Questions from Principles Of Heat Transfer

Q: Compare the rate of heat loss from a human body with the

Compare the rate of heat loss from a human body with the typical energy intake from consumption of food (4.325 MJ/day). Model the body as a vertical cylinder 30 cm in diameter and 1.8 m high in still...

Q: An electric room heater has been designed in the shape of a

An electric room heater has been designed in the shape of a vertical cylinder 2 m tall and 30 cm in diameter. For safety, the heater surface cannot exceed 35°C. If the room air is at 20°C, find the po...

Q: A long, heated, cylindrical steel rod is removed from a

A long, heated, cylindrical steel rod is removed from a heat treatment furnace and has to be cooled to complete the process. If the surface temperature of the rod is at 150°C and the cooling fluid tem...

Q: Consider a design for a nuclear reactor using natural- convection heating

Consider a design for a nuclear reactor using natural- convection heating of liquid bismuth as shown. The reactor is to be constructed of parallel vertical plates 1.8 m tall and 1.2 m wide in which he...

Q: A mercury bath at 60°C is to be heated by

A mercury bath at 60°C is to be heated by immersing cylindrical electric heating rods, each 20 cm tall and 2 cm in diameter. Calculate the maximum electric power rating of a typical rod if its maximum...

Q: An electric heating blanket is subjected to an acceptance test. It

An electric heating blanket is subjected to an acceptance test. It is to dissipate 400 W on the high set- ting when hanging in air at 20°C. (a) If the blanket is 1.3 m wide, what is the length requir...

Q: An aluminum sheet 0.4 m tall, 1 m long

An aluminum sheet 0.4 m tall, 1 m long, and 0.002 m thick is to be cooled from an initial temperature of 150°C to 50°C by immersing it suddenly in water at 20°C. The...

Q: A 0.1-cm-thick square, flat copper

A 0.1-cm-thick square, flat copper plate, 2.5 m * 2.5 m, is to be cooled in a vertical position. The initial temperature of the plate is 90°C with the ambient fluid at 30°C. The fluid medium is either...

Q: A composite refrigerator wall is composed of 5 cm of corkboard sandwiched

A composite refrigerator wall is composed of 5 cm of corkboard sandwiched between a 1.2-cm-thick layer of oak and a 0.8-mm-thick layer of aluminum lining on the inner surface. The average convection...

Q: A laboratory apparatus is used to maintain a horizontal slab of ice

A laboratory apparatus is used to maintain a horizontal slab of ice at –2.2°C so that specimens can be prepared on the surface of the ice and kept close to 0°C. If the ice is 10 cm 3 3.8 cm and the la...