Two- and three-dimensional CFD-simulation of flow-induced vibration excitation in tube bundles

Abstract

Two- and three-dimensional simulation models for the computation of flow-induced vibration of tube bundles subjected to single-phase cross-flow are applied for a full flexible tube row and a tube bundle. The flow-induced vibration is simulated with the CFD (Computational Fluid Dynamics) program STAR-CD in combination with a coupled solver for the differential equations of parallel vibrating tubes for two- and three-dimensional calculations. Additionally a coupled FEM (Finite Element Method) program is used for the three-dimensional simulation of different tube support conditions. The CFD program solves the Navier–Stokes equations with different kε-models or an implemented kω-model for the unsteady turbulent viscous and incompressible flow field. The object of this project is to find a model, which describes the fluidelastic vibration excitation and enables an accurate computation of critical velocities in tube bundles comparable to those determined with the new design recommendation by K. Schröder and H. Gelbe, New design recommendations for fluidelastic instability in heat exchanger tube bundles, ASME AD-Vol. 53–2, Fluid-Structure Interaction, Aeroelasticity, Flow-Induced Vibration and Noise, 1997, Volume II, pp. 211-219 (s. a. Journal of Fluids and Structures, 13 (1999), to be published). Then it will be possible to investigate independently the influence of the structure data and the fluid properties on the onset of instability. The presented model is validated with experimental data and compared with existing models in the literature. Different grid discretizations of the flow field and turbulence models were tested for rigid and flexible tubes and the simulation results for the fluid forces, the pressure distributions and the onset of instability are compared with experimental data for a tube, a tube row and a tube bundle subjected to cross flow.