Turbulence in real flammable gas releases

Abstract : The research activities in AIRRE project (Assessing the Influence of Real Releases on Explosions) include a unique series of large-scale explosion experiments with ignited high-momentum jet releases of natural gas directed into congested geometries. The primary objective for the AIRRE project is to gain improved understanding of the effect realistic releases and turbulent flow conditions have on the course and consequences of accidental gas explosions in the petroleum industry, and thereby develop and commercialize technology and methodology that can facilitate safe and optimal design of process facilities. A few tests were performed in open air without any congestion. The mean velocity and turbulence flow fields are presented herein. Flameproof turbulence sensors were purposely designed for the project and calibrated at small scale. These are Pitot probes connected to fast differential pressure sensors. This paper describes the turbulence measurement technique used and highlights the specific issues related to the data post-processing in order to calculate the turbulence intensity and the turbulent length scale. Test results are analysed, and comparisons are made with free jet experiments at small scale, and related jet theories.