NATIONAL ADVISORY COMMITTEE FOR AERONAUTICS

A transonic axial-flow-compressor rotor was tested w i t h low blade angles. The rotor contained the blades used i n a previous investi&tion, but they were set i n a new rotor disk a t a setting angle 8 closer to the axial direct ion than in the original rotor. Over-all and blade-element performance of the low-blade-angle rotor are given herein. The perform-rotor data. I ance is compared with the original rotor and other t ansonic-compressor A t a corrected speed of 1loo feet per second, the low-blade-angle rotor operated w i t h a re la t ive inlet m c h number of 1.2, a diffusion factor of 0.65, and an axial veloci ty ra t io of 0.71 i n the t i p region (11 percent of the passage height away from the outer W ~ J L L). The meas-ured minirmun loss coefficlent was 0.35, which value falls above EL pre-vious correlation of rotor losses with diffusion factor. Through a com-parison with data fo r three other rotors, the occurrence of high losses was related to a high suction-surface Mach number. These comparison