Investigation of whipping effect on high energy pipe based on fluid-structure interaction method

Abstract

A fluid-structure interaction numerical model has been established to investigate the whipping effect on high energy pipe in this study. The validation test has been performed by the comparison with the experimental results and it is found that the fluid-structure interaction model can well predict the displacement and the maximum restraint force of the piping system. Then, the dimensionless displacement of the cantilever pipe and U-bolt restraints, the maximum restraint force and the maximum strain energy are used to evaluate the effect of flow rate, pulsation frequency, overhang length, initial clearance and friction coefficient on the whipping effect. The results illustrate that the dimensionless root-mean-square displacement of the cantilever pipe and U-bolt restraints increase to 5.31 times and 9.41 times, respectively as the flow rate increases. The mode transition phenomenon occurs as the flow rate increases to over 180 kg/s and 284 kg/s, respectively. When the pulsation frequencies are close to the first natural frequency of the cantilever pipe, the resonance effect can enhance the whipping effect and enlarge the displacement of U-bolt restraints. The increase of overhang length, initial clearance and friction coefficient can also intensify the whipping effect.