Chapter 9, Problem 9.11P

To determine

To show: Average heat transfer coefficient is expressed as ${\overline{h}}_L=1.40{\left(\frac{\Delta T}{L}\right)}^{1/4}$ for ${10}^4<{\text{Ra}}_L<{10}^9$ and ${\overline{h}}_L=0.98\Delta T^{1/3}$ for ${10}^9<{\text{Ra}}_L<{10}^{13}$ .