23–111 Hot oil is to be cooled in a multipass shell-and-tube heat exchanger by water. The oil flows through the shell, with a heat transfer coefficient of h, = 35 W/m? · °C, and the water flows...

Extracted text: 23–111 Hot oil is to be cooled in a multipass shell-and-tube heat exchanger by water. The oil flows through the shell, with a heat transfer coefficient of h, = 35 W/m? · °C, and the water flows through the tube with an average velocity of 3 m/s. The tube is made of brass (k = 110 W/m · °C) with internal and ex- ternal diameters of 1.3 cm and 1.5 cm, respectively. Using wa- ter properties at 25°C, determine the overall heat transfer coefficient of this heat exchanger based on the inner surface.