For heat transfer and cooling purposes, a chemical engineering have been consulted to give and advise on fins uses (made of aluminum; k=240 W/m.K) and either select; 1- Rectangular fin with a dimension of 4 cm, 0.5 cm thickness and a length of 3cm 2- For cylindrical fins a radius of 0.25 cm and separation distance of 0.7 cm between fins. The main purpose of using 4 cylindrical finds is to consume less materials. Knowing that heat transfer coefficient is determined to be 40 W/m².K, base temperature is 100°C and the ambient is at 25°C. Which of the two cases, should the engineer consider as best design?

Fig: 1