摘要

This lecture aims to place again the mixed thermal convection in the center of the convection heat transfer and to emphasize three issues that arise by this approach: (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 (free) convection (NC); (iii) and, finally, a uniform description of the assembly FC/MC/NC in the similarity framework. Two examples are analyzed : plane and annular channels, for which analytical solutions are available. They allow a detailed illustration of the proposed answers to the above issues, and permit to define characteristic scales in mixed convection. The case of mixed convection in nanochannels is also examined.