Scaling Effects for Hydrofoil Testing: Developing a methodology for hydrofoil performance measurements in towing tank

Abstract

The fast development and growing interest in hydrofoils within marine applications have led to an increased demand for testing and verification of foil designs. Testing model scale hydrofoils is not as straightforward as for traditional displacement hull models. Currently, there does not exist a proposed way of scaling down a hydrofoil. This work sheds light on the issues of different scaling effects and proposes a method to perform model scale testing of a hydrofoil. This report is an outcome of a master’s thesis project within Naval Architecture and Aerospace Engineering at Chalmers University of Technology. The project aims to evaluate different scaling effects on a horizontal hydrofoil and develop a feasible methodology to test foil performance in a towing tank. Limiting factors of the towing tank are identified and flow effects relative to submergence depth and testing velocity are investigated in the Computational Fluid Dynamics software STAR CCM+. The results build on a verified solver setup by conducting a turbulence model study. The effects of varying submergence depth and velocity is investigated using a generic profile Eppler 818. The characteristics of a wave is shown to have a significant effect on lift.