Transient free convection and thermal stratification in uniformly-heated partially-filled horizontal cylindrical and spherical vessels

An integral approach has been used to analyze the development of the free convection boundary layer on heated concave surfaces, such as those in horizontal cylinders or a sphere. Based on the non-dimensional laminar and turbulent velocity and temperature profiles closed form expressions for the boundary layer thickness, velocity scale as well as the boundary layer commencement after the point of instability are obtained. In addition, the mass flowrate to the thermal stratified region is given.