A CFD Based Investigation For Evaluation of Steady and Unsteady Hydrodynamic Performance of 3D Tailfin as an Isolated Surface a.pdf

1、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 whic

2、h 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 ve

3、hicle 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 flu

4、id 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 intereste

5、d 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

6、 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 for

7、ces 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 a

8、re 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 o

9、n 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 isol

10、ated 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 isolate

11、d 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 exp

12、erimental 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 sup

13、ported 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 experime

14、ntal 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 metho

15、d 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