The inner cylindrical R passing through the center of a horizontal cylindrical tube of radius R of length L radius electric heater resistor. The surface temperature of the outer tube is constant T1. inner tube The heat transferred from the walls is constant and So. c) Assuming the inner tube diameter is small enough, the temperature of the water and solution in the annular space Derive expressions that give the distribution. d) Derive the expression for the average temperature of the fluid flowing through the annular space. specify