ARTICLE
Study on the behavior of streamwise vortices formed between leading edge tubercles in a compressor cascade
 
More details
Hide details
1
School of Aeronautics and Astronautics, Shanghai Jiao Tong University, Shanghai, China
Online publish date: 2019-07-15
Publish date: 2019-07-15
Submission date: 2018-08-20
Acceptance date: 2019-03-01
 
Journal of Theoretical and Applied Mechanics 2019;57(3):617–629
KEYWORDS
ABSTRACT
A study has been carried out to investigate the formation mechanism and development of streamwise vortices induced by leading edge tubercles in a high speed compressor cascade. The preliminary assessment of the cascade performance in terms of the total pressure loss coefficient shows that the loss reduction is achieved at high incidence angles. A smaller wavelength leads to higher additional losses at the design point, but gives rise to a greater loss reduction at high incidence angles. The modified cascade with a tubercle wavelength of 4% chord achieves the maximum loss reduction of 36.1% at i = 10◦, as well as the stall angle improvement of 27.6%. The formation mechanism of streamwise vortices is elaborated on the basis of the streamwise vorticity equation, in which the streamwise turning terms may be responsible for the generation of streamwise vortices. Slices of streamwise vorticity at various streamwise locations, combined with vorticity strength distributions, have been presented to study the development of streamwise vortices. The counter-rotating vortices are divided into the crest-induced streamwise vortices (CSVs) and trough-induced streamwise vortices (TSVs). A streamwise vortex pair formed from a part of the CSV sheets behind troughs, is gradually entrained by the TSV pair along the streamwise direction. In addition, the tubercles with a smaller wavelength result in higher streamwise vorticity strength with which the streamwise vortices interact with the flow separation more sufficiently and delay the separation to a greater extent.
 
REFERENCES (15)
1.
Dixon S.L., Hall C.A., 2013, Fluid Mechanics and Thermodynamics of Turbomachinery, Butterworth-Heinemann, Oxford.
 
2.
Favier J., Pinelli A., Piomelli U., 2012, Control of the separated flow around an airfoil using a wavy leading edge inspired by humpback whale flippers, Comptes Rendus Mecanique, 340, 107-114.
 
3.
Fish F.E., Battle J.M., 1995, Hydrodynamic design of the humpback whale flipper, Journal of Morphology, 225, 1, 51-60.
 
4.
Hansen K.L., Kelso R.M., Dally B.B., 2011, Performance variations of leading-edge tubercles for distinct airfoil profiles, Proceedings of AIAA, 49, 1, 185-194.
 
5.
Hansen K.L., Rostamzadeh N., Kelso R.M., Dally B.B., 2016, Evolution of the streamwise vortices generated between leading edge tubercles, Journal of Fluid Mechanics, 788, 730-766.
 
6.
Johari H., Henoch C., Custodio D., Levshin A., 2007, Effects of leading-edge protuberances on airfoil performance, AIAA Journal, 45, 11, 2634-2642.
 
7.
Keerthi M.C., Kushari A., De A., Kumar A., 2014, Experimental investigation of effects of leading-edge tubercles on compressor cascade performance, Proceedings of ASME, ASME GT2014-26242.
 
8.
Pedro H.T.C., Kobayashi M.H., 2008, Numerical study of stall delay on humpback whale flippers, Proceedings of AIAA, AIAA 2008-0584.
 
9.
Pérez-Torró R., Kim J.W., 2017, A large-eddy simulation on a deep-stalled aerofoil with a wavy leading edge, Journal of Fluid Mechanics, 813, 23-52.
 
10.
Rostamzadeh N., Hansen K.L., Kelso R.M., Dally B.B., 2014, The formation mechanism and impact of streamwise vortices on NACA 0021 airfoil's performance with undulating leading edge modification, Physics of Fluids, 26, 10, 107101.
 
11.
Skillen A., Revell A., Pinelli A., Piomelli U., Favier J., 2015, Flow over a wing with leading-edge undulations, AIAA Journal, 53, 2, 464-472.
 
12.
Steinert W., Eisenberg B., Starken H., 1991, Design and testing of a controlled diffusion airfoil cascade for industrial axial flow compressor application, Journal of Turbomachinery, 113, 4, 583-590.
 
13.
Weber P.W., Howle L.E., Murray M.M., Miklosovic D.S., 2011, Computational evaluation of the performance of lifting surfaces with leading-edge protuberances, Journal of Aircraft, 48, 2, 591-600.
 
14.
Zheng T., Qiang X., Teng J., Feng J., 2016, Application of humpback whale flippers in an annular compressor cascade, Proceedings of ASME, ASME GT2016-56589.
 
15.
Zheng T., Qiang X., Teng J., Feng J., 2018, Numerical loss analysis in a compressor cascade with leading edge tubercles, Journal of Theoretical and Applied Mechanics, 56, 4, 1083-1095.
 
eISSN:2543-6309
ISSN:1429-2955