An experimental investigation of free convection heat transfer rate enhancement of rectangular fins with circular perforations

Fins are popularly applied, for instance, in thermal power plants, space vehicles and air conditioning systems to improve the efficiency of the heat exchangers. Various perforations are made on fins in order to enhance their thermal performance. In the present paper, an experimental work is conducted for investigating the enhancement of heat transfer of rectangular fins with circular perforations. This was conducted under steady state and natural convection condition. The heat transfer coefficient and temperature difference are obtained for different heat generations and at various perforation areas. The results showed that the heat transfer coefficients are generally improved when perforation area is increased. In addition, the temperature differences are decreased with the increase of perforation area. An empirical equation is also developed to predict the Nusselt number in terms of Rayleigh number and perforation area.