Abstract: A hybrid rocket engine with a vortex flow field injection system that produces a high-speed sustained vortex flow field is described. The hybrid rocket engine includes a generally cylindrical injection chamber with an inner circumference to comprise an outer edge of a solid propellant grain in the hybrid rocket engine. The engine also includes an injection system that has a throttle valve and an injector that injects injection fluid into the engine and produces a vortex flow-field for the injected fluid. The injector includes at least one primary feed line that distributes the injection fluid throughout a pre-swirl chamber and multiple orifices along an inner edge of the injection chamber. The pre-swirl chamber connects to the injection chamber and at least one of the primary feed lines and redirects a primary fluid flow of the injected fluid from a primary axial direction to a centrifugal direction.

Abstract: A system and method for producing fuel grain for a rocket engine horizontally with an additive manufacturing machine is disclosed. To begin, a fuel grain model is received. The fuel grain model is oriented in a direction of a central core axis and divided into two-dimensional layers with defined footprint areas. In accordance with the fuel grain model, a first layer is printed by applying successive fuel beads in a direction primarily parallel to the central core axis.