Flow field characteristics of isolator with fluidic injection
-
Lovaraju Pinnam
,
Ruby Kurapati
Abstract
The present work investigates the effect of secondary fluidic injection on the flow-physics of a supersonic stream within an isolator. An isolator with a length-to-height ratio of 4.5 and an entry Mach number of 2 was chosen for this investigation. The experimental investigations were conducted at a nozzle pressure ratio of 4 and at secondary pressure ratios of 0.75, 1, 1.25 and 1.5. The secondary stream was injected at 0.75 times the length of the isolator, from its inlet. It is inferred that the extent of propagation of disturbances increases with secondary pressure ratio. The single-sided injection causes asymmetry between the pressure distributions along the wall of injection and its opposite side.
-
Research ethics: Not applicable.
-
Informed consent: Not applicable.
-
Author contributions: The author has accepted responsibility for the entire content of this manuscript and approved its submission.
-
Use of Large Language Models, AI and Machine Learning Tools: None declared.
-
Conflict of interest: The author states no conflict of interest.
-
Research funding: None declared.
-
Data availability: The data that support the findings of this study are available on request from the corresponding author.
References
1. Balu, G, Gupta, S, Srivastava, N, Panneerselvam, S, Rathakrishnan, E. Experimental investigation of isolator for supersonic combustion. In: 38th AIAA/ASME/SAE/ASEE joint propulsion conference & exhibit;4134; 2013. https://doi.org/10.2514/6.2002-4134.Search in Google Scholar
2. Dhananjayarao, G, Balu, G, Panneerselvam, S, Rathakrishnan, E. Investigation on isolator performance. In: 39th AIAA/ASME/SAE/ASEE joint propulsion conference and exhibit;4403; 2003. https://doi.org/10.2514/6.2003-4403.Search in Google Scholar
3. Fang, J, Xiao, XY, Fang, GL. Numerical study of shock train in the isolator of scramjet engine. In: IOP Conference Series: Materials Science and Engineering;887:012031; 2020. https://doi.org/10.1088/1757-899X/887/1/012031.1Search in Google Scholar
4. Yun, D, Chun, H, Kim, H, Sung, H-G. Theoretical modelling on three operation modes of a scramjet isolator. Intern J Aeronautical Space Sci 2025;26:162–71. https://doi.org/10.1007/s42405-024-00757-x.Search in Google Scholar
5. Deng, R, Wu, K, Kim, HD, Chen, Q. Effects of isolator length on pseudo-shock wave in a rectangular duct. J Mech Sci Technol 2023;37:209–16. https://doi.org/10.1007/s12206-022-1222-3.Search in Google Scholar
6. Sharma, V, Eswaran, V, Chakraborty, D. The influence of isolator section on the shock augmented mixing in scramjet engine. Aero Sci Technol 2022;130:107900. https://doi.org/10.1016/j.ast.2022.107900.Search in Google Scholar
7. Sethuraman, VRP, Kim, TH, Dong Kim, H. Effects of back pressure perturbation on shock train oscillations in a rectangular duct. Acta Astronaut 2021;179:525–35. https://doi.org/10.1016/j.actaastro.2020.11.057.Search in Google Scholar
8. Sethuraman, VRP, Yang, Y, Kim, JG. The study on interaction of shock train with cavity shear layer in a scramjet isolator. Phys Fluids 2023;35:036111. https://doi.org/10.1063/5.0137481.Search in Google Scholar
9. Huang, T, Zhang, Q, Yue, L, Zhang, P, Zhao, Q. Hysteresis of shock train movement in the isolator with A ramp. AIAA J 2021;59:3873–82. https://doi.org/10.2514/1.J060051.Search in Google Scholar
10. Valdivia, A, Yuceil, KB, Wagner, JL, Clemens, NT, Dolling, DS. Control of supersonic inlet-isolator unstart using active and passive vortex generators. AIAA J 2014;52:1207–18. https://doi.org/10.2514/1.J052214.Search in Google Scholar
11. Geerts, JS, Yu, KH. Systematic application of background-oriented schlieren for isolator shock train visualization. AIAA J 2017;55:1105–17. https://doi.org/10.2514/1.J054991.Search in Google Scholar
12. Kong, C, Zhang, C, Wang, Z, Li, Y, Chang, J. Efficient prediction of supersonic flow field in an isolator based on pressure sequence. AIAA J 2022;60:2826–35. https://doi.org/10.2514/1.J061375.Search in Google Scholar
13. Redding, J, Cavanaugh, E, Bravo, L, Murugan, M, Narayanaswamy, V. Investigation of scramjet inlet unstart/restart behavior induced by high angle of attack and dynamic isolator camber motion. Phys Fluids 2025;37. https://doi.org/10.1063/5.0271076.Search in Google Scholar
14. Wang, Y, Chen, F, Tian, Z, Fu, A, Yao, Y, Shi, L, et al.. Shock train stabilization by A high-speed jet injection in an inlet isolator of A ramjet engine. Phys Fluids 2025;37. https://doi.org/10.1063/5.0268520.Search in Google Scholar
15. Petha Sethuraman, VR, Kim, TH, Kim, HD. Shock train control by boundary layer suction in A scramjet isolator. Proc Inst Mech Eng G J Aerosp Eng 2020;235:1211–24. https://doi.org/10.1177/0954410020967537.10.Search in Google Scholar
16. Yun, D, Chun, H, Kim, H, Sung, HG. Theoretical modeling on three operation modes of a scramjet isolator. Intern J Aeronautical and Space Sci 2025;26:162–71. https://doi.org/10.1007/s42405-024-00757-x.Search in Google Scholar
17. Inturi, DM, Pinnam, L, Raju Vegesna, R, Rathakrishnan, E. Effect of secondary fluid injection on flow through supersonic nozzle. J Visual 2024;27:1049–58. https://doi.org/10.1007/s12650-024-01013-w.Search in Google Scholar
© 2025 Walter de Gruyter GmbH, Berlin/Boston
