The effect of periodic heat transfer on the structure of supersonic turbulent flow in a channel with sudden expansion
I.R. Vasnev, N.N. Fedorova
S.A. Khristianovich Institute of Theoretical and Applied Mechanics, Siberian Branch of the Russian Academy of Sciences, Novosibirsk, Russia
Keywords: Numerical modeling, high-speed flow, turbulence, conjugate heat transfer, periodic heat input, separated flow, flow control
Abstract
This paper presents the results of numerical modeling of the effect of periodic volumetric heat release on the structure of supersonic turbulent flow in a flat channel with a step and the associated heat transfer with heat flux sensor elements embedded in the walls. The modeling is based on the Reynolds-averaged Navier-Stokes equations, supplemented by the k-ω SST turbulence model. The source power was varied harmonically with a period of 10 ms, and the oscillation amplitude was varied while the average power remained constant. It was established that the flow enters a periodic regime with a pronounced relaxation delay. During the phase of maximum heat input, an upstream shift in the wave structure and the formation of local subsonic zones in the flow core are observed. It is shown that periodic power variations influence local heat transfer. For a plate located in the expanding section of the channel, the periodic regime leads to more intense heating than with a constant source of the same average power. A nonmonotonic dependence of the integral heat flux on the oscillation amplitude was discovered. The maximum heat load is achieved at an intermediate, rather than maximum, heat input amplitude, which is explained by the dynamics of shock wave stabilization ahead of the plate.
|
