Simulation of water vapour condensation in a partly closed structure by using digitized experimental results

Abstract

Our aim is to determine the more significant parameters acting on the water vapour condensation in a partly closed structure, submitted to external constraints (temperature and humidity). These constraints locally lead to condensation of the water vapour, initially contained in the air of the volume and/or on the walls. Previously we have presented the results obtained in two papers. In the first one [1], by using a simplified model in which the inside bottom wall was remained dry, we highlighted the role of external parameters such as the Relative humidity RH and the Temperature T. In the second paper [2] comparison was made between the role played by the presence of a small layer of water on the structure bottom wall and the results previously obtained in the case of a dry bottom. From these results it appeared that condensed water quantities depend on: 1) dimensions of the structure, 2) the air humidity and its renewing under the action of the outside-inside thermal gradient, 3) the phase (φ = T/RH) between thermal and hydrometric conditions. These results highlighted that peculiar conditions are needed to obtain a maximum of condensation. On this basis, by using our modelling and by digitizing a lot of meteorological data, locally registered, we have attempted to determine the quantity of condensed atmospheric water vapour which can be obtained inside a similar structure. Now we present the results obtained by using the meteorological data recorded during the year 1999 by Beysens and al [3]. Comparison is made with the quantities of condensed water vapour values estimated by this author and which could be obtained inside the Arles-sur-Tech sarcophagus (France (66)).