Problem 1: Determine effective heat transfer coefficient, h,, resulting from radiation heat
transfer if the surrounding temperature is 200 °C and the surface temperature is 50 °C with
emissivity of 0.8.
Problem 2: A special-purpose oil flows at $m = 1.81 \times 10^{-2} \frac{kg}{s}$ inside a duct with equilateral
triangle cross-section (side length: 1mm) that is heated electrically at a rate of 76 W/m along the
length direction. At a particular location where the flow and heat transfer are fully developed. For
thermal properties, take $k = 0.139 \frac{W}{m \cdot K}$, $\rho = 854 \frac{kg}{m^3}$, $c_p = 2120 \frac{J}{kg \cdot K}$, and $v = 4.1 \times 10^{-5} \frac{m^2}{s}$.
If convective heat transfer coefficient in laminar flow regime is calculated by $3.1 \frac{k}{D_h}$, Determine
1) The bulk fluid velocity, $V$
2) Reynolds number, Re
3) Convective heat transfer coefficient, h
4) Wall heat flux, $q''$
5) Temperature difference between wall and bulk fluid, $\Delta T$
