Temperature Sensitive Paint for Wind Tunnel Models

Many groups have performed nonintrusive, global temperature measurement in hypersonic wind tunnel testing, but technical challenges remain. Most temperature sensitive paints are good within a given range of temperatures and wind tunnel conditions, but do not provide an all-inclusive answer to all the user requirements. Some paints work well in cryogenic applications while others work well at high temperatures. Detailed calibration procedures are required to ensure accurate temperature measurement. Finally, current temperature sensitive paints are not environmentally safe and require a specialized model substrate. To address the current technological limitations of temperature sensitive paints, this proposal looks for a simple but elegant approach to global thermal sensing. This innovative approach investigates available technologies within another industry. It borrows from the electronics industry by taking a COTS (components on the shelf) approach to material and equipment selection. Coatings are available in the electronics industry that are transferable to this application. The in situ coatings described in this proposal have emissivities that will allow for accurate temperature measurement in wind tunnel testing. They will work across the entire temperature range within the wind tunnel environment, be removable, environmentally acceptable and can be located globally on the aero structure. Finally, the solution will be easily workable, with a well defined and cost efficient equipment set, be environmentally acceptable and removable.