Double-pipe heat exchanger. This type of exchanger is composed of concentric pipes, with how water flowing in the inner pipe while cold water flows in the outer. Hot water enter the inner pipe with a volumetric flow rate of 8L/min, while cold enters at 6L/min. The inner pipe has a diameter of 0.0127m and wall thickness of 0.00076m. The outer pipe has an outer pipe diameter of 0.0190 m and wall thickness of 0.00124m.
1) What is the average velocity of the hot water stream?
2) What is the average velocity of the cold water stream?