysis. The results of study show, the maximum stresses appear in the outer bump; With the increase of the bump height the highest stresses decrease gradually, with 99% confidence, the below bump diameter have highly significant impact on the stress, the below bump diameter, the above bump diameter, the below bump height, the above bump height affect the stress in a descending order. © 2017, Editorial Board of Transactions of the China Welding Institution, Magazine Agency Welding. All right reserved.