Investigation on Stability of an Elastically Mounted Circular Tube Under Cross-Flow in Inline Square Arrangement

The results of an experimental investigation of flow perturbations coupled with tube vibrations along the interstitial flow path are presented. An inline square tube array at different operating conditions with a pitch ratio of 1.85 is calculated. Interstitial flow perturbations measurements all along the flow path were recorded using a hot-wire probe while monitoring the tube vibration in the streamwise and cross-flow directions. The outcomes of tube vibration amplitude, mean gap velocity frequency and measurement position of the hot-wire probe on the amplitude of the flow perturbation and comparative phase were examined. It is observed that the perturbations of the fluid flow are primarily evident at the position of separation of the fluid flow from the test tube and decay swiftly with space from this position. It shows that the time delay between tube vibration and perturbation of the flow is associated with the separation of the flow and enhanced vortices were a result of the tube vibration.