Hydrofoil Test Facility at ARL Penn State

The two-dimensional test section of the ARL/Penn State 12-inch water tunnel has been modified to allow a wide range of dynamic tests using hydrofoils. Three examples of test configurations for the hydrofoil test facility are given. These include tests of a single conventional hydrofoil with non-sinusoidal deflections, tests with two hydrofoils for studying tip vortex interactions, and tests of base ventilated supercavitating hydrofoils. When testing a single hydrofoil, the angle of attack can be varied as a function of time using a cam drive system. Arc length Reynolds number of over 1 million based on a 1.5-inch chord are possible. Hydrofoil lift, drag and pitching moment can be measured during transient operation with and without cavitation. Tip vortex interaction studies have been performed by using a second hydrofoil mounted upstream of the primary test hydrofoil. This upstream hydrofoil is inclined to the tunnel wall so only the tip projects in front of the downstream hydrofoil. The upstream hydrofoil can be traversed across the test section to study the tip vortex interactions. Supercavitating hydrofoils have been tested by ventilating behind a wedge installed along the tunnel wall upstream of the hydrofoil. A full range of test instrumentation is used to support the studies, such as LDV, PIV, high speed video, and acoustic measurements.