Plasma Injection for Hypersonic Blunt-Body Drag Reduction

The summary of combined experimental and computational investigations is presented for the plasma injection from a hypersonic blunt body for drag reduction. The systematic pursuit addresses all speculated mechanisms that can generate favorable magnetoaerodynamic interactions: the counterflow jet shock aerodynamic interaction, the nonequilibrium thermodynamic and chemical phenomenon, and the electromagnetic-aerodynamic interaction. The computational study was carried out by solving both the three-dimensional and the axisymmetric, mass-averaged, Navier-Stokes equations for counterflow jet interaction. The experimental investigation of the plasma injection was conducted in a nominal Mach 6 open jet, blowdown tunnel. The weakly ionized, counterflow jet generated by a plasma torch has a vibrational temperature of 4400 K, an electron temperature around 20,000 K, and electron number density greater than 3 × 10 12 /cm 3