返回Google圖書搜尋

Effect of Critical Mach Number and Flutter on Maximum Power Loading of Ducted Fans

Arthur A. RegierJohn G. BarmbyHarvey H. Hubbard

出版	National Advisory Committee for Aeronautics, 1947
URL	http://books.google.com.hk/books?id=B-bmtgAACAAJ&hl=&source=gbs_api

註釋Flutter tests were made of two wind-tunnel-fan models, one of which had conventional Clark Y airfoil sections and the other of which had high-camber blade sections. The results of the tests confirm the stall-flutter theory which predicts much higher flutter speeds at the high lift coefficients for the high-camber blades. The high-camber blades could, therefore, be operated at much higher power loadings than could the low-camber blades. Aerodynamic data of these tests indicated little difference in efficiency for the two fans but somewhat higher maximum lift coefficient for the high-camber fan. The efficiency of the fans decreased after the velocity, as calculated by two-dimensional theory, exceeded the speed of sound on the upper blade surface.