A copper sphere of 10 mm dia at 80 C is placed in an air stream at 30 C. The temperature dropped to 65 C after 61 seconds. Calculate the value of convection coefficient. Assume property values as...

A copper sphere of 10 mm dia at 80C is placed in an air stream at 30C. The temperature dropped to 65C after 61 seconds. Calculate the value of convection coefficient. Assume property values as follows: density = 8925 kg/m³, specific heat = 397 J/kgK, conductivity = 393 W/mK.

Eq. (3.3).

This method can be used for estimating convection coefficient.