A nozzle concept to entrain atmospheric air for ejector operation
The purpose of this paper is to describe a design methodology for a converging-diverging nozzle concept that takes advantage of the ejector effect. Incorporating the ejector effect into the nozzle design may be able to provide a more economical means for space transport as thrust increases so fuel quantity can be reduced. Methodology for the proposed nozzle requires three cross sections to be constrained in the diverging portion of the nozzle. The throat maintains axisymmetry with a choked flow condition. A gate is placed between the throat and outlet on the outer perimeter of the nozzle through which the nozzle geometry must pass; however, the shape is given freedom so that it does not have to remain axisymmetric. In doing so, a cutout can be created for air entrainment as the exhaust flow is restricted to flowing through the gate. Finally, the outlet is set to obtain desired rocket exhaust conditions. Viscous effects are accounted for by implementing Edenfield's experimental displacement thickness correlation for turbulent boundary layers.
|14th AIAA/AHI International Space Planes and Hypersonics Systems Technologies Conference|
Cerantola, D.J. (David J.), & Etele, J. (2006). A nozzle concept to entrain atmospheric air for ejector operation. Presented at the 14th AIAA/AHI International Space Planes and Hypersonics Systems Technologies Conference.