Influence of Surface Sublimation on Supersonic Boundary Layer Properties

Abstract
The paper presents results of theoretical investigation of characteristics of the supersonic Mach = 2 flat-plate boundary-layer under conditions of surface sublimation in the flow of air. Naphthalene (C₁₀H₈) is used as a sublimation material. Calculations found that with increasing surface temperature, the mass flow rate of naphthalene evaporation also increases. In this case, the total heat flux to the solid wall decreases, while its temperature decreases also in comparison with the case of a flow past a flat-plate without sublimation. Large molecular weight of naphthalene in comparison with molecular weight of air and lowering of the surface temperature as a result of the wall material evaporation lead to an increase in the density of the binary mixture (air and vapor of the sublimation substance) near the wall, that can lead to an increase in the stability of the supersonic boundary layer and to a delay in its transition to turbulence.

Keywords
supersonic boundary layer, laminar-turbulent transition, binary gas mixture, sublimation
Acknowledgements
The research was carried out within the framework of the Program of Fundamental Scientific Research of Russian state academies of sciences in 2013-2020 (project АААА-А17-117030610125-7, no. 0323-2018-0009) and was also supported by Russian Foundation for Basic Research (project 18-01-00070а) 
УДК 532.526

Influence of Surface Sublimation on Supersonic Boundary Layer Properties