SUPERSONIC COMBUSTION ENHANCEMENT BY A NONEQUILIBRIUM PLASMA JET

IT IS PROPOSED TO DETERMINE THE FEASIBILITY OF USING A NONEQUILIBRIUM PLASMA JET, DEVELOPED AT AEROCHEM OVER THE PAST QUARTER CENTURY, AS A MEANS OF ENHANCING IGNITION AND FLAME STABILIZATION IN AIR-BREATHING ENGINES AND IN SUPERSONIC COMBUSTION. SPECIFICALLY, WE WILL DETERMINE; IF IGNITION OF LEAN OR LOW PRESSURE MIXTURES CAN BE MADE MORE RELIABLE; IF FLAME HOLDING LIMITS CAN BE BROADENED, E.G., TO LEANER MIXTURES OR TO HIGHER VELOCITIES; OR IF THE CLASSICAL MECHANICAL FLAME-HOLDER CAN BE REPLACED OR AUGMENTED BY A SUPERSONIC JET CONTAINING A HIGH DEGREE OF NONEQUILIBRIUM EXCITATION AND DISSOCIATION. THE AEROCHEM NONEQUILIBRIUM PLASMA JET IS PRODUCED BY PASSING A GAS, E.G., O2, H2, OR AIR THROUGH A GLOW DISCHARGE AND EXPANDING IT THROUGH A NOZZLE TO PRODUCE A SUPERSONIC STREAM. TYPICALLY, 30% OF THE ENERGY INPUT IS UTILIZED TO DISSOCIATE THE FEED GAS, PRODUCING A 1-4% CONCENTRATION OF ATOMS AT A STATIC TEMPERATURE OF LESS THAN 1000 K IN A MACH 3 STREAM. THE MACH NUMBER SHOULD BE READILY EXTENDED. THIS NONEQUILIBRIUM PLASMA JET SHOULD NOT BE CONFUSED WITH THE USUAL PLASMA JET BASED ON AN ARC WHERE THE CHEMICAL COMPOSITION IS DETERMINED BY EQUILIBRIUM AT A VERY HIGH TEMPERATURE, E.G., 3000 TO 4000 K TO OBTAIN THE ABOVE DEGREE OF DISSOCIATION AND EXCITATION.