The effect of ejector augmentation on test-section flow quality in the Calspan 8-ft transonic wind tunnel

1982 ◽  
Author(s):  
W. ROSE ◽  
R. HANLY ◽  
F. STEINLE, JR. ◽  
D. CHUDYK
Keyword(s):  
Wind Tunnel ◽  
Test Section ◽  
Flow Quality ◽  
Transonic Wind Tunnel

scholarly journals Measurementimprovement of flow quality of slotted test section in transonic wind tunnel

2021 ◽  
Vol 39 (3) ◽  
pp. 660-667
Author(s):  
Shenghao Wu ◽  
Jiming Chen ◽  
Qin Chen ◽  
Haitao Pei
Keyword(s):  
Mach Number ◽  
Wind Tunnel ◽  
Test Section ◽  
Experimental Studies ◽  
Flow Characteristics ◽  
Area Ratio ◽  
Straight Section ◽  
Flow Quality ◽  
Transonic Wind Tunnel

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.

Suppression of background noise in a transonic wind-tunnel test section

AIAA Journal ◽  
1975 ◽  
Vol 13 (11) ◽  
pp. 1467-1471 ◽  
Author(s):  
L. A. Schutzenhofer ◽  
P. W. Howard
Keyword(s):  
Wind Tunnel ◽  
Test Section ◽  
Background Noise ◽  
Wind Tunnel Test ◽  
Transonic Wind Tunnel

Control of separation in the concave portion of contraction to improve the flow quality

2009 ◽  
Vol 113 (1141) ◽  
pp. 177-182 ◽  
Author(s):  
K. Ghorbanian ◽  
M. R. Soltani ◽  
M. D. Manshadi ◽  
M. Mirzaei
Keyword(s):  
Wind Tunnel ◽  
Pressure Distribution ◽  
Turbulence Intensity ◽  
Test Section ◽  
Adverse Pressure Gradient ◽  
Wind Tunnel Experiments ◽  
Free Stream Turbulence ◽  
Static Pressure Distribution ◽  
Subsonic Wind Tunnel ◽  
Flow Quality

AbstractSubsonic wind tunnel experiments were conducted to study the effect of forced transition on the pressure distribution in the concave portion of contraction. Further more, the effect of early transition on the turbulence level in the test section of the wind tunnel is studied. Measurements were performed by installing several trip strips at two different positions in the concave portion of the contraction. The results show that installation of the trip strips, have significant effects on both turbulence intensity and on the pressure distribution. The reduction in the free stream turbulence as well as the wall static pressure distribution varied significantly with the location of the trip strip. The results confirm the significant impact of the tripped boundary layer on the control of adverse pressure gradient. The trip strip atX/L= 0.115 improves pressure distribution in contraction and reduces turbulence intensity in the test section, considerably.

A Small Wind Tunnel Significantly Improved by a Multi-Purpose, Two-Flexible-Wall Test Section

1994 ◽  
Vol 116 (3) ◽  
pp. 419-423 ◽  
Author(s):  
P. Kankainen ◽  
E. Brundrett ◽  
J. A. Kaiser
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Test Section ◽  
Side Wall ◽  
Reynolds Numbers ◽  
Free Data ◽  
Wall Panels ◽  
Testing Data ◽  
Flexible Wall ◽  
Flow Quality

A small open-return wind tunnel has been renovated to include a longer test section with a flexible roof and floor and improved entrance flow quality. The flexible-wall test section allows models with up to 30 percent nominal blockage to be tested, resulting in a significant increase in the maximum attainable Reynolds numbers. Interchangeable rigid side-wall panels allow flexibility of application which is essential for a university wind tunnel facility. Configurations have been developed for automotive, aerodynamic and atmospheric-boundary-layer testing. Data acquisition and wall positioning are at an economical semi-automated level of operation. The flexible-wall concept has been well-documented previously, and provides interference-free data without flow pattern assumptions after a few iterations of the roof and floor shape. Representative data are presented for a circular cylinder and an airfoil.

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