A tube bank uses an aligned arrangement of 12-mm diameter tubes with ST = SL = 20 mm. There are 8 rows of tubes with 20 tubes in each row. The tubes are maintained at a surface temperature of 400K, while the flue gas at 300K and a velocity of 5 m/s are in cross flow over the tubes. The properties of the flue gas approximated as those of air at 300K are kinematic viscosity v=15.89x10-6 m/s, k=26.310-3 W/m-K, Pr=0.707, p=1.1614 kg/m, cp=1007 J/kg.K. At 400K, Prs=0.690. Determine 1) Average convention heat transfer coefficient; (10 marks) 2) Rate of heat transfer per unit length of the tubes in the bank. (7 marks)