Chapter 3, Problem 3.73P

The energy transferred from the anterior chamber of the eye through the cornea varies considerably depending on whether a contact lens is worn. Treat the eye as a spherical system and assume the system to be at steady state. The convection coefficient $h_o$ is unchanged with and without the contact lens in place. The cornea and the lens cover one-third of the spherical surface area.

Values of the parameters representing this situation are as follows:

   $\begin{array}{l}{r}_1=10.2\text{mm}{r}_2=12.7\text{mm}\\ r_3=16.5\text{mm}{T}_{\infty ,o}=21°\text{C}\\ T_{\infty ,i}=37°\text{C}{k}_2=0.80\text{W/m}\cdot \text{K}\\ k_1=0.35\text{W/m}\cdot \text{K}{h}_o=6{\text{W/m}}^{\text{2}}\cdot \text{K}\\ h_i=12{\text{W/m}}^{\text{2}}\cdot \text{K}\end{array}$

1. Construct the thermal circuits. labeling all potentials and flows for the systems excluding the contact lens and including the contact lens. Write resistance elements in terms of appropriateparameters.
2. Determine the heat loss from the anterior chamber with and without the contact lens in place.
3. Discuss the implication of your results.