Investigation of mean scalar characteristics of vertical buoyant gas plume inside a gas chamber with multiple sensors*

A low-cost university-scale gas chamber with the capability to vary inlet nozzle diameter, momentum and buoyancy fluxes at the inlet is designed and fabricated at the Laboratory of Turbulence, Sensing and Intelligence systems at the University of Texas at San Antonio. The gas chamber is equipped with an array of 40 temperature and gas sensors positioned radially about the centerline of the plume at a given height from the inlet. The purpose of the chamber is to study the relation between vertical buoyant plume scalar half-width growth with respect to the source Reynolds number (Re_o) and densimetric Froude’s number (Fr_o). Heated Carbon Dioxide is used as a tracer gas and is forced into a still air environment inside the chamber. Temperature and gas concentration data were collected at multiple heights, all beyond 10 times Morton’s momentum length, to estimate the plume half-width growth. Multiple experiments were conducted with varying inlet buoyancy to momentum ratio (<1, >1 and =1) to obtain the desired Re_o and Fr_o.