Experimental investigation and numerical verification of Coanda effect on curved surfaces using co-flow thrust vectoring

Year 2021, , 72 - 78, 15.04.2021

Emre Kara Hüdai Erpulat

https://doi.org/10.35860/iarej.758397

Abstract

In this study, a popular co-flow thrust vectoring system, which is superior to typical Coanda nozzles with one main jet, is examined experimentally and compared with 2D and 3D computational fluid dynamics results. High Speed Orienting Momentum with Enhanced Reversibility nozzle concept is the base design to proposed configuration which uses a control jet additional to the main jet for better and active enhancement on the flow vectoring and streamlined side-walls resulted in less flow blockage. This comparatively novel concept is utilized in an experimental setup to direct the thrust of aerial vehicles. The system includes two inlets (inlet1, inlet2) with different jet velocities and one pintle to separate and smoothly direct these jets and a converging-diverging nozzle to enclose these components. Experimental study is accomplished with four different configurations of inlet1 and inlet2 as 15 m/s and 10 m/s; 20 m/s and 10 m/s; 30 m/s and 10 m/s, and 45 m/s and 10 m/s, respectively. The tangential velocities on the curved surfaces are successfully measured utilizing a micro-manometer (Pitot tube) so that attachments/detachments of jets on the exit walls and deflection angles are calculated for each inlet velocities. The current experimental study also revealed that 3D assumption of computational fluid dynamics of Coanda effect is highly accurate and deflection angle results are not far from experimental results with the average deficit of only 5.44 %. As the result, 3D verification study resembles to experimental study in terms of deflection angles for all configurations.

Keywords

Coanda effect, Co-flow thrust vectoring, Computational fluid dynamics, Numerical verification

References

• 1. Trancossi, M. and A. Dumas, ACHEON: Aerial Coanda High Efficiency Orienting-jet Nozzle. SAE Technical Paper, 2011. No. 2011-01-2737.
• 2. Trancossi, M., A. Dumas, S. S. Das, and J. Pascoa, Design methods of Coanda effect nozzle with two streams. Incas Bulletin, 2014. 6(1): p. 83-95.
• 3. Bougas, L., and M. Hornung, Propulsion system integration and thrust vectoring aspects for scaled jet UAVs. CEAS Aeronautical Journal, 2013. 4(3): p. 327–343.
• 4. Newman, B. G., The Deflexion of Plane Jet by Adjacent Boundaries Coanda Effect. 1961, UK: Pergamon Press.
• 5. Jain, S., S. Roy, D. Gupta, V. Kumar, and N. Kumar, Study on fluidic thrust vectoring techniques for application in V/STOL aircrafts. SAE Technical Paper, 2015. No. 2015-01-2423.
• 6. Sidiropoulos, V., and J Vlachopoulos, An investigation of Venturi and Coanda effects in blown film cooling. International Polymer Processing, 2000. 15(1): p. 40-45.
• 7. El Halal, Y., C. H. Marques, L. A. Rocha, L. A. Isoldi, R. D. L. Lemos, C. Fragassa, and E. D. dos Santos, Numerical study of turbulent air and water flows in a nozzle based on the Coanda effect. Journal of Marine Science and Engineering, 2019. 7(2): 21.
• 8. Juvet, P. J. D., Control of high Reynolds number round jets, in Mechanical Engineering 1993, Stanford University: USA, TF-59.
• 9. Trancossi, M., A. Dumas, I. Giuliani, and I. Baffigi, Ugello Capace di Deviare in Modo Dinamico e Controllabile un getto Sintetico senza parti Meccaniche in Movimento e suo Sistema di Con trollo, 2011, Patent No. RE2011A000049, Italy.
• 10. Springer, A., 50 Years of NASA Aeronautics Achievements. 46th AIAA Aerospace Sciences Meeting and Exhibit , p. 859.
• 11. Subhash, M., and A. Dumas, Computational study of Coanda adhesion over curved surface. SAE International Journal of Aerospace, 2013. 6(2013-01-2302): p. 260-272.
• 12. Cen, Z., T. Smith, P. Stewart, and J. Stewart, Integrated flight/thrust vectoring control for jet-powered unmanned aerial vehicles with ACHEON propulsion. Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering, 2015. 229(6): p. 1057-1075.
• 13. Trancossi, M., J. Stewart, S. Maharshi and D. Angeli, Mathematical model of a constructal Coanda effect nozzle. Journal of Applied Fluid Mechanics, 2016. 9(6): p. 2813-2822.
• 14. Panneer, M., and R. Thiyagu, Design and analysis of Coanda effect nozzle with two independent streams. International Journal of Ambient Energy, 2020. 41(8): p. 851-860.
• 15. Kara E., and H. E., Numerical Investigation of Jet Orientation Using Co-Flow Thrust Vectoring with Coanda Effect, in ICAME2019: İstanbul, p. 1-8.