Control of Pressure Gradient in the Contraction of a Wind Tunnel

Authors: Dehghan Manshadi M., Mirzaei M., Soltani M. R., Ghorbanian K.

Abstract:

Subsonic wind tunnel experiments were conducted to study the effect of tripped boundary layer on the pressure distribution in the contraction region of the tunnel. Measurements were performed by installing trip strip 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 and pressure distribution. The reduction in the free stream turbulence and reduction of the wall static pressure distribution deferred signified with the location of the trip strip.

Keywords: Contraction, pressure distribution, trip strip, turbulence intensity.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1083099

References:

[1] F. Fang, J. C. Chen, "Experimental and Analytical Evaluation of Flow in a Square-to-square Wind tunnel Contraction," Journal of Wind Engineering and Industrial Aerodynamics 89 (2001) 247-262.
[2] G. E. Chmielewski, "Boundary Layer Considerations in the Design of Aerodynamic Contractions," McDonnell Douglas Research Laboratories, St. Louis, Mo, VOL. 11,No.8, August 1974.
[3] J. Bottcher, E. Wedemeyer, "The Flow Downstream of Screens and its Influence on the Flow in the Stagnation Region of Cylindrical bodies," Journal of Fluid Mechanics, 204, 501-522, 1989.
[4] T. Sonada, Y. Aihara, "Effects of Pressure Gradient on the Secondary Instability of Gortler Vortices," A.I.A.A. Paper 81-0197, 1981.
[5] P. Bansod, P. Bradshaw, "The flow in S-shaped ducts," Aeronautical Quarterly, 23(2), 131-140, 1972.
[6] S. Takagi, A. Nishizawa, N. Tokugawa, "Observation of Gortler Vortices in Wind-tunel Contraction Boundary Layer," Proc. 3rd Int. Symposium on Turbulence, Heat and Mass Transfer, (2000) 275-282.
[7] S. Takagi, N. Tokugawa, "Laminar-Turbulent Transition Along The Contraction Nozzle in Subsonic Flow," 37th AIAA Aerospace Sciences Meeting and Exhibit, 99-0279, Japan, January 11-14, 1999.
[8] A. Nishizawa, S. Takagi, N. Tokugawa, "rebirth of Turbulence in Laminarized Boundary Layers Along the wind-tunnel Contraction," National Aerospace Laboratory, Chofu, Tokyo 182-8522, Japan, Tadashi SOBAGAKI, Aoyama Gakuin University, Setagaya, Tokyo 157-8572, Japan.
[9] M. R. Soltani, M. Dehghan Manshadi, M. J. Mirabdollahi, "Flow Quality Study in a subsonic Wind Tunnel ," ISME 2004 Conference, Tehran, Iran, 2004.
[10] M. R. Soltani, M. Dehghan Manshadi, M. J. Mirabdollahi, "An Experimental Study of the Flow Characteristics in a Subsonic Wind Tunnel," International Mechanical Engineering Conference, December 5-8, Kuwait, 2004.
[11] H. Ito, R. Kobayashi, Y. Kohama, "The Low-Turbulence Wind Tunnel at Tohoku University," Aeronautical Journal pf the Royal Aeronautical Society, April 1992.