Characteristics Of Fluid Flow And Flow Structures Of Non-Newtonian Fluid In A Wavy-walled Tube For Steady And Pulsatile Flow

With the development of the science and technology, the pressure imposed on the energy and environment becomes increasingly serious. The long-term strategy for the economic development is to reduce the consumption of the energy, which is more urgent comparing to explore new and utilize renewable energy.Mass and heat transfer devices with low energy consumption are wildly applied to the whole engineering field, such as biomedical, medical engineering. Mass and heat transfer process are often affected by system size, shape and efficiency in application. Many researchers devote themselves to the study of self-sustaining vibration and forced vibration of Newtonian fluids in the pipe of different shapes. The results reveal the characteristics of Newtonian fluid from the experimental and numerical aspects. A large number of studies have shown that the combination of self-sustaining vibration and forced vibration can lead to significantly enhance of mass and heat transfer.Preparation and applications of non-Newtonian fluids distribute widely in the chemical, food, petroleum, pharmaceutics and so on. Characteristics of fluid flow and flow structures of non-Newtonian fluid in the channel and tube are important references to the practical engineering. Based on pressure differences and flow visualization results, the characteristics of fluid flow and flow structures of non-Newtonian fluid in a wavy-walled tube for steady and pulsatile flow were described in this study.In chapter 1, it is a review of previous studies. These studies of Newtonian indicate that the experimental results agree with the results numerical simulation for steady and pulsatile flow in the channel and tube. However, little is known about non-Newtonian fluid, especially in the study about pulsatile flow.In chapter 2, the experimental apparatus and various measurement techniques which were applied to study are introduced, for example, measuring the whole pressure difference with U-shaped differential pressure gauge, visualizing the flow patterns by the aluminum dust method and recording the active trace of aluminum ion in wavy-walled tube by instantaneous photographs technology.Chapter 3 describes the experimental results. First, the basic characteristic of non-Newtonian fluids has been studied. It is found that temperature, storage time, shear rate and additives affect the characteristics of non-Newtonian fluid. Then, the operating parameters for test system are defined and the rotameter is calibrated. And then, flow visualization of non-Newtonian fluids in steady and pulsating flow was analyzed and the steady and unsteady flow structures were defined. Then, the effect of operating parameters on the mass transfer enhancement are discussed, such as Res, P and St. At last, it is found that three parameters had significant effect on the characteristic of mass and heat transfer. That is to say heat and mass transfer will be much better with larger Res, P and moderate St.Chapter 4 summarizes the experimental results. Operating parameters, the shape of wave-walled tube and the concentration of polymer solution have important impact on the characteristics of fluid flow and flow structures. The moderate concentration of polymer solution can reduce the frictional resistance. Compared with water, the effect of polymer solution on mass and heat transfer is significant enhanced at low Reynolds number.