RICERCA ITALIANA     

Research program

Innovative techniques for the enhancement of forced convection

University Co-ordinator

Università degli Studi di PARMA - INGEGNERIA INDUSTRIALE - ()

Research Unit Leader

Sara Rainieri

Description

The here presented research deals with the procedures aimed to the estimation of the convective coefficient under the condition of surface vapour condensation, based on the resolution of the inverse heat conduction problem in the wall.
To the purpose of applying this methodology, the temperature will be acquired with infrared thermographic systems. Some reference wall points will be equipped with contact thermocouples, too. The research project will develop in two sequential phases, each to be completed within approximately one year.
The proposed research has an essentially experimental character. The activities will be performed predominantly within the Experimental Laboratory of the Industrial Engineering Department of the University of Parma. The Laboratory is equipped with the main instrumentation for the measurements of the basic thermo-physical quantities of interest to the present research. The Laboratory staff includes technicians which do not have specialized abilities and the required scientific background in relation to the argument and objectives of the present research project.
The research budget will be in part employed to recruit qualified persons who will cooperate with the academic team in the experimental activity. In particular, this cooperation will promote also the training of a young engineer towards the research activity.


First year
A wide effort will be devoted to the assessment of the available heat transfer enhancement techniques for forced air convection in wet conditions. The most widespread ones will be then tested inside a moist air flow loop, with the aim of comparing the estimated heat transfer performances with the literature data. The temperature maps will be acquired by an infrared camera and by temperature contact sensors, too. The data processing will be performed in Matlab and COMSOL Multiphysics environments.
Besides the temperature maps, also the photographic pictures of the surface where water vapour condensation occurs will be acquired, with the aim of pointing out the processes of formation, growth and drainage of the condensate.

Second year
The estimation procedure will be applied to the analysis of the heat transfer performance of further hydrophobic coatings. Besides smooth walls, also heat transfer enhancing walls will be tested.
To make easier the understanding of the experimental results, the photographic pictures will be analysed in connection with the results of the thermal analysis.
The obtained results regarding the local heat transfer coefficient will be interpreted and discussed also within the international scientific community, in relation to the data available in the open literature on the performance of the heat transfer apparata in which the simultaneous heat and mass convective transfer occurs.

Synergies with the other research units.
The here presented research will be performed with a specific coordination with the the other units taking part to the Program.
The experiences on the numerical methodologies acquired by the other research units, with commercial and self-written codes, will promote and interesting discussion on the thermal performances obtainable by the various typology of enhanced surfaces.
The information interchange with the research units which adopt experimental methodologies will activate also a significant synergies regarding the various investigation tehcniques.
In particular, the experimental methodology and the results will be discussed and compared with the research units of Bologna and Milano; the former, like the present unit, employs the infrared thermography, even if with a different data processing procedure, the latter intends to investigate by means of conventional and optical techniques the heat transfer also in dehumidifying conditions in wavy channels.
In the second phase of the research a specific interaction will be performed with the unit of Udine, who focuses its activity on the numerical simulation of the combined heat and mass transfer aimed to the modelling of compact heat exchangers.