A new heat eddy diffusivity equation for calculation of heat transfer to drag reducing turbulent pipe flows

✍ Scribed by H.K. Yoon; A.J. Ghajar

• Publisher: Elsevier Science
• Year: 1986
• Tongue: English
• Weight: 657 KB
• Volume: 13
• Category: Article
• ISSN: 0735-1933
• DOI: 10.1016/0735-1933(86)90008-4

✦ Synopsis

A new semi~empirlcal equation of heat eddy diffuslvlty in terms of friction drag reduction ratio and Weissenberg number is presented. The proposed equation was validated with heat transfer experimental results of Kwack [I] and our recent experimental results, both for aqueous solutions of polyacrylamlde (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 results of this study indicate that the proposed equation for eddy dlffusivlty 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 the Powell-Eyring fluid model and apparent viscosity measurements.