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提出了一种端壁组合射流技术以控制进口马赫数0.67的高速扩压叶栅端区流动。通过前缘射流旋涡可以增强端壁附面层与主流间的流体交换,阻碍横向二次流动,减小角区低能流体堆积;而采用角区射流注入能量能够进一步减弱吸力面侧流动分离。以上组合控制方法可较单独采用前缘或角区射流更有效减小栅内损失,提高其气动性能。当角区射流位于近吸力面侧的分离起始位置附近时,其改善栅内流动的效果最佳;远离吸力面的端壁射流则可抑制端区低能流体横向迁移及其与分离区流体间的相互作用,但其减小损失的效果弱于近吸力面侧的射流。随着射流总压比的增加,组合射流减小损失的效果先增加后减小;过大的总压比会加剧射流与来流间的掺混损失,使得叶栅气动性能恶化。当射流总压比为1.2时,损失减小最大可达12.6%,而射流流量仅相当于叶栅进口流量的0.64%。
A new type of end-wall jet technology is proposed to control the flow of high-speed compressor cascades with an inlet Mach number of 0.67. The vortices of the leading edge jet can enhance the fluid exchange between the endwalls and the main stream, hinder the horizontal secondary flow and reduce the accumulation of the low-energy fluid in the corner area. The injection of the energy into the corner jet can further weaken the flow separation on the suction side. The above combined control method can effectively reduce the in-grid loss and improve the aerodynamic performance more effectively than using the leading edge or corner jet alone. When the jets near the suction side near the separation starting position, the effect of improving the flow in the gate is best. The jet far away from the suction side can restrain the lateral migration of low-energy fluid in the end zone and its interaction with the fluid in the separation zone However, the effect of reducing the loss is weaker than the jet near the suction side. As the total jet pressure ratio increases, the effect of the combined jet to reduce the loss first increases and then decreases. Too large a total pressure ratio will aggravate the mixing loss between the jet and the incoming flow and deteriorate the aerodynamic performance of the jet. When the total jet pressure ratio is 1.2, the loss can be reduced up to 12.6%, while the jet flow rate is only 0.64% of the cascade inlet flow rate.