Free convection velocity. 

(a) Verify the expression for the average velocity in the upward-moving stream in Eq. 10.9-16. 

(b) Evaluate β for the conditions given below. 

(c) What is the average velocity in the upward-moving stream in the system described in Fig. 10.9-1 for air flowing under these conditions? 

Pressure                                                               1atm

Temperature of the heated wall                      100°c

Temperature of the cooled wall                       20°C 

Spacing between the walls                                0.6 cm

Transcribed Image Text:

Surface temperatures of plastic panel -T2 = 61°F - T¡ = 69°F T3 = 0°F- Wall - Plastic panel has thermal conductivity k = 0.075 Btu/hr ft °F (average value between T1 and T2) –6"- 0.502"