Flow field torque analysis and valve plate optimization of butterfly anti-stick bleed valve

The main function of the bleed valve (BV) is to release part of the air from the axial compressor to prevent the aero-engine from stalling and surging. The stuck fault of the BV seriously affects the stable operation and safety of the aero-engine. An anti-stick BV design incorporating an eccentric valve plate is proposed to mitigate the issues of valve sticking caused by contamination particles and deformation. To address the issue of large flow field torque (FFT) during the operation of the anti-stick BV, computational fluid dynamics (CFD) methods were employed to investigate the FFT across various opening angles and flow channel structures. The results indicate that the FFT is primarily induced by the asymmetry of pressure distribution at the surfaces of the valve plate. The main strategies to reduce the FFT resulting from the valve plate structure include increasing the maximum closing angle beta, reducing the valve thickness, and shifting the inlet surface closer to the shaft. The optimized valve plate structure reduces the maximum FFT of the BV by 60.7 %. Experimental testing of the optimized prototype demonstrates significantly improved opening and closing characteristics.