Development of New Two-Component TSP for Cryogenic Testing

Abstract

A two-component TSP for cryogenic wind tunnels has been newly developed to extend the highest working temperature up to 320 K, whereas a conventional single-component cryo-TSP operates in the temperature range from 100 K to 240 K. The two-component cryoTSP includes two luminophores: a Ruthenium complex (Ru(trpy)) and a Europium complex which are very temperature-sensitive in the range of 100 K - 240 K and 220 K - 320 K, respectively. The Ruthenium complex needs blue light and the Europium complex needs UV light to be excited. One can distinguish the two luminophores by illuminating the paint at different wavelengths. In addition, both luminophores emit red light. Therefore, it is possible to use a single camera filter to observe the two luminophores. Verification tests at different wind tunnels proved that the two-component cryoTSP makes ist possible to detect a boundary layer transition line even at room temperatures with a single coating. This means that it is neither necessary to apply another TSP to a model nor to use an IR camera for measurements at room temperatures in a cryogenic wind tunnel. As a result, the two-component cryoTSP enables one to save time and money for testing.