A counterflow, concentric tube heat exchanger is used to cool the lubricating oil for large industrial gas turbine engine. The flow rate of cooling water through the inner tube (Di = 25 mm) is 0.2 kg/s, while the flow rate of oil through the outer annulus (Do = 45 mm) is 0.1 kg/s. The oil and water enter at temperatures of 100 and 300 C, respectively. How long must the tube be made if the outlet temperature of oil is to be 600C ?
3. The Attempt at a Solution [/b
Not sure again, sorry