实验流体力学2011，Vol.25Issue(3)：20-23,4.
暂冲式风洞大开角扩散段性能的实验研究
Experimental research of wide-angle diffuser performance for the intermittent wind tunnel
黄知龙 1张国彪 1刘晓波 1耿子海1
作者信息
- 1. 中国空气动力研究与发展中心空气动力学国家重点实验室,四川绵阳621000
- 折叠
摘要
Abstract
The starting time for the intermittent wind tunnel can be effectively reduced by parametric optimization design of the wide-angle diffuser with multilayer perforated plates, which makes flow velocity into the settling chamber uniform and reduces noise and flow fluctuation behind the valve. The paper studies key design techniques for the wide-angle diffuser of a largescale intermittent wind tunnel. Various experiments combining with different diffusing angles and different centerbody cones are conducted. Comparative analysis from pressure loss, velocity distribution at exit of diffuser and noise reduction characteristics are performed. The experimental results show that minimum pressure loss can be obtained when 45°diffuser combining with 65°truncated cone is utilized. But the pressure loss will apparently increases due to no steady separation vortex evolution if the centerbody tail cone is added. For other combinations of diffusers and cones with different angles, similar pressure losses can be found. From the results, we can also see the axisymmetric hump trend of dynamic pressure distributions at the exit for various diffuers and smoother velocity distributions when the perforated plate has a higher perforation ratio. Additionally, we find that the flow noise suppression level can approximately reach 12～ 14dB for some test Mach numbers if the wide-angle diffuser is used, especially for the frequency above 2kHz. Moreover, the flow fluctuation amplitude is obviously reduced after the air flows through the wide-angle angle with multilayer perforated plates.关键词
大开角扩散段/孔板/降噪/暂冲式风洞/实验Key words
wide-angle diffuser/ perforated plate/ noise reduction/ intermittent wind tunnel/experiment分类
航空航天引用本文复制引用
黄知龙,张国彪,刘晓波,耿子海..暂冲式风洞大开角扩散段性能的实验研究[J].实验流体力学,2011,25(3):20-23,4.
