Aeroelastic Response of Rocket Nozzles Subected to Combined Thrust and Side Loads

Abstract

Lateral nozzle forces are known to cause severe structural damage to any new rocket engine in development during test. While three-dimensional, transient, turbulent, chemically reacting computational fluid dynamics methodology has been demonstrated to capture major side load physics with rigid nozzles, hot-fire tests often show nozzle structure deformation during major side load events. Such deformation leads to structural damages if appropriate structural strengthening measures are not taken. The modeling picture is incomplete without the aeroelastic coupling to address the two-way responses between the structure and fluid. The present work takes into account the aeroelastic coupling for side loads predictions. A loosely coupled method for fluid structural interaction is employed to study the role of the coupling. Two side load cases were computed and are comparatively analyzed for the J-2S nozzle, one case with flexible walls and the other with rigid walls. It is found that aeroelastic coupling has significant effects on the side loads in the nozzle.