Question

A flat plate has a length L = 1 m and experiences air flow parallel to the surface. Transition from laminar to turbulent flow occurs at xc = 0.5 m. The critical Reynolds number is Rex, c = 5 × 105. (a) If the film temperature is 350 K, what’s the air velocity? (b) The local convection coefficient for laminar flow is given by

Answer 1

Answer:

velocity is 15.083 m/s

Explanation:

given data

length L = 1 m

Laminar to turbulent flow

xc = 0.5 m

Reynolds number Rex, c = 5 × $10^{5}$  

solution

we take here for 350 K

$\mu$  = 1.81 × $10^{-5}$  

and here   Reynolds number Rex, is express as

Rex = $\frac{\sigma \times v \times x}{\mu }$   ................1

put here value at x = 0.5

5 × $10^{5}$   = $\frac{1.2\times v \times 0.5}{1.81\times 10^{-5} }$  

solve it we get

v = 15.083 m/s

so velocity is 15.083 m/s