THE CHARACTERISTICS OF HEAT TRANSFER IN A NARROW RECTANGULAR CHANNEL UNDER ROLLING MOTION

摘要

An experimental investigation of forced convection heat transfer was conducted in a narrow rectangular channel under rolling motion. Experimental results show that rolling motion induces the flow fluctuate periodically, and the amplitude of fluctuation decreases sharply with increasing Reynolds number. The periodic oscillation of flow rate causes the temperature of outlet water and outer surface of the heating wall fluctuate periodically. The amplitudes of fluctuation for both outlet water temperature and outer surface temperature of heating wall increase with increasing rolling amplitude and rolling frequency in the turbulent region. The heat transfer coefficient under rolling motion was almost the same as that in steady condition in turbulence region. The reason is that the flow rate fluctuates with small amplitude at relatively high flow rate, thus the effect of rolling motion on the heat transfer is negligible in this experiment.