Numerical Analysis of Fluidelastic Instability in a Normal Triangular Tube Array

Abstract

Investigation of steady flow through a normal triangular tube bundle is carried out numerically using a 2D Reynolds Averaged Navier-Stokes solver. Pitch to diameter ratios of 1.25 and 1.32 are simulated with a single tube displaced and the resulting force coefficients measured. Comparison of pressure coefficient with experimental data indicates simulations provide a reliable indication of Reynolds number dependence. These fluid force coefficients are then used as input into the quasi-unsteady model in order to predict the critical velocity of damping controlled fluidelastic instability for a single degree of freedom tube within an array. The predicted critical velocities are in the range of empirical data from the literature. The predicted critical velocities for the pitch ratio of 1.25 are within 30% of the experimental values previously reported.