Effects of rolling motion on thermal-hydraulic characteristics of boiling flow in rectangular narrow channel

Experimental investigations on thermal-hydraulic characteristics of boiling flow in a rectangular narrow channel under rolling motion conditions are carried out. This experiment is designed to elucidate the phenomena of boiling flow under rolling motion and to give the corresponding rational explanations. The results show that the amplitudes of fluctuations of pressure drop, flow rate, fluid and wall temperatures, and boiling heat transfer coefficient increase with the increasing of rolling amplitude and rolling period. The phase difference of flow rate fluctuation and pressure drop fluctuation is 1/4 period, and the saturated water temperature fluctuations of the test section delay 2-3 s behind the pressure drop fluctuations. The time average boiling heat transfer coefficients of the rectangular narrow channel under rolling motion are equal to those under static conditions. The amplitude of boiling heat transfer coefficient of test section increases with increasing heat flux and flow rate, while decreases with increasing system pressure. (C) 2014 Elsevier Ltd. All rights reserved.