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The spectral, hemispherical absorptivity of an opaque surface is as shown. What is the solar absorptivity, aS?
The objective of an experiment performed by our students is to determine the effect of pin fins on the thermal resistance between a flat plate and an airstream
The neighborhood cat likes to sleep on the roof of our shed in the backyard. The roofing surface is weathered galvanized sheet metal (e = 0.65, aS = 0.8)
The heat transfer coefficients for the flow of 26.6°C air over a 1.25 cm diameter sphere are measured by observing the temperature-time history of a copper ball
The handle of a ladle used for pouring molten lead is 30 cm long. Originally the handle was made of 1.9 A 1.25 cm mild steel bar stock.
Simplify this equation by eliminating terms equal to zero for the case of steady -state heat flow without sources or sinks around a right-angle corner
The exposed surface of a power amplifier for an earth satellite receiver of area 130 mm by 130 mm has a diffuse, gray, opaque coating with an emissivity of 0.5.
The directional absorptivity of a gray surface varies with as follows.
The density and specific heat of a plastic material are known (p = 950 kg/m3, cp = 1100 J/kg · K), but its thermal conductivity is unknown.
The cross section of a long circular tube, which is divided into two semi cylindrical ducts by a thin wall, is shown below
The density and specific heat of a particular material are known (p = 1200 kg/m3 · c p = 1250 J/kg · K), but its thermal conductivity is unknown
The core of a high-temperature, gas-cooled nuclear reactor has coolant tubes of 20-mm diameter and 780-mm length
The convection coefficient for flow over a solid sphere may be determined by submerging the sphere which is initial1y at 25°C, into the flow
The bottom of a copper pan, 150 mm in diameter, is maintained at 115°C by the heating element of an electric range.
Saturated steam at 4 bars absolute pressure with a mean velocity of 3 m/s flows through a horizontal pipe whose inner and outer diameters are 55 and 65 mm
One of the strengths of numerical methods is their ability to handle complex boundary conditions. In the sketch, the boundary condition changes
One hundred electrical components each dissipating 25 W, are attached to one surface of a square (0.2 m x 0.2 m) copper plate, and all the dissipated energy
On an overcast day the directional distribution of the solar radiation incident on the earth's surface may be approximated by an expression of the form
In the production of sheet metals or plastics, it is customary to cool the material before it leaves the production process for storage or shipment
In thermo mechanical data storage, a processing head, consisting of M heated cantilevers, is used to write data onto an underlying polymer storage medium.
In the spring, concrete surfaces such as sidewalks and driveways are sometimes very wet in the morning, even when it has not rained during the night.
It is common practice to recover waste heat from an oil-or gas-fired furnace by using the exhaust gases to preheat the combustion air.
It is proposed to air-cool the cylinders of a combustion chamber by joining an aluminum casing with annular fins (k = 240 W/m · K) to the cylinder wall
It is proposed that the exhaust gas from a diesel powered electric generation plant be used to generate steam in a shell-and-tube heat exchanger with one shell
In the first stage of a paper drying process, a cylinder of diameter 0.15 m is covered by moisture-soaked paper.