. A parallel flow concentric tube heat exchanger is used to cool engine oil with water. The unit has not been serviced in a long time. The factory design specification tell us the overall heat transfer coefficient of a new heat exchanger is Ud=50W/m2. The diameter of the inner tube is0.03m with a length of 30m. Determine if fouling has occurred based on the current test results given in the figure below. Draw a plot of the temperature profile on both the hot and cold side given the temperature of the inlet and outlet and the flow configuration. (Use LMTD method)

Fig: 1

Fig: 2