Influence of Flow Speed on the Compression Surfaces of Inlet on Efficiency of the Boundary Layer Bleed

Abstract

The paper presents the results of analytical and experimental study of the bleed coefficient at high flight Mach numbers from 3 to 7. For the calculation, an analytical model was used model with a fixed exit in the supercritical bleed mode, which allows varying the bleed air mass depending on flow conditions and parameter 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 numbers up to 6 and the bleed angles of 90 and 45° were obtained. It is revealed that at increase in the local Mach number, the tendency is observed towards a decrease in the bleed coefficient, and this tendency intensifies with decrease in the bleed channel inclination. These data were used to evaluate known analytical models to determine the characteristics of bleed systems at hypersonic flow velocity analytical models to determine the characteristics of bleed systems at hypersonic flow velocity.