THE IMPACT OF A VORTEX GENERATOR ON A MIXTURE OF A JET WITH A MAINSTREAM FLOW OVER A FLAT PLATE

Nabeel Al-zurfi

doi:10.30572/2018/KJE/160330

Authors

Nabeel Al-zurfi Department of Mechanical Engineering, Faculty of Engineering, University of Kufa, Al-Najaf, Iraq

DOI:

https://doi.org/10.30572/2018/KJE/160330

Keywords:

Vortex generator, Film cooling, Turbulence flow, Jet interaction

Abstract

This work investigates the effects of adding vortex generators (VGs) in front of twin injection holes drilled on a flat plate geometry. To analyse the improvement of heat transfer, VGs are positioned at three different locations: 0D, D, and 3D upstream of the injection holes. The configurations used are prism-shaped VG of height = D, 1.5D, 2D, and 3D, with an inclination angle of 0° to 40°, and a blowing ratio of M=1.0. Using the commercial CFD code StarCCM+, the focus is on temperature distribution to examine the improvement of the injected jet coverage on the wall. The sst k-w turbulence model of the Reynolds-averaged Navier-Stokes method (RANS) is used to model the turbulent flow over a flat plate. The accuracy of the RANS approach to predict the jet in crossflow interaction (JICF) is evaluated in this study. The effective operation of this cooling enhancement is demonstrated by the region covered by the injected air along the flow direction. The results showed that the VG location is the crucial factor that controls the jet coverage. Compared to the base hole, the cooling performance produced by the VGs design exhibits obvious enhancement at all VGs locations. The jet footprint of the VG cases is larger than that of the base hole. Besides, it was also shown that the VG technique applied in the current research decreases the mixing process between the mainstream air and the secondary jet and enhances the coverage level. It was also found that the VGs generate strong reverse vortices moving against the main vortices, which destroys their undesirable effects and reduces the jet lift-off effect which then keeps the jet attached to the wall. In conclusion, the simulation results indicate a greater coverage area can be achieved when the VG is mounted at an upstream location too far from the injection hole

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References

Ajersch, P. et al., (1997). Multiple jets in a crossflow: Detailed measurements and numerical simulations. Journal of Turbomachinery, 119(2), pp.330–342. https://doi.org/10.1115/1.2841116.

Alhusseny, A. et al., (2023). A porous media approach for numerical optimisation of thermal wheel. Kufa Journal of Engineering, 14(4), pp.56–68. https://doi.org/10.30572/2018/KJE/140405.

Alhusseny, A. et al., (2023). Graphite foam structures as an effective means to cool high-performance electronics. Kufa Journal of Engineering, 15(2), pp.39–60. https://doi.org/10.30572/2018/KJE/150204.

Andreopoulos, J. and Rodi, W., (1984). Experimental investigation of jets in a crossflow. Journal of Fluid Mechanics, 138, pp.93–127. https://doi.org/10.1017/S0022112084000057.

Deng, H. et al., (2022). Overall cooling performance evaluation for film cooling with different winglet pairs vortex generators. Applied Thermal Engineering, 201, 117731. https://doi.org/10.1016/j.applthermaleng.2021.117731.

Halder, N., (2025). Experimental investigation on vortex generator's distance from film cooling hole. Journal of Thermal Science and Engineering Applications, 17(1), 011006. https://doi.org/10.1115/1.4066985.

He, J., Deng, Q. and Feng, Z., (2021). Film cooling performance enhancement by upstream v-shaped protrusion/dimple vortex generator. International Journal of Heat and Mass Transfer, 180, 121784. https://doi.org/10.1016/j.ijheatmasstransfer.2021.121784.

Ito, S., Goldstein, R.J. and Eckert, E.R.G., (1978). Film cooling of a gas turbine blade. Journal of Engineering for Power, 100(3), pp.476–481. https://doi.org/10.1115/1.3446382.

Kelso, R.M., Lim, T.T. and Perry, A.E., (1996). An experimental study of round jets in cross-flow. Journal of Fluid Mechanics, 306, pp.111–144. https://doi.org/10.1017/S0022112096001255.

Khorsi, A., Guelailia, A. and Hamidou, M.K., (2016). Improvement of film cooling effectiveness with a small downstream block body. Journal of Applied Mechanics and Technical Physics, 57(4), pp.666–671. https://doi.org/10.1134/S0021894416040106.

Liu, B., An, J., Zhang, C. and Zhou, S., (2013). Film cooling of cylindrical hole with a downstream short crescent-shaped block. Journal of Heat Transfer, 135(3). https://doi.org/10.1115/1.4007879.

Patankar, S.V. and Spalding, D.B., (1972). A calculation procedure for heat, mass and momentum transfer in three-dimensional parabolic flows. International Journal of Heat and Mass Transfer, 15(10), pp.1787–1806. https://doi.org/10.1016/0017-9310(72)90054-3.

Rigby, D.L. and Heidmann, J.D., (2009). Improved film cooling effectiveness by placing a vortex generator downstream of each hole. Turbo Expo: Power for Land, Sea, and Air, Paper No: GT2008-51361, pp.1161–1174. https://doi.org/10.1115/GT2008-51361.

Shinn, A.F. and Vanka, S.P., (2013). Large Eddy Simulations of film-cooling flows with a micro-ramp vortex generator. Journal of Turbomachinery, 135(3). https://doi.org/10.1115/1.4006329.

Straub, D. et al., (2024). Effects of downstream vortex generators on film cooling a flat plate fed by crossflow. Journal of Turbomachinery, 146(5), 051011. https://doi.org/10.1115/1.4064316.

Versteeg, H.K. and Malalasekera, W., (2007). An Introduction to Computational Fluid Dynamics: The Finite Volume Method. 2nd ed. Harlow: Pearson Education.

Zaman, K.B.M.Q., Rigby, D.L. and Heidmann, J.D., (2010). Experimental study of an inclined jet-in-cross-flow interacting with a vortex generator. 48th AIAA Aerospace Sciences Meeting, Orlando, Florida, 4–7 Jan. https://ntrs.nasa.gov/api/citations/20110016116/downloads/20110016116.pdf.

Zaman, K.B.M.Q., Rigby, D.L. and Heidmann, J.D., (2010). Inclined jet in crossflow interacting with a vortex generator. Journal of Propulsion and Power, 26(5), pp.947–954. https://doi.org/10.2514/1.49742.

Zhang, C. et al., (2020). Experimental and numerical study on the flat-plate film cooling enhancement using the vortex generator downstream for the fan-shaped hole configuration. Journal of Turbomachinery, 142(3), p.031006. https://doi.org/10.1115/1.4046234.

Zhao, Z. et al., (2022). Large eddy simulation of compound angle film cooling with vortex generators. International Journal of Thermal Sciences, 178, 107611. https://doi.org/10.1016/j.ijthermalsci.2022.107611.

Zheng, K. et al., (2021). An experimental study on the improvements in the film cooling performance by an upstream micro-vortex generator. Experimental Thermal and Fluid Science, 127, 110410. https://doi.org/10.1016/j.expthermflusci.2021.110410.