Q: A very thin silicon chip is bonded to a 6-mm
A very thin silicon chip is bonded to a 6-mm thick aluminum substrate by a 0.02-mm thick epoxy glue. Both surfaces of this chip-aluminum system are cooled by air at 258C, where the convective heat tra...
See AnswerQ: A thin, flat plate integrated circuit is cooled on its upper
A thin, flat plate integrated circuit is cooled on its upper surface by a dielectric liquid. The heat dissipation rate from this chip is 20,000 W/m2 and with the coolant flow at a free-stream temperat...
See AnswerQ: In a large chemical factory, hot gases at 2273 K are
In a large chemical factory, hot gases at 2273 K are cooled by a liquid at 373 K with gas-side and liquid- side convection heat transfer coefficients of 50 and 1000 W/m2. K, respectively. The wall tha...
See AnswerQ: Consider a flat plate or a plane wall with a thickness L
Consider a flat plate or a plane wall with a thickness L and a long cylinder of radius ro. Both of these are made of materials such that they can be treated as lumped capacitances (Bi < 0.1) . Show...
See AnswerQ: A spherical shell satellite (3-m-OD, 1
A spherical shell satellite (3-m-OD, 1.25-cm-thick stainless steel walls) re-enters the atmosphere from outer space. If its original temperature is 38°C, the effective average temperature of the atmos...
See AnswerQ: In the heat treating process in a sheet-metal manufacturing plant
In the heat treating process in a sheet-metal manufacturing plant, brass plates are annealed by first heating them in an industrial furnace oven the inside of which is maintained at a constant uniform...
See AnswerQ: A thermocouple (0.8-mm-diameter wire)
A thermocouple (0.8-mm-diameter wire) used to measure the temperature of the quiescent gas in a furnace gives a reading of 165°C. It is known, how- ever, that the rate of radiant heat flow...
See AnswerQ: A spherical stainless steel vessel at 93°C contains 45 kg
A spherical stainless steel vessel at 93°C contains 45 kg of water initially at the same temperature. If the entire system is suddenly immersed in ice water, determine (a) the time required for the wa...
See AnswerQ: A copper wire, 0.8-mm OD, 5
A copper wire, 0.8-mm OD, 5 cm long, is placed in an air stream whose temperature rises at a rate given by where t is the time in seconds. If the initial temperature of the wire is 10°C, d...
See AnswerQ: A thin-wall cylindrical vessel (1 m in diameter)
A thin-wall cylindrical vessel (1 m in diameter) is filled to a depth of 1.2 m with water at an initial temperature of 15°C. The water is well stirred by a mechanical agitator. Estimate the...
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