Steam in a heating system flows through tubes whose outer diameter is 5 cm and whose walls are maintained at a temperature of 130 ◦c. circular aluminum alloy 2024-t6 fins (k = 186 w/m · k, ηf = 0.97) of outer diameter 6 cm and constant thickness 1 mm are attached to the tube. the space between the fins is 3 mm, and thus there are 250 fins per meter length of the tube. heat is trans- ferred to the surrounding air at t[infinity] = 25 ◦c, with a heat transfer coefficient of 40 w/m2 · k.
determine the increase in heat transfer from the tube per meter of its length as a result of adding fins.