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http://dx.doi.org/10.3795/KSME-B.2006.30.9.921

Wake-Induced Boundary Layer Transition on an Airfoil at Moderate Free-Stream Turbulence  

Park, Tae-Choon (서울대학교 마이크로열시스템연구센터)
Kang, Shin-Hyoung (서울대학교 기계항공공학부)
Jeon, Woo-Pyung (서울대학교 정밀기계설계공동연구소)
Publication Information
Transactions of the Korean Society of Mechanical Engineers B / v.30, no.9, 2006 , pp. 921-928 More about this Journal
Abstract
Wake-induced boundary-layer transition on a NACA0012 airfoil with zero angle of attack is experimentally investigated in periodically passing wakes under the moderate level of free-stream turbulence. The periodic wakes are generated by rotating circular cylinders clockwise or counterclockwise around the airfoil. The free-stream turbulence is produced by a grid upstream of the rotating cylinder, and its intensities $(Tu_{\infty})$ at the leading edge of the airfoil are 0.5 and 3.5%, respectively. The Reynolds number (Rec) based on chord length (C) of the airfoil is $2.0{\times}10^5$, and Strouhal number (Stc) of the passing wake is about 1.4. Time- and phase-averaged streamwise mean velocities and turbulence fluctuations are measured with a single hot-wire probe, and especially, the corresponding wall skin friction is evaluated using a computational Preston tube method. The patch under the high free-stream turbulence $(Tu_{\infty}=3.5%)$ grows more greatly in laminar-like regions compared with that under the low turbulence $(Tu_{\infty}=0.5%)$ in laminar regions. The former, however, does not greatly change the turbulence level in very near-wall region while the latter does it. At further downstream, the former interacts vigorously with high environmental turbulence inside the pre-existing transitional boundary layer and gradually loses its identification, whereas the latter keeps growing in the laminar boundary layer. The calmed region is more clearly observed under the lower free-stream turbulence level and with the receding wakes.
Keywords
Wake-Induced Transition; Free-Stream Turbulence; Turbulent Patch; Wall Skin-Friction Coefficient;
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  • Reference
1 Liu, X. and Rodi, W., 1991, 'Experiments on Transitional Boundary Layers with Wake- Induced Unsteadiness,' J. Fluid Mechanics, Vol. 231, pp. 229-256   DOI
2 Funazaki, K. and Koyabu, E., 1999, 'Effects of Periodic Wake Passing upon Flat-Plate Boundary Layers Experiencing Favorable and Adverse Pressure Gradients,' ASME J. Turbomachinery, Vol. 121, pp. 333-340   DOI
3 Wu, X., Jacobs, R. G., Hunt, J. C. R. and Durbin, P. A., 1999, 'Simulation of Boundary Layer Transition Induced by Periodically Passing Wakes,' J. Fluid Mechanics, Vol. 398, pp. 109-153   DOI
4 Park, T.-C., Jeon, W.-P. and Kang, S.-H., 2001a, 'Experimental Study of Boundary Layer Transition on an Airfoil Induced by Periodically Passing Wake: Part I - A Time-Averaged Characteristic,' Trans. of the KSME(B), Vol. 25, No. 6, pp. 776-785
5 Park, T.-C., Jeon, W.-P. and Kang, S.-H., 2001b, 'Experimental Study of Boundary Layer Transition on an Airfoil Induced by Periodically Passing Wake: Part II - A Phase-Averaged Characteristic,' Trans. of the KSME(B), Vol. 25, No. 6, pp. 786-798
6 Walker, G. J., Hughes, J. D. and Solomon, W. J., 1999, 'Periodic Transition on an Axial Compressor Stator: Incidence and Clocking Effects: Part I- Experimental Data,' ASME J. Turbomachinery, Vol. 121, pp. 398-407   DOI
7 Mayle, R. E., 1991, 'The Role of Laminar-Turbulent Transition in Gas Turbine Engines,' ASME J. Turbomachinery, Vol. 113, pp. 509-537   DOI
8 Halstead, D. E., Wisler, D. C., Okiishi, T. H., Walker, G. J., Hodson, H. P. and Shin, H., 1997a, 'Boundary Layer Development in Axial Compressors and Turbines: Part I-Composite Picture,' ASME J. Turbomachinery, Vol. 119, pp. 114-127   DOI
9 Schulte, V. and Hodson, H. P., 1998, 'Prediction of the Becalmed Region for LP Turbine Profile Design,' ASME J. Turbomachinery, Vol. 120, pp. 839-846   DOI
10 Hughes, J. D., Walker, G. J. and Gostelow, J. P., 1999, 'Identification of Instability Phenomena in Periodic Transitional Flows on Turbomachine Blades,' Proc. 14th Int'l Symposium on Air Breathing Engines, Florence
11 Nitsche, W., Thunker, R. and Haberland, C., 1983, 'A Computational Preston Tube Method,' Turbulent Shear Flow 4, Springer, pp. 261-276
12 Jeon, W.-P., Park, T.-C. and Kang, S.-H., 2002, 'Experimental Study of Boundary Layer Transition on an Airfoil Induced by Periodically Passing Wake,' Exps. Fluids, Vol. 32, No. 2, pp. 229-241   DOI
13 Pfeil, H., Herbst, R. and Schroder, T., 1983, 'Investigation of the Laminar-Turbulent Transition of Boundary Layers Disturbed by Wakes,' ASME J. Engineering for Power, Vol. 105, pp. 130-137   DOI