5-23 Consider two-dimensional, steady-state heat conduction in a square region of side L subject to the boundary conditions shown in Fig. P5-23. By using a mesh size Ax = Ay =L/3, write the finite- difference formulation of this heat conduction problem. Repeat the analysis by refining the mesh size to Ax - Ay = L/6, and compare the results with those obtained by Ax = Ay = L/3. Calculate the heat transfer rate through the boundary surface at y = 0 per 1-m length perpendicular to the plane of the figure for L = 0.10 m by taking the thermal conductivity as k = 20 W/(mC). - T-200 L T T3 T-300 T TA T-100 T=500 L Figure P5-23