Drag Reduction Of Non-Newtonian Fluid In A Wavy-walled Tube For Steady Flow

The investigation of Non-Newtonian fluid in the industry has improved greatly with the development of science and technique, especially in the field of biology. The additive polymers and surfactants have extensive use in disposing water, petroleum industry and biochemical plant aspect. Lots of researches focus on the flow characteristic of non-Newtonian fluid in 2-D and 3-D pipes, but relatively a little in a wavy-walled tube which is apt to bring the separation flow and enhance the mass and heat transfer. The paper mainly investigates the flow characteristic of non-Newtonian fluid in a wavy-walled tube, especially the drag reduction. At the same time, the proper numerical simulation and flow visualization are compared with experimental result. The details follow:In chapter 1, the studies that the flow characteristic of non-Newtonian fluid in pipes have been reviewed. It is shown the experimental results in channel are coincident with the numerical simulation. In 50's, Toms found that dissolving a small amount of polymers in water can drastically reduce the pressure drop in the straight pipe and improve heat transfer, but the transitional point delays compared with water. The researches of non-Newtonian fluid in wavy-walled tube which enhances the mass and heat transfer haven't been under way.In chapter 2, the experimental facility and measurement techniques used in the study are introduced. Two kinds of wavy-walled tubes are selected in test section. The basic physical characteristics such as shear viscosity and shear stress are educed by a revolving viscosimeter. The flow characteristic of non-Newtonian fluid in wavy-walled tube is studied by a circulating system and the flow patterns are visualized by the aluminum dust method.In chapter 3, the experimental results are discussed. First of all, rheology of PAM is analyzed. Next, the f-Re curve of PAM polymer solution in wavy-walled tube is attained and the drag reduction phenomenon is observed. The best drag reduction effect is received via various concentration PAM while the transitional flow moves up as the drag reduction compared with the Newtonian fluid. The velocity and pressure distributions of PAM are acquired by using FLUENT6.0 and ihef-Re curve is similar to experimental result.Chapter 4,5 indicates the possible extensions of the present work.