ABSTRACT:Heat energy plays most important role in the field of power generation which involves the heat transfer in domestic as well as industrial purposes. Literature shows the heat transfer coefficient between heat transferring surface and air is low which leads to lower thermal efficiency of the system. Therefore it is important to increase heat transfer coefficient between heat transferring surface and air. The most promising technique to enhance heat transfer coefficient is artificial roughness on heat transfer field. Artificial roughness applied on the absorber plate is the most acclaimed method to improve thermal performance of solar air heaters at the cost of low to moderate friction penalty. Experimental investigations pertinent to distinct roughness geometries unfolds that the enhancement in heat transfer is accompanied by considerable rise in pumping power. In view of the fact, a designer needs to carefully examine shape and orientation of roughness elements in order to choose the best fit roughness geometry for intended application. This dissertation work will cover the types of technique used in enhancing the heat transfer coefficient in field of heat transfer and thermal efficiency.