9) In a heating system, steam flows through pipes with a diameter of 5 cm, the walls of which are kept at 180 C. Circular aluminum 2024-T6 alloy wings with an outer diameter of 6 cm and a fixed thickness of 1 mm for pipes (k=186 W/m.C) is installed. The Decoupling space between the flaps is 3 mm; therefore, the meter of the pipe is there are 250 wings per length. The temperature is 40 W/m2 to the ambient air at Ta=25C.C it is transferred with a heat transfer coefficient. Unit length due to the added wings find the increase in heat transfer from the pipe per. 2.5cm 1 To=253 cm 180C FIGURE P9 mm1 3 mm