Heat Transfer of Non-Newtonian Drag Reducing Flow in Porous Media

Abstract

Forced convection heat transfer for non-Newtonian drag reduction (polyethylene oxide) with heat flux is experimentally studied in a pipe filled with plastic spheres porous media. Along the pipeline, installing pumping stations is expensive; reducing the drag inside the pipe is better. The effect of PEO concentration on the heat transfer properties in the pipe is studied. The experiments are used to demonstrate the effect of changing Reynolds number and PEO concentrations on Nusselt number of the water and polymer solutions for different diameter ratios (d/D) and different concentrations. In the experiments, the test section is a circular pipe filled with plastic spheres of different diameters (3.3, 5.5, and 6.8 mm) covered by an electric heater of nickel-chromium with a mica sheet to warm the test section with uniform heat flux (UHF). Thermocouples (k-Type) are used to measure the temperatures of water and different concentrations of polyethylene oxide solution (50, 100, 150, and 200 ppm). The results show that Nusselt number increases with increasing Reynolds number in water and polymer solutions (PEO). The local Nusselt number and Nusselt number increase with increasing diameter ratios (d/D) of porous media for water and polymer solutions (PEO). The thermal entrance length is independent on PEO concentration and the diameter ratios but depends only on Reynolds number. Correlations of the thermal entrance length as a function of Reynolds number and of Nusselt number as a functions of Reynolds number and diameter ratio (d/D) are obtained.

Keywords

• heat transfer
• drag reducing
• non-newtonian
• porous media
• polyethylene oxide