Two-Phase Cross Flow Damping in Tube Arrays

摘要

To avoid excessive flow-induced vibration at the U bend spans of steam generators it is necessary to have information on two-phase flow damping. This paper reviews the data we obtained in different tube arrays subjected either to air/water or to steam/water flows, at high void fraction. At first, experimental difficulties in obtaining reliable damping measurements in flexible tube arrays are emphasized. However, the present data are still certainly tainted with experimental errors. It appears clearly that void fraction and nature of the two-phase mixture are important parameters for controlling two-phase flow damping in tube arrays. Namely dissipation is found to be significantly less in steam/water than in air/water, at least in the high void fraction range.