Develop an expression for the ratio of the rate of heat transfer to water at 40C from a thin flat strip of width D/2 and

Develop an expression for the ratio of the rate of heat transfer to water at 40°C from a thin flat strip of width πD/2 and length L at zero angle of attack and a tube of the same length and diameter D in cross-flow with its axis normal to the water flow in the Reynolds number range between 50 and 1000. Assume both surface are at 90°C.

GIVEN

• Water flowing over a thin flat strip at zero angle of attack or a tube in crossflow
• Water temperature (T_∞) = 40°C
• Tube diameter = D
• Strip width = πD/2
• Tube and strip length = L
• Reynolds number: 50 < Re < 1000

ASSUMPTIONS

• Steady state for both cases
• The tube and strip temperatures (T_s) are 90°C

-90C Water T= 40C Strip -D- T = 90C Water T.- 40C Tube