Consider atmospheric air at 20°C and a velocity of 30 m/s flowing over both surfaces of a 1-m-long flat plate that is maintained at 130°C. Determine the rate of heat transfer per unit width from the plate for values of the critical Reynolds number corresponding to 105 , 5 × 105, and 106 .

Explanation:

We are given:

T_o = 20°C

Flat plate temp, T_s = 230°C

v = 30m/s

Let's find the mean:

= 75°C

Using air table at 75°C at 1 atm pressure, we have:

Prandtl number, Pr = 0.7087

Calculating Reynolds number, we have:

Since the Reynolds number is higher than the critical Reynolds number, we can say there is a turbulent flow.

Therefore we'll now use the formula:

To get A using the formula, we have:

= 160.024

= 2646.78

Connective heat transfer:

Lets calc for heat transfer:

= 2(78.50)(1)(130-20)

= 1720W/m

= 871.323

Calculating Nu_L we have:

= 59.672W/m²•K

For the heat transfer:

= 13127.84W/m

= 1670.54

Calculating Nu_L:

= 1298.51

Calculating the convective heat transfer coefficient:

=38.51 W/m²•K

To calculte for rate of heat transfer, we have:

=2(38.51)(1)(130-20)

= 8472.2W/m

answer:

put more,

answer:

a

explanation: