COMPUTATIONAL FLUID DYNAMICS AND HEAT TRANSFER

This is one of the main tools used in the analysis of the systems and processes involved in the R&D activities of the Laboratory. In these, almost always the flow and heat/mass transport phenomena play a decisive role. Some of the most representative problems among those that have been treated so far, are : in the case of water being the storage medium, the transient flow phenomena for natural convection in cylindrical storage tanks in the turbulent flow regime or transition from laminar to turbulent flow and vice versa, as well as in underground rectangular storage tanks, whereby the hydrodynamic behavior has been considered coupled with ground heat transfer (i.e., a conjugate heat transfer problem). The effect of different water inlet-outlet devices such as diffusers of various types (cross-shaped, radial) or baffles has also been considered.
Also problems in applications where air is the working medium have been studied, such as natural convection in trapezoidal cavities which are encountered in greenhouse-type solar stills, and where air has been considered both as pure fluid, as well as a binary mixture, the latter case giving rise to more complex phenomena. Other problems in this category are the flow in solar air collectors with evacuated tubes and the drying in convective-type dryers for agricultural products, in a coupled treatment of the air flow with heat and mass transport.