Wavelet neural network(WNN) was trained with experimental data collected from a variety of literature and then was utilized to study influences of geometries of impeller and diffuser on rotating stall in vaneless diffuser

and the results were presented in graphs.Results show that diffusers with different width ratios exhibit distinct responses to geometry variation

proving that different stall mechanisms exist for wide diffuser and narrow diffuser.The conclusions provide reference to the design of vaneless diffuser.