On Convective Heat Transfer In Rotating Pipe And Open End Effects

We can see the rotating curved pipes everywhere in the nature and engineering application. As a typical physical model and one of the basic problems in the field of fluid mechanics, the study of the fluid flow in curved pipes is through out the history of fluid mechanics. Scientists have taken interests in flow structure in curved pipes since the middle of the nineteenth century.Theoretic method and experimental method are the main methods in the study of natural science. The commonly used theoretic research methods are approximately theoretical analysis and numerical discretization techniques in the field of rotating curved pipes. Such as perturbation method is one of the most used theoretic methods in this field. By completely analyzing the references, we take advantage of the flow model of rotating curved pipes with multi parameters, which has widely application future, to study the entrance flow in. Using tension analysis, we present the continuity equation and momentum equations in a rotating helical right angle coordinate system and a rotating helical polar coordinate system. Then employing the numerical simulation (control volume method), we study the heat transfer and flow structure in the curved pipe which is rotating around any axis. The results show that heat transfer in curved pipe rotating around any axis is mainly effected by the four following parameters: Re (Reno number), Ro ( Rossby number), Pr(Prandtl number) , and a (the angle between rotating axis and pipe axis) . We discuss both the effects of different governing parameter a on the friction factor and flow structure and the effects of different Re and Ro numbers on Nu number. These provide the theoretic basis for the engineering application.What's more, we numerical study the entrance flow in rotating curved pipes of different cross section (η= 1, η>1η<1). We study the effects of all kinds of flow parameters and pipe parameters (Such as curvature, Dean number, Centrifugal force and Coriolis force) on axial main flow, the distance required for the flow to become fully developed, the develop of secondary flow and friction factor.By using the method of numerical simulation, we get large amount of data and graphics. After analysis we reach some conclusions. They are in good agreement with the results of other authors.