Nonequilibrium laminar boundary-layer flow of ionized air

Numerical calculations of the nonequilibrium ionized air boundary layer on a cone-shaped re-entry vehicle at several flight conditions are determined with a finite-difference scheme. The results of this investigation show that the electron density 15-ft downstream on a cone at re-entry velocity is approximately 10 electrons/cm at 150,000-ft alt, whereas at 100,000 ft, the value has increased to 10 electrons/cm. This investigation also shows the importance of considering the nonequilibrium aspects of the flow rather than the limiting cases of frozen or equilibrium flow. The study of the chemical reactions shows that atomic oxygen is mainly produced from the dissociation of molecular oxygen, whereas atomic nitrogen results mainly from two of the shuffle reactions. The production of nitric oxide comes from the shuffle reactions. For distances up to 15-ft downstream from the tip and for conditions considered, none of the chemical reactions are near equilibrium.