4) (35pts) Cooling Silicon Ingots of Different Diameter You have two silicon ingots with different geometries cooling from an initial temperature of T. (ingot) = 1600K, with a fan providing a

crossflow air stream leading to a convective heat transfer coefficient of h = 150 W/m²-K with Tair = 20°C. Geometry: Large Si Ingot D=300mm and L=2 m; Small Si Ingot D= 75mm and L=1m Silicon Properties (1600K): k-30.0 W/m-K; p=2300 kg/m³; Cp=1000 J/kg-K; a = 1.3x10-5 m²/s For each silicon ingot do the following: a) Sketch and label the problem. State all Assumptions. List Given information. b) Calculate L/D and Biot # for each silicon ingot (assume R/2 for Biot# calculation). c) Determine the surface and center temperatures of each silicon ingot at t = 15 minutes. NOTE: End effects CAN be neglected. d) Determine the surface and center temperatures of each silicon ingot at t = 15 minutes. NOTE: End effects CANNOT be neglected (unless justified).