Heat Transfer Measurements in Cold Wind Tunnels

摘要

Investigations were performed on instrumentation concepts for the purpose of acquiring heat transfer and recovery temperature measurements on models to be tested in cold wind tunnels. The problem in cold wind tunnels is the recovery and model initial (or ambient) temperature can be of the same level so that the temperature excursion during test is generally negligible. A literature search was performed from which 13 candidate instrumentation concepts were identified for further investigation. Detailed analysis and design efforts were performed on the candidates to identify measurement errors, fabrication, data reduction procedures and costs. Based on technical merit and cost, four sensors were selected for cold wind tunnel applications. These sensors include the 2-D foil (Gardon) and wafer thermopile calorimeters, liquid crystals and thermal phosphors.