Questions from Thermal Fluid Science

Q: A 9-ft-high room with a base area of

A 9-ft-high room with a base area of 12 ft × 12 ft is to be heated by electric resistance heaters placed on the ceiling, which is maintained at a uniform temperature of 90°F at all times. The floor of...

Q: A concentric annulus tube has inner and outer diameters of 25 mm

A concentric annulus tube has inner and outer diameters of 25 mm and 100 mm, respectively. Liquid water flows at a mass flow rate of 0.05 kg/s through the annulus with the inlet and outlet mean temper...

Q: A plate (0.5 m × 0.5 m

A plate (0.5 m × 0.5 m) is inclined at an angle of 30°. The top surface of the plate is well insulated. Estimate the rate of heat loss from the plate when the bottom surface is maintained at 60°C and...

Q: The gas tank of a car is filled with a nozzle that

The gas tank of a car is filled with a nozzle that discharges gasoline at a constant flow rate. Based on unit considerations of quantities, obtain a relation for the filling time in terms of the volum...

Q: A 4-L rigid tank contains 2 kg of saturated liquid

A 4-L rigid tank contains 2 kg of saturated liquid–vapor mixture of water at 50°C. The water is now slowly heated until it exists in a single phase. At the final state, wi...

Q: Consider a 4-m × 4-m × 4-

Consider a 4-m × 4-m × 4-m cubical furnace whose floor and ceiling are black and whose side surfaces are reradiating. The floor and the ceiling of the furnace are maintained at temperatures of 550 K a...

Q: Four power transistors, each dissipating 10 W, are mounted on

Four power transistors, each dissipating 10 W, are mounted on a thin vertical aluminum plate (k = 237 W/m⋅K) 22 cm × 22 cm in size. The heat generated by the transistors is to be dissipated by both su...

Q: A group of 25 power transistors, dissipating 1.5 W

A group of 25 power transistors, dissipating 1.5 W each, are to be cooled by attaching them to a black-anodized square aluminum plate and mounting the plate on the wall of a room at 30°C. T...

Q: Consider a circular grill whose diameter is 0.3 m.

Consider a circular grill whose diameter is 0.3 m. The bottom of the grill is covered with hot coal bricks at 950 K, while the wire mesh on top of the grill is covered with steaks initially at 5Â...

Q: Oil at 60°C flows at a velocity of 20 cm

Oil at 60°C flows at a velocity of 20 cm/s over a 5.0-m-long and 1.0-m-wide flat plate maintained at a constant temperature of 20°C. Determine the rate of heat transfer from the oil to the plate if th...