Tube bundles in cross-flow are subject to flow-induced vibrations which may cause severe damage in heat exchangers. Semi-empirical criteria for vibration stability can lead to an error of some 100 % in the calculation of the critical inflow velocity (Kassera 1997). This is why a numerical tool for simulation was developed. The numerics of the fully cartesian FSI code FIVSIC-3D for numerical simulation of flow-induced tube bundle vibration presented in a previous paper (Fischer and Strohmeier 1999b) were broadly extended. A number of differential schemes for the convective part of the Navier-Stokes Equations, a number of different solvers and a dynamic Large-Eddy model for turbulence were introduced. To check the code with literature, lift and drag coefficients as well as Strouhal numbers for Reynolds numbers from 2000 to 200000 were calculated for a rigid cylinder in cross flow with different mesh sizes and good agreement was found in comparison to experimental data. Special load function techniques for the coupling of fluid flow and tube dynamics were applied. CFL-based criteria were developed to garantuee numerical stability. A realistic heat exchanger model including inflow and outflow nozzles, two baffles with slip-stick tube support and 221 tubes was generated and transient RMS acceleration data for the tubes was compared to experiments conducted by the authors showing good agreement.
展开▼
