Numerical study of natural convection loss from open cavities

► Convective loss from cubical, hemispherical and spherical open cavities analysed. ► Equal heat transfer area for all cavities. ► Effect of wall temperature, inclination and opening ratio on the loss is studied. ► Hemispherical cavities have highest convective loss when compared to other shapes. ► Nusselt number correlation proposed for the convective loss.