Dry air at 20°C and a velocity of 15 m/s flows over a 20-mm-diameter rod covered with a thin porous coating that is saturated with water. The rod (k = 175 W/m ∙ K) is 250 mm long and its ends are attached to heat sinks maintained at 35°C.

Perform a steady-state, finite-difference analysis of the rod-porous coating system, considering conduction in the rod as well as energy transfer from the surface by convection heat and mass transfer. Use the analysis to estimate the temperature at the mid span of the rod and the evaporation rate from the surface. (Suggestions: Use 10 nodes to represent the half-length of the system. Estimate the overall average convection heat transfer coefficient based on an average film temperature for the system, and use the heat-mass transfer analogy to determine the average convection mass transfer coefficient. Validate your code by using it to predict a temperature distribution that agrees with the analytical solution for a fin without evaporation.)

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Rod with porous coating, D = 20 mm L= 250 mm T = 35°C Heat sink Dry air T = 35°C V = 15 m/s T = 20°C %3D