Heat transfer characteristics of film cooled plug nozzle with translating shroud.

The shroud wall temperatures during operation with and without an afterburner are predicted analytically by using a wall heat balance of hot gas radiation, coolant convection, internal and external radiation, and external free convection. The Hatch-Papell film-cooling correlation predicts an adiabatic wall temperature which is used as the driving temperature for the coolant heat transfer. Ejectors with nozzle area ratios from 1.65 to 2. 75 and ejector length to primary diameter ratios from 1.63 to 1.95 were tested. Tests were conducted at nozzle pressure ratios ranging from 2.0 to 6.3, primary total temperatures from 861 to 1939 K (1550 [degree] to 3490 [degree] R), and corrected secondary weight-flow ratios from 0.027 to 0.088. The predictions yielded reasonably good results throughout the range of conditions tested.