Further development of a model for dense gas dispersion over real terrain

Cleaver, R.P.; Cooper, Myra; Halford, Ann

doi:10.1016/0304-3894(94)00081-q

Cited by 8 publications

(4 citation statements)

References 5 publications

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“…8 Box models were used to describe heavy gas dispersion with instantaneous releases. 9,10 Usually, the pollution cloud was assumed to form a uniform cylinder with a specified size. The concentration average for the box volume was calculated based on the mass of the substance released and the box volume.…”

Section: Introductionmentioning

confidence: 99%

Performance evaluation by computational fluid dynamics modelling of the heavy gas dispersion with a low Froude number in a built environment

Zhang

Wang

et al. 2019

Indoor and Built Environment

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To evaluate the dispersion of a heavy gas, such as sulphur hexafluoride, with a low Froude number in a built environment, an experimental and numerical simulation study was conducted. The experiment was carried out using seven different injection inlet configurations in an experimental chamber. The release rate was found to have a great effect on the concentration in the lower part of the chamber. The obstacle in the middle of the chamber could cause a non-uniform distribution of concentration, particularly due to variations in locations and angles of the release outlets. Additionally, numerical simulations were carried out to evaluate four turbulence models: the standard k- ε model, the realizable k- ε model, the re-normalization group (RNG) k- ε model and the shear stress transport (SST) k-ω model. Four indicators were used to evaluate the turbulent model performance. In general, the SST k-ω model performed the best, with geometric mean bias ( MG) = 0.968 and geometric variance ( VG) = 1.09 at 0.055 m height, and with MG = 0.384 and VG = 2.80 at 0.6 m height. The standard k- ε model was the next best in performance, followed by the realizable k- ε and the RNG k- ε model.

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Section: Introductionmentioning

confidence: 99%

Performance evaluation by computational fluid dynamics modelling of the heavy gas dispersion with a low Froude number in a built environment

Zhang

Wang

et al. 2019

Indoor and Built Environment

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“…The modeling of discharge at the rupture plane for single- or two-phase fluids has been the subject of a number of studies. − Depending on their level of sophistication in terms of, for example, accounting for various pertinent phenomena such as heterogeneous flow behavior and phase dependent in-pipe heat transfer and frictional effects, reasonably good agreement with real pipeline rupture data has been reported. Dispersion modeling of escaping buoyant or heavy clouds on the other hand is a mature subject having received considerable attention in the past decades. − However, the analytical modeling of the intermediate stage, i.e, the jet expansion to the ambient pressure, is often based on simplistic physical approximations such as isenthalpic or isentropic jet expansion immediately downstream of the rupture plane. , This is a considerable drawback given that the predicted fully expanded conditions form the boundary conditions needed for the downstream dispersion simulation. The importance of the correct modeling of the jet expansion was clearly demonstrated in a study of the dispersion behavior of a flashing jet by Calay and Holdo using CO 2 as the working fluid.…”

Section: Introductionmentioning

confidence: 99%

“…Depending on their level of sophistication in terms of for example accounting for various pertinent phenomena such as heterogeneous flow behavior and phase dependent in-pipe heat transfer and frictional effects, reasonably good agreement with real pipeline rupture data has been reported. Dispersion modeling of escaping buoyant or heavy clouds on the other hand is a mature subject having received considerable attention in the past decades 11,12,13 . However, the analytical modeling of the intermediate stage, i.e.…”

Section: Introductionmentioning

confidence: 99%

Integral Multiphase Turbulence Compressible Jet Expansion Model for Accidental Releases from Pressurized Containments

Zheng

Mahgerefteh

Brown

et al. 2016

Ind. Eng. Chem. Res.

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The accurate prediction of the conditions of a pressurized jet upon its expansion to atmospheric pressure is of fundamental importance in assessing the consequences associated with accidental releases of hazardous fluids from pressurized containments. An integral multi-phase compressible jet expansion model which for the first time accounts for turbulence generation is presented. Real fluid behavior is accounted for applying a suitable equation of state. Using the accidental release of two-phase CO 2 from a pressurized system as an example, the proposed model is shown to provide far better predictions of the fully expanded jet momentum, and hence its downstream flow characteristics as compared to existing integral models where the impact of turbulence generation is ignored.

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“…Examples of box models are presented in Table 1. The steady state plume models are used for continuous grounded releases [33,34,39,[50][51][52][53]. The first models of this group were created in the late seventies.…”

Section: Intermediate/integral and Shallow Layer Modelsmentioning

confidence: 99%

A Review of Mathematical Models for the Atmospheric Dispersion of Heavy Gases. Part I. A Classification of Models

Markiewicz¹

2012

Ecological Chemistry and Engineering S

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Abstract:In this two part article in its first part models of heavy gas dispersion in the atmosphere are classified and the distinguished groups of models are characterised. In the second part the procedures for the model quality evaluation are described and the main results of model evaluation projects are summarised. Substances released to the atmosphere which have a density greater than the density of the atmospheric air are called heavy gases or dense gases. The dispersion of heavy gases is different from that encountered in the case of neutrally or positively buoyant gases. Specific models have been developed to describe it. The heavy gas dispersion models differ in the complexity and mathematical description. Based on these criteria four main groups of models are distinguished: simple/empirical models, intermediate/integral and shallow layer models, advanced/Lagrangian particle trajectory and Lagrangian puff dispersion models and sophisticated/Computer Fluid Dynamics (CFD) models. This classification is an extension of the classification proposed earlier in the literature.

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Further development of a model for dense gas dispersion over real terrain

Cited by 8 publications

References 5 publications

Performance evaluation by computational fluid dynamics modelling of the heavy gas dispersion with a low Froude number in a built environment

Performance evaluation by computational fluid dynamics modelling of the heavy gas dispersion with a low Froude number in a built environment

Integral Multiphase Turbulence Compressible Jet Expansion Model for Accidental Releases from Pressurized Containments

A Review of Mathematical Models for the Atmospheric Dispersion of Heavy Gases. Part I. A Classification of Models

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