Simple Experimental Method to Estimate the Lift of Airfoils

摘要

A method to measure the lift coefficient of an airfoil is presented that requires only the use of two pitot-static tubes or point-velocity measurement devices. The technique could easily be implemented in facilities in which lift estimation is not physically or financially viable to implement using more traditional means. In the method, the pitot-static ports are positioned above and below the airfoil's quarter-chord. The velocity difference between the two tubes is used, via the Kutta-Joukowski theorem, to estimate the sectional lift coefficient. The presence of the upper and lower walls is accounted for using an image system. Comparison with experimental data show excellent agreement between the method and C, estimated by surface-pressure integration.