ANALYSIS OF THERMAL PLUMES GENERATED BY A SEATED PERSON, A THERMAL MANIKIN AND A DUMMY C. P. Borges*, D. A. Quintela, G. N. Brites, A. R. Gaspar and J. J. Costa Departamento de Engenharia Mecânica, Universidade de Coimbra - Pólo II, 3030 Coimbra, Portugal. Tel: 351 239 790 700; Fax: 351 239 790 701 *Instituto Superior de Engenharia de Coimbra – Rua Pedro Nunes, 3030-199 Coimbra, Portugal. Tel: +351 239 790 200; Fax: +351 239 790 270 cmborges@isec.pt; divo.quintela@dem.uc.pt ; goncalo.brites@dem.uc.pt; adelio.gaspar@dem.uc.pt; jose.costa@dem.uc.pt http://www.dem.uc.pt Summary In this work, the main features of the mean velocity and temperature fields developed above different kinds of stationary heat sources, in quiet and isothermal surroundings, are presented and discussed. The major objective of the present contribution concerns the analysis of the modeling capabilities of thermal manikins and heated dummies, as compared to the case of real occupants, engaged on sedentary activities, typical of office work. As it might be expected, the buoyancy driven flow promoted by a thermal manikin (nude or dressed) provides a more sound reproduction of what may be generated by a human being, here restricted to the case of a seated person, normally dressed with common winter clothing. Consideration of the axial decay of mean velocities and temperatures clearly suggest that the development of an axisymmetric turbulent plume originating at a point source is not fully attained. Instead, the flow field seems to be better described by a shear free heated wake, a situation that calls for further analysis. Introduction Understanding of the buoyancy driven flows generated by people engaged on sedentary activities is a matter of particular interest for the removal of air contaminants (Mierzwinsky, 1984). This is particularly true in the case of displacement ventilation. Furthermore, the interactions with other heat sources typical of modern offices, as well as with furniture disposal, may lead to quite different airflow patterns, that must be taken into account, namely when CFD calculations are foreseen. In the present work attention is focused on the thermal plumes generated by an occupant, seated on a common office chair. In order to evaluate their simulation capabilities, a thermal manikin and a heated cylindrical dummy were used for comparison with the results obtained with a person, the first author himself. A comparison between the thermal plumes generated by such distinct heat sources used in this study is outlined. The experimental results presented hereafter are part of a research project actually in course. Figure 1 – Views of the heating sources placed in the centre of the test room with the traversing and probe supporting mechanisms. Preliminary tests with infrared termography are also shown.