Control of a Supersonic Inlet in Off-Design Conditions with Plasma Actuators and Bleed

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 wedge ramp is considered. The flow field was numerically investigated at different values of Mach number. The simulations show that large separations appear at the higher Mach numbers on both the upper and lower walls of the duct. In order to improve the performances of the inlet two different control strategies were investigated: plasma actuators and bleed. Different locations of the plasma actuator are considered in order to also apply this technology to configurations with a diverter which prevents boundary layer ingestion. The potential of the proposed solutions is investigated in terms of total pressure recovery, flow distortion and power consumption.

Aerodynamic Instabilities in High-Speed Air Intakes and Their Role in Propulsion System Integration

“…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.…”

Study on a Two-Dimensional Supersonic Inlet with Inner Profile Adjustment

“…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.…”

Control of shock‐induced separation inside air intake by vortex generators

“…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."…”

“…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.…”