Thermal behavior of simulated chips during power-off transient period

Experiments are conducted to study the heat transfer characteristics from an array of 4/spl times/1 flush mounted simulated electronic chips using water as the working fluid in a vertical up-flow rectangular channel. The data covers a range of laminar flow data with Reynolds number based on heat source length ranging from 1050 to 2625 for an inlet water temperature of about 23/spl deg/C. The applied uniform heat fluxes to the chips are 2, 4, 6 and 8 W/cm/sup 2/. Steady state results are obtained to ensure that the test rig is in good working condition. Experiments are then extended to study the transient heat transfer regime for 75 s after the heater power is cut-off, keeping the coolant pump power on. The effects of heat flux, coolant flow rates and geometric parameters such as chip numbers are investigated. Finally, the correlation equations are presented for individual chips as well as for overall data in the transient regime.