Abstract:Supersonic inlets are a key component of present and future air-breathing propulsion systems for high-speed flight. The inlet design is challenging because of several phenomena that must be taken under control: shock waves, boundary layer separation and unsteadiness. Furthermore, the intensity of these phenomena is strongly influenced by the working conditions and so active control systems can be particularly useful in off-design conditions. In this work, a mixed compression supersonic inlet with a double wedg… Show more
“…This combined approach is anticipated to yield enhanced effectiveness. Other studies have combined the bleed system with other flow control methods, such as vortex generators [122], plasma injection [123], mesoflap [124] and cavity [125]. For the second problem, recent studies [126][127][128][129] have examined a new bleed system design, mostly in steady-state conditions, consisting of multiple parallel slots.…”
High-speed air intakes often exhibit intricate flow patterns, with a specific type of flow instability known as `buzz’, characterized by unsteady shock oscillations at the inlet. This paper presents a comprehensive review of prior research, focused on unraveling the mechanisms that trigger buzz and its implications for engine stability and performance. The literature survey delves into studies concerning complex-shaped diffusers and isolators, offering a thorough examination of flow aerodynamics in unstable environments. Furthermore, this paper provides an overview of contemporary techniques for mitigating flow instability through both active and passive flow control methods. These techniques encompass boundary layer bleeding, the application of vortex generators, and strategies involving mass injection and energy deposition. The study concludes by discussing future prospects in the domain of engine-intake aerodynamic compatibility. This work serves as a valuable resource for researchers and engineers striving to address and understand the complexities of high-speed air induction systems.
“…This combined approach is anticipated to yield enhanced effectiveness. Other studies have combined the bleed system with other flow control methods, such as vortex generators [122], plasma injection [123], mesoflap [124] and cavity [125]. For the second problem, recent studies [126][127][128][129] have examined a new bleed system design, mostly in steady-state conditions, consisting of multiple parallel slots.…”
High-speed air intakes often exhibit intricate flow patterns, with a specific type of flow instability known as `buzz’, characterized by unsteady shock oscillations at the inlet. This paper presents a comprehensive review of prior research, focused on unraveling the mechanisms that trigger buzz and its implications for engine stability and performance. The literature survey delves into studies concerning complex-shaped diffusers and isolators, offering a thorough examination of flow aerodynamics in unstable environments. Furthermore, this paper provides an overview of contemporary techniques for mitigating flow instability through both active and passive flow control methods. These techniques encompass boundary layer bleeding, the application of vortex generators, and strategies involving mass injection and energy deposition. The study concludes by discussing future prospects in the domain of engine-intake aerodynamic compatibility. This work serves as a valuable resource for researchers and engineers striving to address and understand the complexities of high-speed air induction systems.
“…As the flight speed range increases, it is difficult to coordinate the low-speed starting performance and the high-speed cruising performance of the ramjet, which seriously restricts the engine performance improvement [1]. In order to improve the inlet performance, many studies have been carried out on various active and passive flow control methods, such as boundary layer suction [2,3], plasma [4][5][6], vortex generators [7][8][9][10], and so on. These flow control methods could improve the shock wave/boundary layer interference and other flow field characteristics, and improve the inlet performance to a certain extent.…”
According to the requirements of a wide speed range, a variable-geometry supersonic inlet with inner surface adjustment is studied. The basic design model of the inlet is established, and the influence of profile adjustment on the resisting back pressure ability and inlet performance boundary are analyzed using a theoretical method. Based on the numerical simulation method, the flow field simulation is carried out, and the flow field parameter distribution and performance of the adjustment inlet are studied in comparison with the fixed-geometry scheme. The results show that the starting Mach number is not changed for two inlet schemes because they have the same profile during low-speed flight. The fixed-geometry inlet has insufficient compression on the incoming flow, and the resisting back pressure ability decreases significantly during high-speed flight. The compression ratio and the compression wave system can be easily changed at the same time through the adjustment of the inner profile for the adjustable inlet during high-speed flight. Both the theoretical analysis and numerical simulation show that the resisting back pressure ability and performance are significantly improved after the adjustment. As such, the adjustment method in this paper can fundamentally solve the problem of the insufficient compression of the wide-range working inlet during high-speed flight, and the method can be easily realized.
“…There are two broad control methods, 5 active and passive. Active methods are those, which can be controlled after the installation, such as bleed, 6,7 actuators, 7 microjets, 8 heat sources, 9 particle momentum transfer, 10 boundary layer suction and blowing, 11 and so forth. On the other hand, passive methods are which cannot be controlled, such as vortex generators (VGs), 12 bumps, 13 air-jet vortex generators (AJVGs), 14 aeroelastic mesoflaps, 15 surface morphing, 16 porosity, 17 and a new control method "backward-facing step."…”
Section: Introductionmentioning
confidence: 99%
“…Effect of backpressure over ramp surface for clean model (top: pressure distribution, bottom: Mach number)7.25, the position of this terminal normal shock wave changes and it shifts towards the entry of the air intake. The terminal shock wave appears approximately at X/L = 0.49, 0.28, and 0.15 for BPR of 5, 6, and 7.25, respectively.…”
The present investigation is aimed towards the effect of passive methods on the performance of supersonic air intake along with the control of shock wave boundary layer interaction at various engine operating conditions. A computational study has been carried out in this regard using the commercially available software Ansys Fluent. The k-ω turbulence model has been selected for the present investigation. All the simulations have been carried out at a design Mach number of 2.2. The Independent effect of the air-jet vortex generator (AJVG), tapered micro ramp vortex generator (MRVG), and the combined effect of AJVG with MRVG on the shock wave boundary layer interaction have been investigated. Detailed comparative studies of all controlled cases with uncontrolled cases show significant improvement in the flow field inside the air intake and improved performance. The shock train is also captured for all the cases along with shock wave boundary layer interaction at various operating conditions. The movement of the normal shocks is seen as the backpressure increases. All the essential performance parameters related to air intake have been examined in detail. The hybrid type of control showed better performance.
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