Interference Effects of a Strut on the Lift and Drag of a Hydrofoil

The evaluation of performance characteristics of hydrofoil systems employed to support water-borne craft commonly makes use of two-dimensional foil section analysis. Such evaluations are currently in need of more data for handling the contributions of the surfaces in the vicinity of the strut-foil junction where three-dimensional flow-interference effects occur. In this study, towing tank tests were used to evaluate the influence of interference on the lift and drag of selected models of common junction conditions under a variety of submergence, attack, and yaw conditions. The evaluation was made from pressure distribution measurements.