Evaluation of Sprayable Unsteady PSP for Application in a Transonic Wind Tunnel

Abstract

A ABSTRACT Two types of sprayable unsteady Pressure-Sensitive Paints (PSP) were applied to wind-tunnel tests of transonic buffeting phenomena on a generic transport aircraft model. One is Gregory's Polymer/Ceramic PSP and the other is a new unsteady PSP consisting of fluoric polymer and TiO2 particles (TU-PSP). Before applying to wind tunnel tests, pressure sensitivity, temperature sensitivity, time response and surface roughness of these PSPs were evaluated. It was found that the mean roughness of TU-PSP were smaller than that of PC-PSP. Also, the sensitivity characteristics of TU-PSP were found superior to those of PC-PSP. In a transonic wind tunnel test, unsteady pressure field on the wing due to buffeting was successfully visualized. However, significant effects of the surface roughness on force and pressure measurements were observed for both PSPs. Further improvements of the paint formulation are needed for application of PSP in development wind-tunnel tests.