Wear analysis of tube-baffle vibration interaction in a tube bundle

Wear analysis has been carried out on aluminum tube in parallel triangular tube bundle with P/D ratio of 1.45 and the baffle plate placed at the mid-span of the bundle. The cross-flow velocity of water ranges from 0.18 m/s to 0.55 m/s. For each flow velocity, tests were performed on five different flow velocities and three-time spans (tube-baffle interaction) i.e., 30, 60, and 90 min. The experiments were designed in a unique way to study the relationship between cross flow velocity and tube baffle interaction time with wear produced on the tube surface. This is the first study of its kind in which wear analysis of a flexible tube has been done in the water tunnel to simulate the real environment of the heat exchanger tubes. The vibration response of the monitored tube was acquired using a tri-axial wireless accelerometer. A Scanning Electron Microscope (SEM) was used for the measurement of wear sizes. It was observed that the transverse amplitude rises significantly at higher velocities as compared to streamwise amplitude results in significant wear in the transverse direction. The wear sizes also tend to increase with the cross-flow velocity and become prominent at higher velocities. A similar trend has been observed for the wear area and wears volume. Also with the increase in the tube-baffle interaction span, the wear scar tends to be deeper and wider significantly at higher velocities.