On stability of the supersonic boundary layer with a foreign gas injection

Supersonic boundary layer under foreign gas injection and its stability

“…The most important parameters influencing the mixture dynamics are: 2 1 , m m -molecular masses and 2 1 , p p C C -constant pressure specific heats of the primary and foreign gases respectively. From these general equations the system describing 2D stationary supersonic flat-plate boundary-layer of binary gas mixture in the absence of chemical reactions have been deduced in [5] in the approximation of local self-similarity. These equations take into account the foreign gas diffusion across the boundary layer, its thermal diffusion and action of streamwise pressure gradients.…”

“…Foreign gas with molecular mass 1 m is injected into the main flow of the primary gas with a molecular mass 2 m through a permeable surface of the model. For that case boundary layer equations have been written and presented in [9,10].…”

“…Shooting technique and Newton-Raphson iterations to satisfy the boundary conditions have also been used. Boundary layer equations, boundary conditions and numerical technique used in the present investigation is presented in a more detail in [5].…”

“…All physical properties of SF6 necessary for computations in the framework of kinetic theory, such as parameter characterizing molecular collision cross-section, depth of potential well, specific heat have been found in literature and are given in tables in our earlier papers [5,7,8] where one can also find a comparison with similar parameters for other available gases.…”

“…In our previous papers [5][6][7][8] we presented linear stability theory (LST) of the supersonic boundary layer of binary mixtures arising as a result of an injection of various foreign gases into the flow of air through a permeable, for example, porous surface. Detailed investigations have shown, that injection of a heavy gas stabilizes the boundary layer by modifying boundary layer profiles in such a way that flow becomes more stable.…”