Wind-tunnel experiments on atmospheric heavy gas dispersion: Metrological aspects

We propose a new experimental protocol to investigate the atmospheric dispersion of dense gas in wind-tunnel experiments. Simultaneous measurements concentration and velocity are performed by coupling flame ionisation detector (FID) hot-wire anemometer (HWA), whose probes located sufficiently close each other so that respective correspond same sampling volume. The heavy emission consists mixture air, carbon dioxide, ethane. Carbon dioxide is used as buoyant agent, ethane tracer, its being detected FID. In this context, main metrological issue setup concerns response FID HWA different proportions two gases mixture. Notably, presence affects linear FID, which can attain saturation level, well HWA, due varying density gas. This be compensated determining non-linear calibration curve determine instantaneous fluid density, apply time-dependent correction response. To analyse performances coupled HWA–FID system we realised experiments tracer turbulent boundary layer. estimate mass fluxes through sections downwind source enlightens reliability results, show within negatively plume accurate those passive scalar plume.