Analysis of the Low-Speed Similarity Design Principle for a Compressor S-shaped Duct

A numerical simulation investigation has been carried out to determine the low-speed similarity of the annual S-shaped duct that used to connect the compressor spools of aircraft gas turbine engines. A low-speed modeling method was proposed, and the design criterions that need to be maintained among the low-speed modeling design were analyzed. Compared with the results of the low speed simulation on the proportionally amplified S-duct, both the evolution of the endwall boundary layer and the total pressure loss along the streamwise location of the simulated results on the low-speed modeling S-duct are more coincident with the results of the original high speed case. And the final difference of the total pressure loss between the low-speed modeling S-duct and the original high speed one, i. e., 2. %, is much lower than the total pressure loss difference between the low-speed proportion-ally amplified S-duct and the original high speed one, i. e., 10.9%, which can verify the reliability of the low-speed modeling method. Hence, the proposed low-speed modeling method can be used to conduct experimental investigation of the compressor S-shaped Duct in the low-speed and large-scale situation.