AN EXPERIMENTAL INVESTIGATION OF LAMINAR HYPERSONIC CAVITY FLOWS PART II: HEAT-TRANSFER AND RECOVERY FACTOR MEASUREMENTS

摘要

An experimental investigation has been made of the recovery factor and heat-transfer distributions on a set of cone-models incorporating annular cavities. This study is the second part of a two-part program. The first section contianed measurements of the pressure distributions.nThe cone-surface Mach number was 6.5, the free-stream Mach number was 11.2, and all experiments were carried out in helium. All cavity flows were "open", and all heat-transfer tests were in the laminar regime.nThe results show that the recovery factor in laminar, hypersonic cavity flow is almost constant within the cavity and downstream of reattachment, and is very close to the laminar attached-flow value. In the immediate vicinity of reattachment, the recovery factor is slightly higher than this value. (Less than 5%),nThe lowest values of the heat-transfer coefficient are found on the cavity floors, where a minimum of about ten to twenty percent of the attached-flow value is reached. The highest values of the heat-transfer coefficient are in the immediate vicinity of reattachment. An average reattachment heat-transfer coefficient of about three times the basic cone heat-transfer coefficient was measured on one cavity model.nOn one model, the integrated heat-transfer in the separated-flow region was evaluated, and was found to be about 55% of the corresponding attached-flow value, In agreement with Chapman's theory.