Large eddy simulation of a light gas stratification break-up by an entraining turbulent fountain

ABSTRACT

The erosion process of a stably stratified light gas layer by a vertical turbulent fountain of denser fluid inside a generic containment – for which experimental reference data are available – is studied computationally using large eddy simulation (LES). In addition, various Reynolds averaged Navier–Stokes (RANS) models are applied aiming at a comparative assessment of different computational approaches for the considered case. With the LES methodology included into the present modelling study, a novelty to date is established for fountain-stratification interaction inside generic containments. The high Reynolds number RANS models applied in the framework of this study include both the realisable k–ϵ eddy viscosity model (EVM) as well as the basic Reynolds stress model (RSM). Furthermore, we show that certain regimes of the present configuration can be predicted using an analytically derived scaling approach. Various data beyond the experimentally obtained ones are computationally provided in order to facilitate the calibration of less costly statistical turbulence models and lumped parameter codes, since the presently considered configuration is regarded to be a valuable small-scale equivalent for containment flow applications.

Keywords:

• Stratified flows
• containment flows
• penetrative entrainment
• turbulent buoyant fountains
• large eddy simulation

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The present project was funded by the Federal Ministry for Economic Affairs and Energy (BMWi, project no. 1501463) on basis of a decision by the German Bundestag.