RESEARCH AT DFT
DFT research activities are organized and carried out according to the following Research Programs:
The program is devoted to theoretical studies and experimental activity on topics related to building and architectural acoustics and to environmental noise control. Within this context, building elements and materials, HVAC components and machinery for civil and industrial applications are analysed and tested in the Applied Acoustics Laboratory, later described.
Building Physics and Energy Performance in the Built Environment
The research program covers the field of energy simulation of building
and HVAC systems, CFD (Computational Fluid Dynamics) in the built
environment (specifically buildings and tunnels), thermal comfort,
lighting, natural and mechanical ventilation, heat pump applications.
Monitoring and assessment of indoor environmental quality have been
carried out in several buildings both at national and international
level. The group gives assistance and guidelines to design low energy
buildings using also renewable energy, and to establish energy
certification procedures.
Heat Transfer and Pressure Drop during Single-Phase and Two-Phase Flow
The research activities carried out in the years 2002-2006 have mainly regarded the fields of two-phase heat transfer, condensation and vaporisation of refrigerants inside horizontal smooth tubes, microfin and herringbone tubes, multiport microchannels and single minichannels. The working method includes experimentation in two test rigs, flow regime visualization, modelling to provide the designer of compact condensers and evaporators with established procedures based on critical analysis of experimental data. Recent activities cover a new test rig to study air- side heat transfer surfaces for advanced innovative applications and computational fluid-dynamics of two-phase flow.
Refrigeration and Heat Pump Systems and Technology
Under this headline different topics are included, sharing a common interest on the reverse thermodynamic cycles. The approach to the problems covers both the thermodynamic and the technological aspects. The working method includes both theoretical analysis and experimentation. Much of the work concerns the development of numerical simulation models that are used for optimising the design of components, mainly heat exchangers, and for determining the best thermodynamic cycle for different applications. Many investigated topics are suggested from industrial companies which sign contracts to get assistance in developing innovative systems. The main fields of activities are the retail refrigeration and the HVAC, heat pumps systems and refrigeration technology with natural fluids, under the perspective of improving the environmental impact.
It is a new research field for DFT. The program is mainly devoted to solar energy conversion and geothermal systems.
In 2006, new solar energy test rigs have been set up on the roof of DFT, which allow measurements both on solar thermal collectors and photovoltaic systems.
Modelling of components and systems is conducted in parallel, as requested in most cases by companies active in the field of renewable energy. Some planned activity will start soon on solar cooling units and concentrating solar collectors for energy conversion. The research is very focused on the use of new materials and new solutions. Moreover, as regards geothermal systems, detailed modelling has been performed, arriving to the achievement of simplified sizing methods, to be used for the application of such a technology.
Thermodynamic and Transport Properties of Pure Fluids and Mixtures
The program is mainly devoted to the modelling of thermodynamic and transport properties, namely the viscosity and the thermal conductivity, of pure fluids and mixtures. A heat transfer modelling activity for convection at supercritical conditions and for flow boiling inside horizontal tubes was also developed. Most of the target fluids considered in the studies are new generation refrigerants.
Thermophysical properties of building materials
The program is devoted to a thorough analysis of the thermo-physical properties involved in heat and mass (humidity) transfer phenomena inside porous material employed in civil, industrial and historical architecture. The experimental validations of the theoretical and numerical models proposed in heat and mass transfer inside porous building materials are carried out in the Laboratory for Thermophysical Properties (LTP) of the Department, later described.