Answer:
[tex]q=11.37 \frac{KW}{m^2}[/tex]
Explanation:
Given that velocity=6 m/s
Temperature of surface=75 °C
Temperature of air=25 °C
Reynolds number =[tex]5\times 10^5[/tex]
It means that this is laminar flow.So Nusselt equation given as follows
[tex]Nu=0.644Re^{\frac{1}{2}}Pr^{\frac{1}{3}}[/tex]
Now properties of air at mean temperature of 75 °C and 25 °C (50 °C) is taken from standard table
K=0.028 W/m-K,Pr=0.71
And we also know that
[tex]Nu=\dfrac{hL_c}{K}[/tex]
Now by putting the values
[tex]Nu=0.644\times (5\times 10^5)^{\frac{1}{2}}\times 0.71^{\frac{1}{3}}[/tex]
Nu=406.24
[tex]406.24=\dfrac{h\times 0.05}{0.028}[/tex]
[tex]h=227.49 \frac{W}{m^2K}[/tex]
So heat flux q= hΔT
q=227.49 x (75-25)
[tex]q=11.37 \frac{KW}{m^2}[/tex]
