Questions from Thermal Fluid Science

Q: Repeat Prob. 20–82 assuming the plate to be positioned

Repeat Prob. 20–82 assuming the plate to be positioned horizontally with (a) transistors facing up and (b) transistors facing down. Data from Prob. 20-82: A group of 25 power transi...

Q: Consider a 10-ft × 10-ft × 10-

Consider a 10-ft × 10-ft × 10-ft cubical furnace whose top and side surfaces closely approximate black surfaces and whose base surface has an emissivity ε = 0.4. The base, top, and side surfaces of th...

Q: Consider an L × L horizontal plate that is placed in quiescent

Consider an L × L horizontal plate that is placed in quiescent air with the hot surface facing up. If the film temperature is 20°C and the average Nusselt number in natural con...

Q: The passenger compartment of a minivan traveling at 70 mph can be

The passenger compartment of a minivan traveling at 70 mph can be modeled as a 3.2-ft-high, 6 ft-wide, and 12-ft-long rectangular box whose walls have an insulating value of R-3 (i.e., a wall thicknes...

Q: Reconsider Prob. 21–103E. Using appropriate software, investigate

Reconsider Prob. 21–103E. Using appropriate software, investigate the effect of base surface emissivity on the net rates of radiation heat transfer between the base and the side surfaces, between the...

Q: A piston–cylinder device initially contains 0.2 kg of

A piston–cylinder device initially contains 0.2 kg of steam at 200 kPa and 300°C. Now, the steam is cooled at constant pressure until it is at 150°C. Determine...

Q: Consider a flat-plate solar collector placed horizontally on the flat

Consider a flat-plate solar collector placed horizontally on the flat roof of a house. The collector is 1.5 m wide and 4.5 m long, and the average temperature of the exposed surface of the collector i...

Q: Consider a house that is maintained at a constant temperature of 22

Consider a house that is maintained at a constant temperature of 22°C. One of the walls of the house has three single-pane glass windows that are 1.5 m high and 1.8 m long. The glass (k = 0.78 W/m⋅K)...

Q: A 1-m-diameter spherical cavity is maintained at a

A 1-m-diameter spherical cavity is maintained at a uniform temperature of 600 K. Now a 5-mm-diameter hole is drilled. Determine the maximum rate of radiation energy streaming through the hole. What wo...

Q: An electronic box that consumes 200 W of power is cooled by

An electronic box that consumes 200 W of power is cooled by a fan blowing air into the box enclosure. The dimensions of the electronic box are 15 cm × 50 cm × 50 cm, and all...