The average heat transfer coefficient for air flow over an odd-shaped body is to be determ...

The average heat transfer coefficient for air flow over an odd-shaped body is to be determined by mass transfer mea- surements and using the Chilton-Colburn analogy between heat and mass transfer. The experiment is conducted by blow- ing dry air at 1 atm at a free stream velocity of 2 m/s over a body covered with a layer of naphthalene. The surface area of the body is 0.75 m2, and it is observed that 100 g of naphthalene has sublimated in 45 min. During the experiment, both the body and the air were kept at 25°C, at which the vapor pressure and mass diffusivity of naphthalene are 11 Pa and DAB = 0.61 × 10–5 m2/s, respectively. Determine the heat transfer coefficient under the same flow conditions over the same geometry.