CRYSTAL camera, an infrared instrument for flow visualization between 90 and 313 K has been installed in a cryogenic wind tunnel

摘要

ONERA (Office National d'Etudes et de Recherches Aeospatiales (Chatillon, France)) has developed an IR camera prototype named CRYSTAL (Cryogenic System for Thermographic analysis of Aerodynamic Layer) to perform surface flow visualisation at cryogenic temperatures in the severe environment of ETW GmbH (European Transonic Windtunnel (Cologne, Germany).) The camera, which has been operating since 1998, is based on a 128×192 Si:Ga focal plane array (developed by LETI/LIR/CENG) and is, to our knowledge, the first world-wide IR camera to work in a cryogenic wind tunnel and at such temperatures. Indeed, the working temperature of the tunnel varies between 313 K and 90K. The qualitative thermometry of CRYSTAL from the ambient reaches down to 120 K. The aerodynamic effects to observe need a level of resolution inferior to 1 K. This paper addresses the mechanical aspects of the instrument.