Dynamic plume model

Dynamic Plume Model for the Prediction of Atmospheric Effects Associated with Cooling Tower Operation... 

The puff model can be used to describe a plume a plume is simply the release of continuous puffs. However, if steady-state plume information is all that is required, the plume model is recommended because it is easier to use. For studies involving dynamic plumes (for instance, the effect on a plume of a change in wind direction), the puff model must be used. 

Deen et al [30] used the lift force in addition to the steady drag- and added mass forces in their dynamic 3D-model to obtain the transversal spreading of the bubble plume which is observed in experiments. A prescribed zero void wall boundary was used forcing the gas to migrate away from the wall. The continuous phase turbulence was incorporated in two different ways, using... 

Two models for analyte ion formation have been proposed. The older model -which had not had a well-defined name before 2013 and is now proclaimed as Coupled Physical and Chemical Dynamics (CPCD) model - assumes neutral analyte molecules in the expanding plume - regardless of whether the analytes were incorporated in the matrix crystals as neutral species or were quantitatively neutralized by their counterions upon cluster dissociation in the case of precharged incorporated analyte molecules. Subsequent to photoionization of the matrix (Eqs 1.3 and 1.4) and secondary intermolecular matrix reactions leading to the generation of protonated as well as deprotonated matrix ions (Eqs 1.5 and 1.6)... 

The presence of a lithosphere with a thickness up to 100 km above the plume head obscures observations that could be made in terms of heat flow, gravity field or seismic structure. Establishing the temperature and flow fields beneath a hotspot thus becomes a difficult exercise. Several key parameters (Fig. 2) are poorly constrained and mostly result from theoretical fluid dynamics model, which underlines their large uncertainty. The temperature anomaly within the hotspot region is generally estimated to be approximately 200 100°C with large uncertainties (Shilling 1991 Sleep 1990). These temperature anomalies will induce smaller densities in the plume and the flux of the density anomalies is called buoyancy flux as defined in (Sleep 1990) ... 

Hasemi, Y. and Tokunaga, T., In modeling of turbulent diffusion flames and fire plumes for the analysis of fire growth, 21st National Heat Transfer Conference, Fire Dynamics and Heat Transfer, Seattle, WA, 1983, pp. 37 15. 

The difference between RANS and LES is depicted in Figure 20.1, which shows the temperature fields of a pool fire flame. While the RANS result shows smooth variations and looks like a laminar flame, the LES result clearly illustrates the large-scale eddies. Both results are the correct solutions of the corresponding equations. However, the time accuracy of LES is also essential for the quantitative accuracy of the buoyancy-driven flows. As Rehm and Baum have shown [10], the dynamic motions or eddies are responsible for most of the air entrainment into the fire plumes. Because these motions cannot be captured by RANS, LES is usually better suited for fire-driven flow. LES typically requires a finer spatial resolution than RANS. Examples of RANS-based fire CFD models are JASMINE, KAMELEON [11], SMARTFIRE [12], SOFIE [13], ISIS [14], and ISIS-3D [15]. Examples of LES models are the FDS [4,5] and SMAFS [16], developed at Lund University. Fire simulations using LES have also been performed by Cheung et al. [17] and Gao et al. [18],... 

Siegel, H., Gerth, M., Mutzke, A., 1999a. Dynamics of the Oder river plume in the southern Baltic Sea Netherlond, p. 514. satellite data and numerical modelling. Continental Shelf Research, 19,1143-1159. 

Embedded in the circulation model, it provides a coupled physical-biogeochemical model of the Baltic Sea ecosystem as an example application. Several applications of the model system are discussed, covering process studies, such as currents in the western Baltic, river plumes, and sediment transport, but also long-term simulations of the ecosystem dynamics. 

Horizontal and vertical advection of heat and dissolved substances implies numerical mixing, which is the less important the smaller the grid cell volume is. Hence, abetter model resolution conserves the signamre of inflowing saltwater, which is essential for the simulation of bottom water renewal in the deep basins of the Baltic Sea. Also for the representation of frontal or river plume dynamics, a sufficient model resolution is required. 

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