Abstract
Measurements of local void-fraction around tube in liquid-gas two-phase flow were carried out using a void probe technique. Horizontal tube bundle was set in a vertical rectangular channel with 90 X 90 mm^2, and the tube layout was in-line. Outer diameter of the tube was 15 mm, and the pitch to the diameter ratio was 1.5. Void fraction distributions were compared between 1^<st>, 4^<th> and 7^<th> rows at the center column. Furthermore, the differences of the void fractions were compared around between the center and wall side. Void fraction distributions at inlet of the tube bundle strongly affected on the void fraction distributions in the bundle. Void fraction deviation increased with gas-flow rate. The flow regime changed from bubbly to churn-turbulent flow with increasing of the gas-flow rate, and it increased bubbles' horizontal movement in the bundle. Therefore, the void fraction at 0° and 180° increased with gas-flow rate. As a result, the void fraction distributions around a tube became flat in churn-turbulent flow regime.
