Flow structure and turbulent transport of a supercritical pressure fluid in a vertical heated tube under the conditions of mixed convection. Experimental data

• Published in: International journal of heat and mass transfer 1993-09, Vol.36 (13), p.3383-3392
• Main Authors: Kurganov, V.A., Kaptilnyi, A.G.
• Format: Article
• Language: English
• ISSN: 0017-9310; 1879-2189
• DOI: 10.1016/0017-9310(93)90020-7

Experimental data on the velocity and temperature fields of a heated turbulent supercritical-pressure carbon dioxide flow in a 22.7 mm dia. vertical tube under the conditions of mixed convection are obtained. A comparative analysis of the results of measurements for buoyancy assisted and opposed upward and downward flows has allowed a conclusion that a relative deterioration in heat transfer in the case of an upward flow with the development of the inlet wall temperature peaks is attributable to the rearrangement of velocity fields and shear stresses in the course of which a fluid layer with reduced turbulence generation appears. Based on the results of measurements of velocity and temperature fields, heat transfer and hydraulic drag, the profiles of shear stresses and heat fluxes as well as the eddy diffusivities and turbulent Prandtl numbers have been calculated which are compared with some turbulent transfer models applied for calculating heat transfer in the supercritical region.