Measurement of flow-induced pressures on the surface of a model in a flow visualization water tunnel

Flow-induced pressures were measured on the surface of a delta wing in a flow visualization water tunnel, and at the same time the vortical flow over the wing was visualized using dye. For a free-stream velocity of 0.1 m/s used in the experiments, the pressures were small (less than 15 Pa). This is believed to be the first time that flow-induced pressures have been measured in a water tunnel at such a low velocity. Measured pressure distributions can now be properly interpreted in terms of observed detailed flow patterns, without having to undertake complementary wind tunnel experiments to measure model loading.Symbols   c   centreline chord of the delta wing (c=300.0 mm) - C _p   pressure coefficient on the surface of the delta wing - f   frequency (Hz) - p _ref   static pressure measured by the reference static-pressure probe (Pa) - P _ref   total pressure measured by the reference total-pressure probe (Pa) - p _wing   flow-induced pressure at a pressure tapping on the delta wing (Pa) - R   Reynolds number for the delta wing in water (R=Uc/v _w) - s   local semi-span of the delta wing (mm) - U   free-stream velocity in the test section of the water tunnel (m/s) - x   chordwise distance from the apex of the delta wing (mm) - y   spanwise distance from the centreline chord of the delta wing (mm) -   angle of attack of the delta wing (deg) -   angle of sideslip of the delta wing (deg) - v _w   kinematic viscosity of water (m²/s) - _a   density of air (kg/m³) - _w   density of water (kg/m³)

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L. P. ErmEmail: