Pressure sensitive paint (PSP) is a useful noncontact measurement technique to obtain continuous pressure distribution on solid surfaces. The application of PSP to low speed flows in mechanical engineering fields, including unsteady flow measurement related to analysis of aerodynamic noise, is highly demanded. In this study, we clarify the feasibility of PSP as a measurement tool for unsteady low-speed flow fields. Because the response time depends on the square of the thickness of the PSP layer, we have developed the thinner-layer PSP to improve its time response, and the dependence of the thickness of PSP layer on pressure sensitivity and time response was verified. Furthermore we have applied the PSP to measurement of pressure distribution around the circular cylinder in steady flow, to clarify the problems when PSP is applied to measurement of unsteady pressure distribution in low speed flows.
