Ship Air Wake CFD Comparisons to Wind Tunnel and YP Ship Results (Invited)

Abstract

As part of a project to determine ship air wake impact on naval rotary wing vehicles, this paper compares wind tunnel and computational fluid dynamics (CFD) simulations with in situ data that has been collected on an instrumented United States Naval Academy (USNA) YP (Patrol Craft, Training). The in situ data has been collected underway on a vessel which is 108 ft long and has a 24 ft above water line height. The wind tunnel data is from a 4% scale model tested in the USNA 42 × 60 × 120 inch wind tunnel. CFD simulations were performed on a 15.5 million tetrahedral unstructured grid. Data from the three sources is compared over 11 vertical and horizontal planes above the flight deck on the stern section of the YP. Data is compared for a head wind condition and for relative wind 15° off the starboard bow. Good comparison in velocity direction, typically less than 10-15°, is observed in the vertical and horizontal planes. Normalized velocity magnitudes do not compare as well, likely arising from the lack of an atmospheric boundary layer modeled in CFD simulations and wind tunnel testing.