Abstract
Natural convection in cavities has been a field of interest to researchers over the past 50 years. One of the basic techniques used to investigate the natural convection in cavities is shadowgraph flow visualisation, used to experimentally observe the boundary layer growth, formation of double layer structures, intrusions and plume generation. This paper accounts for Various other observations also made when fins are placed along the side wall of the cavity, the effect due to change in shape and orientation of the cavity, how these changes effect the natural convection have also been discussed. The applications of various types of shadowgraph methods to understand the flow variation with density have also been included. The paper summarizes the literature of shadowgraph techniques in natural convection.