@Article{fdmp.2020.07658,
AUTHOR = {Jiali Liu, Mengge Yu, Dawei Chen, Zhigang Yang},
TITLE = {A Study on the Reduction of the Aerodynamic Drag and Noise Generated By the Roof Air Conditioner of High-Speed Trains},
JOURNAL = {Fluid Dynamics \& Materials Processing},
VOLUME = {16},
YEAR = {2020},
NUMBER = {1},
PAGES = {21--30},
URL = {http://www.techscience.com/fdmp/v16n1/38330},
ISSN = {1555-2578},
ABSTRACT = {In order to investigate how the aerodynamic drag and noise produced by the 
roof air conditioner of a high-speed train can be reduced, the related unsteady flow in the 
near-field was computed using the method of large eddy simulation. In this way, the 
aerodynamic source for noise generation has initially been determined. Then, the far-field 
aerodynamic noise has been computed in the framework of the Lighthill’s acoustics 
analogy theory. The propulsion height and flow-guide angle of the roof air conditioner 
were set as the design variables. According to the computational results, a lower 
propulsion height or flow-guide angle is beneficial in terms of aerodynamic drag and 
noise mitigation. However, compared to the design scheme with propulsion height of 
0mm, the aerodynamic drag coefficient of the configuration with propulsion height of 
190mm and flow-guide angle of 30° is slightly larger, while the aerodynamic noise is 
obviously reduced. Thus, from the viewpoint of the aerodynamic drag and noise, the 
design scheme with propulsion height of 190 mm and flow-guide angle of 30° is the 
optimal configuration in the range of conditions examined in the present work.},
DOI = {10.32604/fdmp.2020.07658}
}