Plasma Jet for Flight Control

The need for high-speed flight-control devices has surged with recent interest in hypersonic flight. Plasma-based devices offer actuation times that are orders of magnitude smaller than conventional mechanical actuators. The plasma jet, which uses energy deposition to generate a high-speed jet, is evaluated for flight control. The jet is created by pulsing a cavity with energy deposition. The gas expands through a converging nozzle, inducing a jet flow. This research focuses on characterizing the forces generated by a single pulse of the plasma jet, assuming energy is deposited uniformly throughout the cavity and the jet exits to quiescent flow. A one-dimensional analytical model is developed to predict the force and impulse generated by the jet as well as the temporal evolution of the pressure, density, and temperature in the cavity. A relation between the dimensionless energy deposition and the dimensionless impulse is developed and verified with computational results. It is shown that the dimensionless impulse generated by the jet is essentially independent of the dimensionless geometric parameters of the cavity. Additionally, a simplified analysis shows that the force from an array of plasma jets is sufficient to replace a conventional aerodynamic flap.