control with energy addition Virtual shapes in supersonic flow

This paper presents a short selective review of theoretical and experimental studies conducted by the authors and their collaborators during the past few years in areas related to supersonic and hypersonic flow regimes with applications such as drug reduction, inlet and effective vehicle geometry control in off-design flight regimes, and steering and sonic boom mitigation. Their results suggest a principal possibility to enable transitions between the propulsion modes and ramjet startup and to minimize the need for the traditional isolator stage, as well as to increase the inlet mass capture at Mach numbers below the design value, using active control based on virtual shapes created by energy addition upstream of the inlet throat. A common feature of all these substantially different applications and processes is a power deposition into a supersonic flow which results in the creating of virtual shapes, modifying flowlike solid obstacles immersed in it. The virtual shapes can be created by microwave plasma heating, magnetohydrodynamic forces, electron beams, and localized plasma-assisted surface combustion. The power necessary to operate plasmas can come either from the turbine at mode transition, from an auxiliary power unit, or, as suggested in a new bypass concept, from a magnetohydrodynamic generator either placed downstream of the combustor or collocated with it. Copyright 2008 by Princeton University.

Virtual shapes in supersonic flow, control with energy addition