Estimating aerofoil lift from flow angle

An analytic method is developed to estimate the lift developed by an aerofoil using measurements of flow angularity aft of the aerofoil. The Kutta-Joukowski theorem is used to relate the measured flow angle to the circulation generated by the aerofoil. A correction for the effect of the walls is also developed. Comparison of the flow angle estimated lift compared with that measured using a force balance showed close accord. Ten terms in the series yield an error less than 0.2% compared to the limit for this expression, while five terms yields an error less than 1%.