SOME ASPECTS OF HEAT-EXCHANGER TUBE DAMPING IN TWO-PHASE MIXTURES

Two-phase flow exists in many shell-and-tube heat exchangers. To avoid excessive flow-induced vibration, it is necessary to have information on damping. A simple experiment was undertaken to study the effect of several parameters such as void fraction, surface tension, tube frequency and confinement on damping in two-phase mixtures. The experiment consisted of a cantilevered tube immersed in a two-phase mixture generated by bubbling air through water. It is found that void fraction and flow regime are dominant parameters. Surface tension is also important. The results are presented in detail in the paper.