Dual bell nozzle permits two different operating modes, which provide higher performance than conventional bell nozzles, when applied to rocket engines operating in a varying ambient pressure environment. The configuration of a dual bell nozzle in the cryogenic engine of the Ariane 5 main stage, could be based on the injection of the turbine exhaust gases in the nozzle, to increase the thrust and to cool the wall. The effectiveness of the film cooling is evaluated by a parametric study and in particular, the effect of the secondary gas injection on the overall flow behavior is studied because of its possible effect on one of the most critical aspects of dual bell nozzles, the side loads, that may occur during the separated flow operations and during the transition between the two operating modes.
Film Cooling in Dual-Bell Nozzles / Nasuti, Francesco; E., Martelli; Onofri, Marcello; E., Pietropaoli. - 563:(2004), pp. 459-464. ( 5th European Symposium on Aerothermodynamics for Space Vehicles Colonia, Germania 8-11 novembre 2004).
Film Cooling in Dual-Bell Nozzles
NASUTI, Francesco;ONOFRI, Marcello;
2004
Abstract
Dual bell nozzle permits two different operating modes, which provide higher performance than conventional bell nozzles, when applied to rocket engines operating in a varying ambient pressure environment. The configuration of a dual bell nozzle in the cryogenic engine of the Ariane 5 main stage, could be based on the injection of the turbine exhaust gases in the nozzle, to increase the thrust and to cool the wall. The effectiveness of the film cooling is evaluated by a parametric study and in particular, the effect of the secondary gas injection on the overall flow behavior is studied because of its possible effect on one of the most critical aspects of dual bell nozzles, the side loads, that may occur during the separated flow operations and during the transition between the two operating modes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
