Influence of flow conditions on compression surfaces of hypersonic inlet on characteristics of boundary layer bleed

The paper presents the results of analytical and experimental study of the bleed coefficient at flight Mach numbers from 3 to 7. For the calculation, a calculation model with a fixed exit in the supercritical bleed mode was used, which allows varying the bleed air mass depending on flow conditions and parameter of the bleed system. The measurement of the bleed flow coefficients were performed for three bleed configurations in a wind tunnel at local Mach numbers in front of the bleed area from 2.5 to 5.96. The model had a long forebody, so that before the bleed area there was a thick boundary layer. As a result, new experimental data on bleed coefficient and its general dependence on the Mach number of up to 6 and the bleed angles of 90° and 45° were obtained. It is revealed that at an increase in the local Mach number, the tendency towards a decrease in the bleed coefficient is observed, and this tendency becomes more intensive with a decrease in the bleed channel inclination. These data were used to evaluate known analytical calculation method to determine the characteristics of bleed systems at hypersonic flow velocity.