Study of a low-pressure nitrogen plasma boundary layer over a metallic plate

The modeling of a low-pressure nitrogen plasma boundary layer over a flat plate is presented and compared with numerous measurements carried out on this test case. Shortcomings of state-of-the art physical and chemical models are discussed. In particular, wall conditions for a nitrogen plasma over a metallic plate are studied in detail. It is shown that in given flow conditions, the accommodation coefficient of the vibrational mode on the metallic plate is very small. A complex recombination process of N⁺ ions at the wall is proposed to explain the low values of N number densities measured.