httc

A surface has no mass or volume, but it can store energy. TF

F

Radiation heat transfer needs presence of an intervening medium for heat to flow. TF

F

A blackbody has an emissivity of ....

1

The heat flux on the two sides on an interface must be the .....

same

For heat generation in a solid sphere, the maximum temperature will be at the 

center

Convection resistance increases with h. TF

F

The purpose of the bony plates on the back of stegosaurus was to 

cool it down

Minimum fin effectiveness needed to justify adding a fin is ....

2

What value of mL in an infinite fin will give ~90% heat transfer

1.5

Bi is the ratio of strength of .............

convection over conduction

If h is infinite, it means surface temperature is equal to

fluid temp

When will velocity and thermal boundary layers overlap?

Pr=1

For laminar flow over flat plate the average Nu is ....the local value.

twice

During flow over cylinders or spheres, the heat transfer coefficient does not vary on the surface between the stagnation point and the wake region. TF

F

Temperature of the fluid during internal flow increases linearly when the boundary condition at the wall is 

constant surface heat flux

Dittus-Boelter equation applies to what type of flow?

tubulent

Viscous dissipation is important in ......

high speed flow

In a vertical cylinder, if curvature effects are negligible, you can treat is as a ....

vertical plate

The surface temperature of the sun is approximately ...

5800 k