Tests on Compressor Cascades of the NACA 6409 Section

Abstract

Results of the low speed cascade tests on the NACA 6409 section as a compressor blade are presented with the following conclusions : (i) Both stalls on the pressure surface which occurs at a small angle of attack and on the suction surface which occurs at a large angle of attack shift to the larger angles of attack with the decrease in pitch. (ii) Mean total head losses are approximately inversely prortional to pitch and increase with the increase in stagger. (iii) Pressure rise through a cascade increases with increase in turning angle, but saturates to a certain value which depends on stagger, never exceeding 40% of the inlet dynamic pressure. (iv) Experimental turning angles and pressure distributions around a blade agree well with theoretical ones so long as the stagger and the angle of attack are small.