Correlation of solidity, aspect ratio and compound lean blade in compressor cascade design

Compressor one-dimensional design prediction models provide match basis of cascade design parameters. Solidity and aspect ratio are two primary prediction parameters. Compound lean blade is a three-dimensional blade technology generally applied in compressor redesign. This paper analyzes the correlations of solidity, aspect ratio and compound lean blade in order to find compound lean blade effect on cascade design. Abundant cascade cases have been computed by proved numerical method. Characteristics of compound lean blade effect on diffusion and loss are discussed. To exploit the dependence of geometry and performance parameters under min-loss working condition, a minimum loss incidence (i(o)) model, a diffusion factor (D-o) model and a total pressure loss (omega(o)) model are built up, and dependence map of parameters is analyzed. It suggests that compound lean blade changes constraint relations between parameters and enriches the choices of design case. Finally, a minimum loss model (omega(theta),(Do))(min) and a minimum blade count model (h/t(theta),(Do))(min) are studied, providing new parameter match principles and selection range, which breaks through traditional parameters balance relationship established based on straight blade. So, there is reasonable prediction that introducing compound lean blade to prediction models could broaden compressor one-dimensional design view and contribute to compressor optimal design.