A tube bank uses an aligned arrangement of 10-mm-diameter tubes with ST = SL = 20 mm. There are 10 rows of tubes with 50 tubes in each row. Consider an application for which cold water flows through the tubes, maintaining the outer surface temperature at 27°C, while flue gases at 427°C and a velocity of 5 m/s are in cross flow over the tubes. The properties of the flue gas may be approximated as those of atmospheric air at 427^oC. What is the total rate of heat transfer per unit length of the tubes in the bank?