Mixed thermal convection: fundamental issues and analysis of the planar case.

This paper aims to renew interest on mixed thermal convection research and to emphasize three issues that arise from the present analysis: (i) a clear definition of the reference temperature in the Boussinesq approximation; (ii) a practical delimitation of the three convective modes, which are the forced convection (FC), mixed convection (MC) and natural (or free) convection (NC); (iii) and, finally, a uniform description of the set FC/MC/NC in the similarity framework. The planar case, for which analytical solutions are available, allows a detailed illustration of the answers here advanced to the above issues.

A new definition of contours in images applications in heat and mass transfer.

A new definition for the contours of objects used in experimental visualization is proposed and used for edge detection and image smoothing in infrared thermography. This work is a contribution to image analysis, in the search for outlines of the features and their structures, aimed at identifying the trends they represent. A good example is the discovery of structures in the flow of liquids.