Unsteady and Quasi-Steady Modes of the Flow Over an Intake Tested in a Hotshot Wind Tunnel
Yu. P. Gounko, I. V. Kavun
Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
Keywords: hotshot wind tunnel, tests of air intakes, axisymmetric intake with internal compression, unsteady and quasi-steady modes of the flow over the intake, pulsing flow mode
Abstract
Results of a numerical simulation of an unsteady flow in an axisymmetric intake with internal compression tested in a hotshot wind tunnel with a fixed-volume settling chamber are discussed. The present simulations reveal the main features of various modes: unsteady processes of wind tunnel and intake starting, quasi-steady flow over the started intake with a supersonic flow velocity in the intake duct, and subsequent ulterior transition to the flow with a detached bow shock wave in front of the air intake with a subsonic flow velocity in the duct. A previously unknown mode of the flow over the intake with pulsing motion of the bow shock wave is observed. It is shown that pulsations decay with time, and the bow shock wave position in the incoming flow becomes stabilized at a certain distance from the leading edge of the intake with the test flow in the wind tunnel being preserved.
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