Piv study of ventilation quality incertain occupied regions of a 2d room model with rapidly varying flow rates

The use of supply jet flows is the most common type of air distribution for general ventilation inindustrial premises. Usually the supply flow rate is constant or slow varying (VAV-systems) to copewith a varying load. A novel air distribution method, with the potential to reduce stagnation and toincrease the ventilation efficiency, is to introduce rapid flow variations (pulsations). In the paper wereport on a fundamental study of this type of air distribution. The purpose of the study was to explorethe effect on stagnant zones and the levels of the kinetic energy and the relative turbulence intensity.The study was conducted in a small-scale, two-dimensional (2-D) room model with water as operatingfluid. The size of the model made it possible to investigate the 2-D velocity vector field in certainoccupied regions using Particle Image Velocimetry (PIV) method and further consequent analyseshave been done from the resulted vector fields. The comparison between cases of constant inflow andpulsated inflow (flow variations with frequency of 0.5 Hz) have been conducted for three domains,two belonging to the far-field occupied zone and one belonging to the near-field, downstream of thesupply wall jet.