DRAG REDUCTION BY CULTURE SOLUTIONS OF DRY MALTED RICE

Turbulent drag reduction by culture solutions of dry malted rice was investigated in a 2.00mm-inner- diameter pipe flow of length 50 diameters at Reynolds numbers from 500 to 8000. The drag reducing abilities of the solutions were tested by comparing drag reduction effectiveness at different concentrations and culture times in water. Comparisons between polysaccharide biopolymer solutions and culture solutions of dry malted rice revealed that the test solutions exhibited Type B drag reduction, which were roughly parallel to, but displaced upwards from, the Newtonian Prandtl-Karman law. The maximum drag reduction ration was about 30% at a Reynolds number of 8,000. It is shown also that the onset point of drag reduction phenomena was Re root f=200