Library Subscription: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-421-2

International Heat Transfer Conference 15
August, 10-15, 2014, Kyoto, Japan

Gas-Dynamic Temperature Stratification in a Compressible Low-Prandtle Gas Flow on a Permeable Wall

Get access (open in a dialog) DOI: 10.1615/IHTC15.fcv.009107
pages 3007-3016

Abstract

Heat transfer across the wall has been found, if compressible flows over a heat-conducting wall with subsonic speed on one side and trans- or supersonic speed on the other side. The heat flux is not equal to zero even when both parts of flow in the adiabatic channel from one tank. This effect is named gas-dynamic temperature stratification or energy-separation in a compressible flow. The equipment for investigating this effect is named the Leontiev tube. The Leontiev tube as the Ranque-Hilsch tube can be used for airconditioning, cooling food, cooling cutting tools, etc. The most cooling effect is found for the low-Prandtl gas mixtures (helium-xenon, hydrogen-xenon etc.). For these mixtures the recovery temperature on the adiabatic wall is less than that for air. Theoretically it is shown that heat transfer intensity depends on the recovery factor. When the recovery factor decreases, heat transfer increases and temperature stratification effect becomes more intensive. Even higher heat transfer and gas cooling we can found for a permeable heatconducting wall with blowing some part of subsonic speed flow into the supersonic flow. In this paper we present the numerical modeling results for temperature stratification in the Leontiev tube with permeable heat-conducting wall. The temperature distribution across the channel, heat flux from low-speed to highspeed flow, cooling effect, temperature efficiency, and adiabatic efficiency are analyzed for the heliumxenon mixture flow. It is shown that cooling efficiency increases in the Leontiev tube with the reduced permeability factor of heat-conducting wall from 10-12 to 5·10-12 [m].