Modeling Heavy-Gas Dispersion in Air with Two-Layer Shallow Water Equations
| Autor: | Alexandre Chiapolino, Emmanuel Lapebie, Richard Saurel, Sébastien Courtiaud |
|---|---|
| Přispěvatelé: | Recherche Scientifique et Simulation Numérique [Roquevaire] (RS2N), GRAMAT (DAM/GRAMAT), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Wave propagation
Computation FOS: Physical sciences Context (language use) Physics - Classical Physics lcsh:Thermodynamics 01 natural sciences 010305 fluids & plasmas [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph] Momentum symbols.namesake Mathematics - Analysis of PDEs lcsh:QC310.15-319 0103 physical sciences FOS: Mathematics [MATH.MATH-AP]Mathematics [math]/Analysis of PDEs [math.AP] 0101 mathematics Dispersion (water waves) Shallow water equations drag effects Mathematics lcsh:QC120-168.85 Fluid Flow and Transfer Processes Mechanical Engineering [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment shallow water Classical Physics (physics.class-ph) gas dispersal Mechanics experiments Condensed Matter Physics Riemann solver 010101 applied mathematics Drag symbols [SPI.MECA.THER]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Thermics [physics.class-ph] two-layer lcsh:Descriptive and experimental mechanics hyperbolic systems Analysis of PDEs (math.AP) |
| Zdroj: | Fluids Fluids, MDPI, 2021 Fluids, 2021, 6 (1), pp.2. ⟨10.3390/fluids6010002⟩ Volume 6 Issue 1 Fluids, Vol 6, Iss 2, p 2 (2021) |
| ISSN: | 2311-5521 |
| DOI: | 10.3390/fluids6010002⟩ |
| Popis: | International audience; Computation of gas dispersal in urban places or hilly grounds requires a large amount of computer time when addressed with conventional multidimensional models. Those are usually based on two-phase flow or Navier-Stokes equations. Different classes of simplified models exist. Among them, two-layer shallow water models are interesting to address large-scale dispersion. Indeed, compared to conventional multidimensional approaches, 2D simulations are carried out to mimic 3D effects. The computational gain in CPU time is consequently expected to be tremendous. However, such models involve at least three fundamental difficulties. The first one is related to the lack of hyperbolicity of most existing formulations, yielding serious consequences regarding wave propagation. The second is related to the non-conservative terms in the momentum equations. Those terms account for interactions between fluid layers. Recently, these two difficulties have been addressed in Chiapolino and Saurel (2018) and an unconditional hyperbolic model has been proposed along with a Harten-Lax-van Leer (HLL) type Riemann solver dealing with the non-conservative terms. In the same reference, numerical experiments showed robustness and accuracy of the formulation. In the present paper, a third difficulty is addressed. It consists of the determination of appropriate drag effect formulation. Such effects also account for interactions between fluid layers and become of particular importance when dealing with heavy-gas dispersion. With this aim, the model is compared to laboratory experiments in the context of heavy gas dispersal in quiescent air. It is shown that the model accurately reproduces experimental results thanks to an appropriate drag force correlation. This function expresses drag effects between the heavy and light gas layers. It is determined thanks to various experimental configurations of dam-break test problems. |
| Databáze: | OpenAIRE |
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