Plasma Aerodynamics: Current Status and Future Directions

Plasma aerodynamics can trace its origin to the beginning of the space age, and in particular to a time when designers realized that plasmas could have a significant influence on reentry flows. From the 1950s to the 1970s, there was considerable work on magnetohydrodynamic reentry systems and related technology. The recent resurgence in the field was stimulated by the disclosure of the Soviet AJAX vehicle concept in the mid-1990s. This led to an extraordinary international collaboration that has now lasted almost twenty years. Plasma-based flow control seems quite feasible, particularly
for local flow control applications where power consumption is low. Plasma-based devices have a low profile, and can provide actuation over short time scales. Plasmaenhanced combustion is a very promising area for both low- and high-speed regimes. Discharges are already being used to break down fuels, enhance ignition, provide flameholding, and promote combustion efficiency. There are a number of potential breakthrough areas in the field that could have strong technological impact on the aerospace industry. Industry seems to be receptive to the adoption of plasma-based technology, but has reservations about technical risk, performance, reliability, and integration. There is a need to identify applications where plasma devices are significantly better than completing technologies, and to demonstrate prototypes in an operational environment. With a century of atmospheric flight and half a century of spaceflight behind us, the aerospace sciences remain a vigorous and exciting field. The new field of plasma aerodynamics contributes to this excitement, and supports diverse aerospace technology needs, from energy efficiency to space access.