[1] Assistant Professor,

Abstract—Liquid or gas flow through pipes or ducts is commonly used in heating and cooling applications and fluid distribution networks.the fluid in such application is usually forced to flow either by a fan or pump. It is a common practice at most of the fluid especially liquids are transported through circular pipes. This is because pipes with circular cross section can withstand large pressure difference between inside and outside without undergoing significant distraction.non circular pipes are usually used in applications such as heating and cooling of buildings,where the manufacturing and installation costs are lower and the available space is limited for non circular duct work. As the fluid properties vary with temperature and location, the value of convective heat transfer coefficient (h) also varies.presently there are many correlations to predict heat transfer from heated vertical and horizontal pipes in both forced and natural convection situations. A review of literature on heat transfer coefficient (h) indicated that very little work has been done on inclined pipes in the recent past with little or no conclusive work reported for flow through an inclined pipe with square cross section. Using the fabricated experimental setup convective heat transfer coefficient of air passing through square duct was determined under the following conditions. a) Constant heat input and varying the air velocity. b) Constant air velocity and varying heat input c) Constant heat input and air velocity by varying the angle of inclination of duct. d) Keywords—liquid, gas, convective heat transfer coefficient, tempareture, turbulent flow, reynolds number, nusselt number