Experiment of Water Tank Model for Displacement Ventilation Using Image Processing

Displacement Ventilation offers improved air quality and high ventilation effectiveness, and reduces air-conditioning costs relative to conventional Diffusion Ventilation. However, it is difficult for traditional techniques to measure flow velocity, temperature and tracer concentration to evaluate the characteristics of displacement ventilation since it is influenced by natural convection and has a complex flow field In this study, a series of experiments to measure flow velocity, temperature and tracer concentration distribution was performed for geometrically similar scale water tank model of room space equipped with displacement ventilation by applying image processing techniques. The distribution of local air exchange effectiveness was calculated from temporal change of tracer concentration distribution by the step-down method. It was confirmed that PTV for velocity measurement and tracer concentration measurement for local air exchange effectiveness calculation were useful to evaluate the characteristics of DV The dynamic range of liquid crystal thermometry should be expanded.