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原文传递 A CFD Based Investigation For Evaluation of Steady and Unsteady Hydrodynamic Performance of 3D Tailfin as an Isolated Surface and When Attached as an Appendage with UUV Body

论文题名：	A CFD Based Investigation For Evaluation of Steady and Unsteady Hydrodynamic Performance of 3D Tailfin as an Isolated Surface and When Attached as an Appendage with UUV Body
关键词：	UUV;3D Tailfin;CFD;RANSE;Hydrodynamic Performance
摘要：	The development of Autonomous unmanned underwater vehicles (UUVs) has progressed quite significantly in the past decade due in large part to the increasing interest in unmanned underwater surveillance and monitoring which has led the researchers to turn there attention on the evaluation of hydrodynamic performance of fin and control surfaces associated with such underwater vehicles. The study of fin and control surfaces of underwater vehicle whether stationary or moving in a fluid is an interesting and challenging research subject in the field of underwater locomotion and propulsion for underwater vehicle. Typically the effect of Fin oscillation on fluid flow around such a body is highly unsteady, generating vortices and requiring detailed analysis of fluid-structure interactions. An understanding of the complexities of such flows is of interest to engineers interested in developing vehicles capable of emulating the high dynamic performance of propulsion and maneuvering. A useful tool for gaining an understanding of the performance of a UUV is a dynamic simulation of the equations of motion of the vehicle. To perform these simulations the hydrodynamic coefficients of the vehicle must first be provided, these coefficients are specific to the vehicle and provide the description of the hydrodynamic forces and moments acting on the vehicle in its underwater environment. A part of the contribution to these hydrodynamic coefficients is provided by the lifting surfaces such as propeller, stern plane, bow plane ere which are attached as an appendage to the UUV body. As matter of fact out of five longitudinal and three lateral hydrodynamic coefficients few largely depends upon the tailfin geometry as well as the forces and moments acting on the tailfin. In the present study, a computational fluid dynamic (CFD) RANSE simulation of a 3D Tailfin body has been developed to investigate the hydrodynamic performance (Lift, Drag and Moment Coefficient) as an isolated surface and when attached as an appendage to the UUV body in steady and unsteady flow conditions. The present work is accomplished in three different parts:1. In the first part Hydrodynamic performance of an isolated 3D Tailfin body in interaction with the viscous flow is evaluated separately with structured and unstructured grid in steady state flow conditions at various values of attack angles, results are supported using the experimental data.2. The second part addresses the evaluation of unsteady state hydrodynamic performance of an isolated 3D Tailfm at two different Oscillation frequencies T = 4.5 seconds and T=5.928 Seconds, results are supported using the experimental data.3.The third part briefly covers the steady and unsteady state analyses of 3D Tailfin used as an appendage with the UUV body of 10 meters, here the results are compared with the experimental data of isolated 3D Tailfin along with the traditional theoretical Lifting-line theory or LanchesterPrandtl wing theory in order to support the work.In this simulation, an implicit pressure-based finite volume method is used for time dependent and independent accurate computation of incompressible flow using first and second order accurate convective flux discretisation schemes. A parametric analysis of the factors that affect the hydrodynamic performance of the 3D Tailfin body is presented, along with the comparison of results with the experimental data and supporting theoretical material.
作者：	Zulfiqar Nazir
专业：	Naval Architecture Engineering
导师：	Su Yumin
授予学位：	硕士
授予学位单位：	哈尔滨工程大学
学位年度：	2008
正文语种：	中文