DIFFERENT APPROACHES FOR THE SIMULATION OF AN EXPERIMENTAL BUILDING HOSTING A CLIMATE CHAMBER DEVOTED TO ARTIFICIAL FOG PRODUCTION

摘要

In the context of a european project dealing with the issue of transport safety improvement in fog conditions, an experimental building has been constructed on the FUL campus, in the southern part of Belgium. This building hosts a climatic chamber in which a given indoor climate is to be maintained (temperature and relative humidity) whatever the external climate, in order to promote the artifical production of fog by water droplets spraying. During the design of the building and of the HVAC plant, different simulation approaches were carried out in order to evaluate and possibly optimize the technical choices concerning: - the building envelope - the material for the climatic chamber - the control strategy of the HVAC system Two categories of simulation tools were used to solve the different tasks: - building simulation tools - CFD programsFor the first category, simulations were performed using both ESP-r and TRNSYS with the objective of solving the following questions: optimization of the building envelope (orientation and shading of the building, insulation, fenestration); sizing of the HVAC system; comparison of control strategies (direct control, indirect control, radiative and/or convective conditioning); estimation of energy consumption and comfort Within the second category, the FLUENT and ESP-r software were used and compared in order to predict the homogeneity of the thermal state within the test room and to calculate the effect of injecting a high amount of small water droplets on fog production, maintenance and visibility. Therefore, the ESP-r CFD module program was augmented with a specific model of water droplet diffusion. The paper will tackle the main modelling assumptions at the basis of each simulation experiment, the data preparation and the results of the calculations. For each phase, advantages and limitations of the simulation approach will be highlighted.These developments are considered as a first step towards the implementation of a virtual testing environment in the field of automotive transport which could be complemented by additional issues dealing with passengers comfort, acoustics, air quality, level of illuminance generated by the virtual production of fog.