Questions from Principles Of Heat Transfer

Q: Evaluate the Nusselt number for flow over a sphere for the following

Evaluate the Nusselt number for flow over a sphere for the following conditions: / /

Q: Air at 1000°C flows at an inlet velocity of 2

Air at 1000°C flows at an inlet velocity of 2 m/s between two parallel flat plates spaced 1 cm apart. Estimate the distance from the entrance to the point where the boundary layers meet.

Q: For liquid metals with Prandtl numbers much less than unity, the

For liquid metals with Prandtl numbers much less than unity, the hydrodynamic boundary layer is much thinner than the thermal boundary layer. As a result, one may assume that the velocity in the bound...

Q: A heat exchanger for heating liquid mercury is under development. The

A heat exchanger for heating liquid mercury is under development. The exchanger is visualized as a 15-cm-long and 0.3-m-wide flat plate. The plate is maintained at 70°C, and the mercury fl...

Q: The integral method also can be applied to turbulent-flow conditions

The integral method also can be applied to turbulent-flow conditions if experimental data for the wall shear stress are available. In one of the earliest attempts to analyze turbulent flow over a flat...

Q: A thin, flat plate is placed in an atmospheric pressure air

A thin, flat plate is placed in an atmospheric pressure air stream that flows parallel to it at a velocity of 5 m/s. The temperature at the surface of the plate is maintained uniformly at 200°C, and t...

Q: An array of 16 silicon chips arranged in 2 rows is insulated

An array of 16 silicon chips arranged in 2 rows is insulated at the bottom and cooled by air flowing in forced convection over the top. The array is located either with its long side or its short side...

Q: An electronic device is to be cooled by air flowing over aluminum

An electronic device is to be cooled by air flowing over aluminum fins attached to lower surface as shown. The device dissipates 5 W, and the thermal contact resistance between the lower surface of th...

Q: The six identical aluminum fins shown in the sketch are attached to

The six identical aluminum fins shown in the sketch are attached to an electronic device for cooling. Cooling air is available at a velocity of 5 m/s from a fan at 20°C. If the average temp...

Q: A 2.5-cm-diameter, 15-cm

A 2.5-cm-diameter, 15-cm-long transit rod (k = 0.97 on the end of a 2.5-cm-diameter wood rod at a uniform temperature of 100°C is suddenly placed into a 16°C, 30 m/s air stream...