8.41 Water flows through a thick-walled tube with an inner diameter of 12 mm and a length of 8 m. The tube is immersed in a well-stirred, hot reaction tank maintained at 85 C, and the conduction resistance of the tube wall (based on the inner surface area) is R cd 0.002m2 K/W. The inlet temperature of the process fluid is Tm, i 20 C, and the flow rate is 33 kg/h. (a) Estimate the outlet temperature of the process fluid, Tm, o. Assume, and then justify, fully developed flow and thermal conditions within the tube. (b) Do you expect Tm, o to increase or decrease if combined thermal and hydrodynamic entry conditions exist within the tube? Estimate the outlet temperature of the water for this condition.