Questions from Thermal Fluid Science

Q: In a manufacturing facility, 2-in-diameter brass balls

In a manufacturing facility, 2-in-diameter brass balls (k=64.1 Btu/h⋅ft⋅°F, ρ=532 lbm/ft3, and cp =0.092 Btu/lbm⋅°...

Q: Can the thermal resistance concept be used for a solid cylinder or

Can the thermal resistance concept be used for a solid cylinder or sphere in steady operation? Explain.

Q: Consider a sphere of diameter 5 cm, a cube of side

Consider a sphere of diameter 5 cm, a cube of side length 5 cm, and a rectangular prism of dimension 4 cm × 5 cm × 6 cm, all initially at 0°C and all made of silver (k = 429 W/m⋅K, ρ = 10,500 kg/m3,...

Q: Consider a short cylinder whose top and bottom surfaces are insulated.

Consider a short cylinder whose top and bottom surfaces are insulated. The cylinder is initially at a uniform temperature Ti and is subjected to convection from its side surface to a medium at tempera...

Q: An electronic device dissipating 18 W has a mass of 20 g

An electronic device dissipating 18 W has a mass of 20 g, a specific heat of 850J/kg⋅K, and a surface area of 4 cm2. The device is lightly used, and it is on for 5 min and then off for several hours,...

Q: Steam at 280°C flows in a stainless steel pipe (

Steam at 280°C flows in a stainless steel pipe (k = 15W/m⋅K) whose inner and outer diameters are 5 cm and 5.5 cm, respectively. The pipe is covered with 3-cm-thick glass wool insulation (k = 0.038 W/m...

Q: An egg is to be cooked to a certain level of doneness

An egg is to be cooked to a certain level of doneness by being dropped into boiling water. Can the cooking time be shortened by turning up the heat and bringing water to a more rapid boil?

Q: Why are the convection and the radiation resistances at a surface in

Why are the convection and the radiation resistances at a surface in parallel instead of being in series?

Q: Large wind turbines with a power capacity of 8 MW and blade

Large wind turbines with a power capacity of 8 MW and blade span diameters of over 160 m are available for electric power generation. Consider a wind turbine with a blade span diameter of 100 m instal...

Q: What is an infinitely long cylinder? When is it proper to

What is an infinitely long cylinder? When is it proper to treat an actual cylinder as being infinitely long, and when is it not? For example, is it proper to use this model when finding the temperatur...