1. This problem touches upon the difference between average heat transfer coefficient and local heat transfer coefficient. You will not need any correlations for this problem. Water is flowing in a pipe (OD = 8 cm, ID = 5 cm). A constant fluid temperature of 24C exists outside the pipe, but the bulk average temperature inside the pipe varies as T(C) = 80 -0.152, where z is the distance (in meters) from the pipe inlet. The outside local heat transfer coefficient is constant at hz = 210 W/m?C and the inside local heat transfer coefficient is given by h = 1210 z 7 W/mC. The thermal conductivity of the pipe material is k = 82 W/mC. a. Calculate the local overall heat transfer coefficient, U2, at z = 2 m, based on the outside pipe area. Hint: we defined overall heat transfer coefficient when discussing thermal resistances. b. Calculate the mean overall driving force (i.e. the average temperature difference between the inside and outside of the pipe), AT, between z= 4 m and z=6 m c. Calculate the mean overall heat transfer coefficient, U2, between z= 4 m and z=6 m, based on the outside pipe area