NUMERICAL SIMULATION OF THE HYDRODYNAMIC PERFORMANCE OF AN UNSYMMETRICAL FLAPPING CAUDAL FIN  

作　　者：ZHANG Xi SU Yu-min WANG Zhao-li 

机构地区：[1]State Key Laboratory of Autonomous Underwater Vehicle, Harbin Engineering University, Harbin 150001, China,

出　　处：《Journal of Hydrodynamics》2012年第3期354-362,共9页水动力学研究与进展B辑（英文版）

基　　金：supported by the National Nature Science Foundation of China(Grant No.50879014);the Doctoral Program of Higher Education of China(Grant No.200802170010)

摘　　要：A comprehensive numerical simulation of the hydrodynamic performance of a caudal fin with unsymmetric flapping motion is carried out. The unsymmetrical motion is induced by adding a pitch bias or a heave bias. A numerical simulation program based on the unsteady panel method is developed to simulate the hydrodynamics of an unsymmetrical flapping caudal fin. A CFD code based on Navier-Stokes equations is used to analyze the flow field. Computational results of both the panel method and the CFD method indicate that the hydrodynamics are greatly affected by the pitch bias and the heave bias. The mean lateral force coefficient is not zero as in contrast with the symmetrical flapping motion. By increasing the pitch bias angle, the mean thrust force coefficient is reduced rapidly. By adding a heave bias, the hydrodynamic coefficients are separated as two parts： in one part, the amplitude is the heave amplitude plus the bias and in the other part, it is the heave amplitude minus the bias. Analysis of the flow field shows that the vortex distribution is not symmetrical, which generates the non-zero mean lateral force coefficient.A comprehensive numerical simulation of the hydrodynamic performance of a caudal fin with unsymmetric flapping motion is carried out. The unsymmetrical motion is induced by adding a pitch bias or a heave bias. A numerical simulation program based on the unsteady panel method is developed to simulate the hydrodynamics of an unsymmetrical flapping caudal fin. A CFD code based on Navier-Stokes equations is used to analyze the flow field. Computational results of both the panel method and the CFD method indicate that the hydrodynamics are greatly affected by the pitch bias and the heave bias. The mean lateral force coefficient is not zero as in contrast with the symmetrical flapping motion. By increasing the pitch bias angle, the mean thrust force coefficient is reduced rapidly. By adding a heave bias, the hydrodynamic coefficients are separated as two parts： in one part, the amplitude is the heave amplitude plus the bias and in the other part, it is the heave amplitude minus the bias. Analysis of the flow field shows that the vortex distribution is not symmetrical, which generates the non-zero mean lateral force coefficient.

关 键 词：flapping caudal fin caudal fin shape numerical simulations hydrodynamic experiments hydrodynamic performance 

分 类 号：U661.313[交通运输工程—船舶及航道工程] O35[交通运输工程—船舶与海洋工程]