Q: A 2.5-cm sphere is to be maintained at
A 2.5-cm sphere is to be maintained at 50°C in either an airstream or a water stream, both at 20°C and 2 m/s velocity. Compare the rate of heat transfer and the drag on the sphere for the two fluids....
See AnswerQ: Determine the effect of forced convection on heat transfer from a 100
Determine the effect of forced convection on heat transfer from a 100-W, spherical glass bulb, incandescent lamp. What would be the glass temperature for air velocities of 0.5, 1, 2, and 4 m/s?
See AnswerQ: An experiment was conducted in which the heat transfer from a sphere
An experiment was conducted in which the heat transfer from a sphere in sodium was measured. The sphere, 0.5 in. in diameter, was pulled through a large sodium bath at a given velocity while an electr...
See AnswerQ: A copper sphere initially at a uniform temperature of 132°C
A copper sphere initially at a uniform temperature of 132°C is suddenly released at the bottom of a large bath of bismuth at 500°C. The sphere diameter is 1 cm, and it rises thr...
See AnswerQ: A spherical water droplet of 1.5-mm diameter is
A spherical water droplet of 1.5-mm diameter is freely falling in atmospheric air. Calculate the average convection heat transfer coefficient when the droplet has reached its terminal velocity. Assume...
See AnswerQ: In a lead-shot tower, spherical 0.95-
In a lead-shot tower, spherical 0.95-cm-diameter BB shots are formed by drops of molten lead, which solidify as they descend in cooler air. At the terminal velocity, i.e., when the drag equals the gra...
See AnswerQ: A copper sphere 2.5 cm in diameter is suspended by
A copper sphere 2.5 cm in diameter is suspended by a fine wire in the center of an experimental hollow, cylindrical furnace whose inside wall is maintained uniformly at 430°C. Dry air at a temperature...
See AnswerQ: A section of a composite wall with the dimensions shown below has
A section of a composite wall with the dimensions shown below has uniform temperatures of 200°C and 50°C over the left and right surfaces, respectively. If the thermal conductivi...
See AnswerQ: Steam at 100 kPa and 100°C is flowing across a
Steam at 100 kPa and 100°C is flowing across a 5-cm- OD tube at a velocity of 6 m/s. Estimate the Nusselt number, the heat transfer coefficient, and the rate of heat transfer per meter length of pipe...
See AnswerQ: A method for measuring the convection heat transfer from spheres has been
A method for measuring the convection heat transfer from spheres has been proposed. A 20-mm-diameter copper sphere with an embedded electrical heater is to be suspended in a wind tunnel. A thermocoupl...
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