Question

Q.3) 34 pts. This problem is to force you to learn and exercise with Grashof Number (Gr #) and natural convection. Gr # is dependent on the position, x, meaning that if there is a certain location where the flow hits turbulent conditions, the convective heat transfer coefficient, h, attains a different value for the rest of the surface. Here, you are to calculate the average h for the wall shown below. The surface of the wall is assumed to have sort of a bell shaped temperature profile, i.e., x2+Bx+C, as shown. The wall height is 3 meters. The air temperature can be assumed as 17 °C The max wall surface temperature can be assumed to be around 45 °C@ x - midway, and the min wall surface temperature can be assumed to be around 20 @ the top and @ the bottom. T=20°C Gr- T=45 °C Air T 20 °C Wall

Answer 1

扌inding average Ausfare temt vatuM 仁。 2 Z. 2 2. B: 15-17

Pas (273 +2 +1リ Ty- 0.00336 2 ) @ 14.7 , No. 6 m"7s 17.C's 0 0033 6 x 15.ux 901 3