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A square (10 mm x 10 mm) silicon chip is insulated on one side and cooled on the opposite side by atmospheric air in parallel flow at U8 = 20 m/s
A small radiant source A1 emits diffusely with an intensity I1 = 1.2 x 105 W/m2 · sr. The radiation detector A2 is aligned normal to the source at a distance
A small dam, which may be idealized by a large slab 1.2 m thick, is to be completely poured in a short period of time. The hydration of the concrete results
A small disk of diameter D1 = 50 mm and emissivity e1 = 0.6 is maintained at a temperature of T1 = 900 K. The disk is covered with a hemispherical radiation
A sphere made of aluminum alloy 2024 with a diameter of 20 mm and a uniform temperature of 500°C is suddenly immersed in a saturated water bath
If the sides and bottom of the container are well insulated from the surroundings and heat is uniformly dissipated in each circuit
A silicon chip (k = 150 W/m · K, p = 2300 kg/m3, c p = 700 J/kg · K), 10 mm on a side and 1 mm thick, is connected to a substrate by solder balls
A simplified representation for cooling in very large-scale integration (VLSI) of microelectronics is shown in the sketch
A silicon chip of thickness L = 2.5 mm and thermal conductivity ks = 135 W/m · K is cooled by boiling a saturated fluorocarbon liquid (Tsat = 57°C)
A shell-and-tube exchanger (two shells, four tube passes) is used to heat 10,000 kg/h of pressurized water from 35 to 120°C with 5000 kg/h pressurized
A single-pass, cross-flow heat exchanger with both fluids unmixed is being used to heat water (mc = 2 kg/s. cp = 4200 J/kg · K) from 20°C to 100°C
A single-pass, cross-flow heat exchanger uses hot exhaust gases (mixed) to heat water (unmixed) from 30 to 80°C at a rate of 3 kg/s.
A procedure for measuring the thermal conductivity of solids at elevated temperatures involves placement of a sample at the bottom of a large furnace.
A probe of overall length L = 200 mm and diameter D = 12.5 mm is inserted through a duct wall such that a portion of its length, referred to as the immersion
A radiant heater, which is used for surface treatment processes, consists of a long cylindrical heating element of diameter D1 = 0.005 m and emissivity e1 = 0.8
A re-cooperator is a heat exchanger that heats air used in a combustion process by extracting energy from the products of combustion.
A radiative heater consists of a bank of ceramic tubes with internal heating elements. The tubes are of diameter D = 20 mm and are separated by a distance
A procedure for determining the thermal conductivity of a solid material involves embedding a thermocouple in a thick slab of the solid and measuring
A one-dimensional slab of thickness 2L is initially at a uniform temperature Ti. Suddenly, electric current is passed through the slab
A passive technique for cooling heat-dissipating integrated circuits involves submerging the ICs in a low boiling point dielectric fluid.
A plane wall 15 cm thick has a thermal conductivity given by the relation k = 2.0 + 0.0005 T W/(m K) where T is in degrees Kelvin
A plate of thickness 2L = 25 mm at a temperature of 600°C is removed from a hot pressing operation and must be cooled rapidly in order to achieve the required
A major problem in packaging very large-scale integrated (VLSI) circuits concerns cooling of the circuit elements
A metal rod of length 2L, diameter D, and thermal conductivity k is inserted into a perfectly insulating wall, exposing one-half of its length to an air stream
Assume that we've taken a radiograph of a small circular plastic object from which we have made the following relative exposure measurements