Effect of Leading/Trailing Edge Swept Impeller on Flow Characteristics of Low Specific Speed Centrifugal Compressor

Abstract

A low specific speed centrifugal compressor with leading/trailing edge combined sweep blades is proposed. The performance and internal flow field characteristics are analyzed in detail by numerical simulations, and a bench test is carried out. It is shown that by using the combined leading/trailing edge swept blade, the stage pressure ratio of the centrifugal compressor is improved under all operating conditions, and the maximum increase can reach 6.5%. The efficiency can be markedly improved at high flow rates. Additionally, the leading edge tip leakage is reduced with the combined swept blade, the flow separation on the blade surface is inhibited, and the flow loss of low-energy flow masses downstream of the flow passage is improved. Meanwhile, the combined swept blade can increase the work area of the blade and enhance the work capacity at the blade tip position.