Numerical simulation of FIV of PTC-cylinder with nonlinear springs at high Reynolds number

Abstract

ObjectiveThis article studies the characteristics of the flow-induced vibration (FIV) of a cylinder with passive turbulence control and nonlinear springs in a wide range of Reynolds numbers in order to use the FIV of the PTC-cylinder to improve the efficiency of power generators.MethodsThe FIV of a PTC-cylinder supported by linear and nonlinear springs is studied by solving the 2-D URANS equations in combination with the Spalart-Allmaras turbulence model with dynamic mesh and user-defined-function (UDF) in FLUENT. The numerical simulation results are compared with the experimental results.ResultsCompared with linear springs, the amplitude of a cylinder with piecewise-linear springs is enhanced significantly, and the vortex mode becomes more complicated. When the spring stiffness of the first segment is greater than that of the second segment, the amplitude of the cylinder becomes larger, the oscillation frequency becomes smaller and the vortex mode of the cylinder becomes more complicated as the piecewise point of the piecewise-linear function becomes smaller.ConclusionsThe FIV of a PTC-cylinder with nonlinear springs is different from that with linear springs. The fluid-structure interaction is enhanced effectively with the reasonable selection of the piecewise point, providing theoretical and technical support for improving the efficiency of hydrokinetic energy conversion devices.

Keywords

• ptc-cylinder
• nonlinear springs
• flow-induced vibration
• high reynolds numbers