as a guide, prepare a similar table showing the order of magnitudes of the thermal resistances of a unit area for convection between a surface and various fluids.
GIVEN
• The order of magnitude of convective heat transfer coefficient ( h c)
FIND
• The order of magnitudes of the thermal resistance of a unit area (A Rc)
The thermal resistance for convection is defined by
Therefore the thermal resistances of a unit area are simply the reciprocal of the convective heat
transfer coefficient
As an example, the first item in Table 1.4 is ‘air, free convection’ with a convective heat transfer
coefficient of 6–30 W/(m2 K). Therefore the order of magnitude of the thermal resistances of a unit
area for air, free convection is
The rest of the table can be calculated in a similar manner
You might also like to view...
The shorter a wave's wavelength, the greater its energy
Indicate whether the statement is true or false
An X-ray telescope placed on the surface of Earth can detect X-rays that are emitted from a distant astrophysical source.
Answer the following statement true (T) or false (F)
Two charged bodies separated by a distance d exert a repulsive electrical force on each other. The signs of the charges on the two bodies are + and –
Indicate whether the statement is true or false
A 50-kg child riding a Ferris wheel (radius = 10 m) travels in a vertical circle. The wheel completes one revolution every 10 s. What is the magnitude of the force on the child by the seat at the highest point on the circular path?
a. 0.29 kN b. 0.49 kN c. 0.69 kN d. 0.20 kN e. 0.40 kN