K.A.Rajput, A.V.Kulkarni
It is very important to dissipate unwanted heat generated in mechanical devices such as IC engines, radiators, electronic IC’s etc. to the atmosphere. Extended surfaces are widely use in many engineering application because of easy in construction, require less space, light weight. Many new techniques are adopted to improve its effectiveness by reducing the thermal boundary layer thickness and increasing the heat transfer surface area. One of this is perforation through fin body. Limitations of active techniques overcome by passive techniques and researchers find compound techniques is new emerging technique to enhance heat transfer. Now day’s nanotechnology is used in typical cooling applications in many industries by nanostructured coatings, nano porous and nano fin over the surface. It has high thermal conductivity (2000 w/m-k).This article provides a detailed review of heat transfer enhancement by perforation and CNT coating.