Application of Pressure-Sensitive Paint for Determination of Dynamic Surface Pressures on a Rotating 65° Delta Wing and an Oscillating 2D profile in Transonic Flow

Abstract

Visualization and measurements of aerodynamic effects on a delta-wing model and a 2D-wing-profile model were conducted using an optical pressure measurement system, based on the pressure-sensitive paint (PSP) technique. The PSP technique can be used to obtain absolute pressure measurements on the surface of a model and in addition to evaluate quantitative aerodynamic flow phenomena by using scientific grade cameras and image processing techniques. The PSP technique has been used here for investigations of periodic and unsteady flows: first, a 65deg delta wing was tested in the transonic wind tunnel DNW-TWG in Gottingen. A specially designed roll apparatus enabled roll rates up to 10 Hz. The experiments were carried out at angles-of-attack up to alpha = 17deg at Ma = 0.8. Since the rotation of the delta wing is a periodic motion, the phase-locked unsteady PSP technique can be applied. In a second wind tunnel campaign in the DNW-TWG in collaboration with the DLR Institute of Aeroelasticity, a 2D-wing-profile model, which is pitch oscillating at up to 30 Hz, was investigated. The experiments were performed at angles-of-attack alpha = 1.12deg plusmn 0.6deg at Ma = 0.72. For these experiments pressure measurements were carried out in one wind tunnel entry by means of both phase-locked unsteady as well as unsteady PSP techniques.