Measurements of flow quality in the Ames 2 x 2ft transonic wind tunnel

1981 ◽  
Author(s):  
F. OWEN
Author(s):  
Shenghao Wu ◽  
Jiming Chen ◽  
Qin Chen ◽  
Haitao Pei

Experimental studies were carried out in the 0.6 m×0.6 m continuous transonic wind tunnel of CARDC in order to investigate the flow characteristics of the slotted test section. Experimental results show that the root-mean-square deviation of axial Mach number in the model area is above 0.01 when the test section Mach number is above 1.0.Numerical simulation under the same conditions to investigate the flow characteristics of the slotted section, together with the experimental studies indicate tow phenomena may directly cause the Mach number fluctuation. Firstly, a straight section was installed to connect the nozzle and the test section in the wind tunnel. Weak shock waves due to the curvature discontinuity at the joint of the test section and the straight section contribute to Mach number fluctuation. Secondly, the open-area ratio of both the upper and lower wall of test section, each with 8 slots, is of 10%. The larger porosity leads to stronger expansion waves in the acceleration zone located at the inlet of the test section. The flow was over accelerated because of the stronger expansion wave and thus fluctuate the flow field severely. Two measures were taken to improve the flow quality of the slotted test section based on the above-mentioned analysis: ①Flexible plate instead of solid straight plate was installed to bridge nozzle and test section to eliminate the curvature discontinuity; ②Decreasing the open-area ratio of the upper and lower test section wall to 6% and the number of slots to 6. Numerical and experimental results show that the Mach number fluctuation in the model area was suppressed to a satisfactory degree.


Author(s):  
sergio oliveira ◽  
Ana Cristina Avelar ◽  
Henrique Leite ◽  
João Batista Pessoa Falcão Filho

2020 ◽  
Vol 32 (12) ◽  
pp. 125120
Author(s):  
María Jiménez-Portaz ◽  
Luca Chiapponi ◽  
María Clavero ◽  
Miguel A. Losada

2001 ◽  
Author(s):  
Norikazu Sudani ◽  
Mamoru Sato ◽  
Hiroshi Kanda ◽  
Toda Nobuhiro ◽  
Masashi Shigemi

2021 ◽  
Vol 1846 (1) ◽  
pp. 012004
Author(s):  
Qiang Xie ◽  
Yongtao Yin ◽  
Yin Li ◽  
Qingqing Cai ◽  
Yuanqiang Luo

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