Dual bell nozzles represent a possible solution to improve performance of large liquid rocket engines for launcher first stages. The present paper studies the role of the second bell shape on the side loads that may occur during the transition between the two main operating modes of the nozzle. In particular, the design of the second bell profile is critically discussed on the base of the results of suitable test cases. The analysis of performance and behavior during the transition is carried out by a validated turbulent Navier-Stokes solver. The results indicate that slightly different geometries designed by the method of characteristics yield slight differences in terms of performance but a different level of safety in the transition phase.
Role of Wall Shape on the Transition in Dual-Bell Nozzles / Nasuti, Francesco; Onofri, Marcello; E., Martelli. - (2003). (Intervento presentato al convegno 39th AIAA/ASME/SAE/ASEE Joint Propulsion Conference tenutosi a Huntsville, AL; United States nel 20-23 luglio 2003).
Role of Wall Shape on the Transition in Dual-Bell Nozzles
NASUTI, Francesco;ONOFRI, Marcello;
2003
Abstract
Dual bell nozzles represent a possible solution to improve performance of large liquid rocket engines for launcher first stages. The present paper studies the role of the second bell shape on the side loads that may occur during the transition between the two main operating modes of the nozzle. In particular, the design of the second bell profile is critically discussed on the base of the results of suitable test cases. The analysis of performance and behavior during the transition is carried out by a validated turbulent Navier-Stokes solver. The results indicate that slightly different geometries designed by the method of characteristics yield slight differences in terms of performance but a different level of safety in the transition phase.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
