01. Experimental/Computational Fluid Dynamics

The COVID-19 epidemic has generated an increased interest in air conditioning and ventilation in enclosed spaces. Jet stream technology has been identified as a key technology for personal air conditioning and next-generation ventilation, and many researchers have investigated the basic flow characteristics of jets in passenger cabins of vehicles. Several researchers investigated the flow characteristics of jets near a plane wall, which represents the simplest boundary condition. Recently, studies have been conducted on the flow characteristics of jets passing through a row of two-dimensional planar plates, focusing on the recirculation region in each cavity. However, there have been no systematic studies on the relationship between geometric boundary conditions such as plate spacing and the flow field, and many uncertainties remain. In this study, the distance between the jet outlet slot and the tip of the flat plate was kept constant under conditions where the Coanda effect appeared, and the flat plate length and the flat plate spacing were investigated as parameters. This study involves fundamental research for improving the efficiency of air conditioning and ventilation systems. The inflow into the cavity and jet deflection characteristics were discussed through numerical simulations and visualization observations. It was shown that maxima and minima (extrema) existed in the cavity inflow, and the conditions under which the jet flow changed significantly were deduced for plate length and plate spacing as parameters.