An Experimental Investigation of Laminar Hypersonic Cavity Flows. Part 2. Heat Transfer and Recovery Factor Measurements

An experimental Investigation has been made of the recovery factor and heat-transfer distributions on a sot of cone-models incorporating annular cavities. This study is the second part of a two-part program. The first section contlaned measurements of the pressure distributkons. The cone-surface Mach number was 6.5, the free-stream Mach number was 11.2, and all experiments were carried oui In hellum. All cavity flows were "open", and all heat-transfer tests were In the laminar regime. The results show that the recovery factor In laminar, hyporsonic cavity flow Is almost constant within the cavity and downstream of ruattachment, and Is very close to the lamilnar attached-flow valuu. In the immedlate vicinity of roattachment, the recovery factor is slIghtly higher than this value. (Less than ý%). The lowost values of the heat-transfer coefficient are found on the cavity floors, whore a minimum of about ten to twenty percent of thQ attached-flow vulue Is reached. The highest values of the heattransfer coefficient are in the Immediate vicinity of reattachment. An average reattachment heat-transfer coefficient of about three Ilmos the basic cone heat-transfer coefficient was measured on one cavity modul. On one model, the Integrated heat-transfer In thu sparatod-flow region was evuluuted, and was found to be about 55% of the corresponding attached-flow value, In agreement with Chapman's fhuory.