INTERNATIONAL JOURNAL OF RESEARCH IN AERONAUTICAL AND MECHANICAL ENGINEERING ISSN (ONLINE): 2321-3051 Vol.3 Issue.6, June 2015. Pgs: 12-21 Farooque Azam, Mahendra Dawande , Abhishek Tripathi 12 EXPERIMENTAL AND CFD PREDICTION OF FREE CONVECTION IN A VERTICAL CYLINDER INCLOSED IN A BOX BY FLUENT 14.5 SOLVER USING ROSSELAND RADIATION MODEL AND BOUSSINESQ DENSITY PARAMETER Farooque Azam 1 , Mahendra Dawande 2 , Abhishek Tripathi 3 1 PG (Post Graduate) Student, Mechanical Engineering Department , Bansal Institute Of Research and Technology, Bhopal (M.P.) farooque95@gmail.com, +918982358451 2 Assistent Professor, Mechanical Engineering Department, Bansal Institute Of Research and Technology, Bhopal(M.P.) 3 Abhishek Tripathi, abhiyoho@gmail.com, +919630444300 Abstract In present work the experimental investigation and cfd validation of natural convection in vertical cylinder inclosed in a box is done by FLUENT 14.5 solver. For getting better effect and accurate result Rosseland Radiation Model and Boussinesq density parameter is used. The thermal control in many systems is widely accomplished applying natural convection process due to its low cost, reliability and easy maintenance. Typical applications include the heat exchangers, cooling of electronic equipment and nuclear reactors, solar chimneys and Trombe walls in building industry, etc. Laminar simulations are obtained by solving the governing equations using a Fluent 14.5. It is considered that the temperature variations are not so high and the Boussinesq approximation is applied. It is highly desirable to understand the fluid flow and the heat transfer characteristics of buoyancy-induced micropump and microheat exchanger in microfluidic and thermal systems. In this study different material of pipe (cylinder) is investigated and found that aluminium gives better results then brass material. The experiment was done using brass material and it is validated in cfd and another material i.e. aluminium which replaced brass and then predicted in cfd FLUENT 14.5 solver. Operating conditions and Boundary conditions kept same for brass material and aluminium material. Same Boundary conditions are applied in cfd FLUent, which is used in Experimental investigation. Keywords: Natural Convection, Rosseland Radiation Model, Boussinesq density parameter, FLUENT 14.5