Fourier heat conduction. Hyperbolic heat conduction. Phase
transition. Forced convection. Natural convection Mixed convection
MHD effects. Non-Newtonian fluids.
The principal research topics are as follows.
a) Heat conduction. I study
the unsteady heat conduction in a semiinfinite medium, by employing
a non-Fourier model for the local energy balance equation based on
a relaxation time. The study is performed analytically. Moreover, I
study numerically the heat exchanged from a buried pipeline, in
presence of freezing /thawing effects in the soil.
b) Laminar forced
convection. In many papers the forced convection is
analytically studied, by employing the complex temperature method,
by taking into account the viscous dissipation effects or the axial
heat conduction effects for the fluid. Then, the analysis is
extended to the case of negligible viscous dissipation or axial
heat conduction effects but taking into account the heat conduction
effect in the channel walls. In this last mentioned paper, I solve
the local balance equation both analytically, by means of the
confluent hypergeometric functions, and numerically. Finally, I
investigate the effect of the viscous dissipation on the laminar
forced convection in ducts having a uniform but arbitrary
cross-section shape, for thermal boundary conditions of kind T, H1
and H2. The mathematical formulation is presented for
arbitrary shapes of the cross-section, but the local balance
equations are solved numerically for stadium-shaped
ducts.
c) Natural and mixed convection
for Newtonian and non-Newtonian fluids. I investigate
analytically the effect of the buoyancy and its interaction with
the viscous dissipation phenomenon, or with magnetohydrodynamcs
effects, or in presence of a steady periodic regime induced
by an unsteady thermal boundary condition. Moreover, I study
numerically the mixed convection in ducts and the natural
convection in enclosures. I investigate analytically the effect of
rheology of fluid on the mixed convection in ducts, for a fluid
having a Bingham constitutive equation. Moreover, I investigate
analytically the mixed convection in an inclined channel, by
releasing the Boussinesq hypothesis.
d) Convection in a fluido saturated porous
medium. The natural and mixed convection Vis
investigated, by employing the different m odels to describe the
fluiddynamics of porous media: Darcy' s law, Brinkman model,
Forchheimer model. Particular attention is devoted to the stability
analysis of some base flows.
