Wavy leading edge amplitude effects on performance in a single-stage transonic axial flow compressor

Aiming at the problem that the mechanism of how the amplitude parameter of the wavy leading edge profile affects the performance of transonic compressors remains unclear, this paper takes a single-stage transonic axial flow compressor as the research object and designs four schemes of different amplitudes of the wavy leading edge of the stator blades. Numerical calculations demonstrate that when the amplitude of the wavy leading edge is set to 5.5% of the axial chord length of the stator blade, the efficiency and the total pressure ratio of the compressor exhibit absolute increases of 0.71% and 0.75%, respectively, under near-stall conditions. It is further observed that when the amplitude of the wavy leading edge is within the range of 5.5%-7% of the axial chord length of the stator blade, the effect of improving the total performance of the compressor becomes more pronounced. When the amplitude of the wavy leading edge is small, the low-pressure region at the leading edge of the stator blade concentrates at the wave crest. The induced leading edge vortex pair has low intensity, which can only suppress airflow separation to a limited extent. As the amplitude of the wavy leading edge increases, the low-pressure region in the wave crest area migrates toward both sides of the wave trough. Under the action of the circumferential and radial pressure gradients, a high-intensity leading edge vortex pair is induced to suppress the spanwise vortex in the corner area and the secondary flow.