The course aims at introducing the basic theory and applications of heat transfer, focusing in particular on thermal issues of electronic devices. For this reason, lessons are supported by (optional) computer labs to develop fundamentals of thermal analysis by FEM software packages.
Lessons (theory and applications)
1) Review of thermodynamics. Systems, equilibrium states, intensive and extensive properties, first and second principle, internal energy, heat, work, entropy.
2) Introduction to transport phenomena. Concept of continuum, non-equilibrium states, local equilibrium. The basic mechanisms of heat transfer: conduction, convection and radiation.
3) Conduction. Fourier’s postulate, Fourier’s equation, dimensional analysis: Biot and Fourier numbers. Steady-state temperature distribution in simple bodies, thermal resistance networks. Fin design. Transient analysis for simple bodies: lumped parameters versus distributed parameters.
4) Introduction to convection. Balance equations for a moving continuum. Laminar and turbulent flow. Hydrodynamic and thermal boundary layer.
5) Forced convection. Dimensional analysis: Reynolds, Prandtl and Nusselt numbers. Correlations between the dimensionless groups for external and internal flows. Introduction to heat exchanger design.
6) Free convection. Buoyancy, dimensional analysis: Grashof, Rayleigh and Nusselt numbers. Correlations between the dimensionless groups.
7) Radiation. Thermal radiation, blackbody radiation, radiative properties of real bodies. Kirchhoff’s law, grey bodies. Radiation heat transfer among grey bodies: view factor, resistance networks.
Computer Labs (not mandatory for the final exam)
1) Introduction to the Heat Transfer Module of Comsol Multiphysics®.
2) Modelling steady-state heat conduction.
3) Modelling transient heat conduction.
4) Modelling boundary layers.
5) Thermal analysis of electronic devices (optional project).