Numerical aspects of simulating the flow-induced oscillations of a rectangular bluff body

The flow-induced oscillatory behavior of a rectangular body with a length-to-height ratio of L/H = 2 in incompressible, turbulent flow is numerically investigated at different Reynolds numbers based on the body length in a range between 2 x 10(4) and 12 x 10(4) at zero incidence. The body has one degree of freedom perpendicular to the mean-flow direction with a linear spring and linear damping. To compute the flow, a finite-volume based Navier-Stokes CFD-code is used, and a finite-difference-based algorithm is employed to solve the differential equation for the body vibration. The goals are the numerical simulation of an incident flow velocity at which resonance occurs, the exact determination of the physical mechanisms of the resonance, especially in the flowing medium, and a discussion of the numerical requirements to simulate the phenomenon. Key parameters of the overall model which exert influence on the quality of the simulation, e.g. turbulence modelling, time step and grid resolution, are examined. To achieve this aim, simulations with both steady and oscillating bodies are compared with experimental data and discrepancies are analyzed. Finally, an outlook on suggested future steps is given. (C) 2003 Elsevier Ltd. All rights reserved.