Experimental And Numerical Investigation Of Rotating Stall Sepression In Axial Compressor With Casing Plasma Actuation

The present trend in aircraft engine technology toward higher bypass ratios, to achieve lower fuel burn, has resulted in advanced compressor designs with high pressure ratio, high efficiency and wide stable operating range. Compressor blade-tip leakage flow is a large source of loss and affects the stable operating envelope of axial compressor. It is significant to control the tip leakage flow to improve the compressor performance. As a result, there is considerable incentive to develop technologies for alleviating the stall limiting physics associated with tip clearance flow. A great number of passive casing treatments such as circumferential grooves and skewed axial slots have been studied in the past. However, such porous wall treatments usually result in an efficiency reduction commensurate to the stall range extension they provide. And some active control methodologies such as "wiggling" inlet guide vanes, upstream flow injection have been demonstrated to be effective in extending stable operating range of compressors.. However, these technologies impose substantial weight penalties. In this research the effectiveness of plasma actuation using dielectric barrier discharge (DBD) actuators for suppressing stall is investigated. Since there are no moving parts, these actuators are easy to maintain and have small response times. Recently the DBD plasma actuators have been gained an increasing interesting alternative that could be very attractive to aeroengine manufacturers.In this paper, the effectiveness of plasma actuation using DBD actuators for energizing the tip leakage flow and suppressing stall inception is investigated with experiments and numerical studies. Liner-force and electro-static models are developed. Numerical flow simulations are performed to study the effect of the plasma body force on the neutral fluid. Based on the experimental data, a more realistic model is integrated into the commercial computational fluid dynamics code FLUENT to simulate the effects of the plasma. For the experiments, compressor casings with plasma actuators are designed and optimized, with which the effect of the plasma actuators to suppress rotating stall and extend the stable operating range of the compressor is studied. The results from the simulation and the experiments carried out in this paper have practical implications in terms of the application of the proposed plasma actuators for stall suppression in gas turbine engines.1.The effect of the plasma actuations is increasingly obvious with the enhancement of the actuation frequency, the voltage and the maximum charge density. And the maximum induced velocity is found near the edge of the exposed electrode.2. The plasma actuation energized the tip leakage flow and alleviate the condition that the end-wall blockage generation. With a further study, it is found that the actuation effectiveness decreases with increasing compressor speed and that the required actuator strength scales with the speed.3. The plasma injection has a significant impact on the supression rotating stall. And the expansion stabilization effect differs with the plasma actuators parameters.