Delay of Rotating Stall in Compressors Using Plasma Actuators

Abstract

Rotating stall is a well-known aerodynamic instability in compressors that limits the operating envelope of aircraft gas turbine engines. An innovative method for delaying the most common form of rotating stall inception using an annular DBD (Dielectric Barrier Discharge) plasma actuator had been proposed. A DBD plasma actuator is a simple solid-state device that converts electricity directly into flow acceleration through partial air ionization. However, the proposed concept had only been preliminarily evaluated with numerical simulations on an isolated axial rotor using a relatively basic CFD code. This paper provides both an experimental and a numerical assessment of this concept for an axial compressor stage as well as a centrifugal compressor stage, with both stages being part of a low-speed two-stage axial-centrifugal compressor test rig. The two configurations studied are the two-stage configuration with a 100 mN/m annular casing plasma actuator placed just upstream of the axial rotor leading edge, and the single-stage centrifugal compressor with the same actuator placed upstream of the impeller leading edge. The tested configurations were simulated with a commercial RANS CFD code (ANSYS CFX) in which was implemented the latest engineering DBD plasma model and dynamic throttle boundary condition, using single-passage multiple blade row computational domains. The CFD simulations indicate that in both types of compressors the actuator delays the stall inception by pushing the incoming/tip clearance flow interface downstream into the blade passage. In each case, the predicted reduction in stalling mass flow matches the experimental value reasonably well.

Effect of in-service burnout effect on the transonic leakage flows over cavity tip model

“…One approach is using active flow control techniques such as using plasma actuators. Saddoughi et al 17 studied the tip clearance flow in a transonic compressor with and without plasma actuators and Ashrafi et al 18 investigated the effect of the actuator plasma on the delaying the rotating stall in compressors. Blowing air from the tip or casing wall is another type of active control techniques that can be applied to reduce the tip leakage flows.…”

Effect of casing aspiration on the tip leakage flow in the axial flow compressor cascade

“…Generally, the geometrical modification always works among the whole operating range for passive flow control methods, such as casing treatment, 19–23 blade tip modifications, 24–27 and blade tip winglet, 28–30 which may result in a reduction of performance near design point. While the active flow control can be imposed on the flow fields flexibly either all the time or only when the compressor’s operating point moves dangerously close to the stall line, such as plasma actuation, 31–33 tip injection, 34–38 and aspiration/suction techniques. 39–44 At present, the researches about aspiration mainly focus on the control of the boundary layer separation on blade SS or the 3D separation in the hub corner, 45–50 and the results show that the performance of compressor cascade can be improved significantly by applying the suction method.…”