Analysis of the Flow Turning Characteristics of Upper-Surface Blowing Devices for STOL Aircraft.

摘要

Experimental data from wind-tunnel tests on the static flow turning performance or upper-surface blown (USB) flaps have been assembled, analyzed, and correlated in the present study. Formulas for calculating the flow turning angle and flow turning efficiency have derived for rectangular nozzles with radius flaps. In the formula for the flow turning angle, the variables are the flap angle, the aspect ratio of the nozzle, the ratio of the flap radius to the nozzle height, and the roof and spread angles of the nozzle. A method for calculating the flow turning angle of arbitrary USB configurations has been outlined. This method accounts by means of parameters for the different geometry of the nozzles, the differences in the flaps, and the effect of installation of USB systems on aircraft. Because of insufficient data base, these formulas have not been completely verified.