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ISSN Online: 2377-424X

ISBN Print: 0-89116-559-2

International Heat Transfer Conference 8
August, 17-22, 1986, San Francisco, USA

A NEW HEAT EDDY DIFFUSIVITY EQUATION FOR CALCULATION OF HEAT TRANSFER TO DRAG REDUCING TURBULENT PIPE FLOWS

Get access (open in a dialog) DOI: 10.1615/IHTC8.1880
pages 937-942

Resumo

A new semi-empirical equation of heat eddy diffusivity in terms of friction drag reduction ratio and Weissenberg number is presented. The proposed equation was validated with heat transfer experimental results of Kwack and our recent experimental results, both for aqueous solutions of polyacrylamide (Separan AP-273) for concentrations ranging from 10 to 1000 ppm in turbulent flow through pipes under constant wall heat flux condition. The predictions of heat transfer coefficients with the use of the proposed equation are in good agreement with both sets of independent experimental results. The predictions for all concentrations result in a maximum of 30 percent deviation from the measurements. The results of this study indicate that the proposed equation for eddy diffusivity of heat has predictive capability provided experimental measurements of pressure drop and the fluid time scale are available. The fluid time scale for these predictions was estimated using Powell-Eyring fluid model and apparent viscosity measurements.