Is the Volume-of-Fluid Method Coupled with a Sub-Grid Bubble Equation Efficient for Simulating Local and Continuum Aeration?
| Autor: | Lourenço Mendes, Maria Teresa Viseu, Javier L. Lara |
|---|---|
| Přispěvatelé: | Universidad de Cantabria |
| Rok vydání: | 2021 |
| Předmět: |
Hydraulic structures
Entrainment (hydrodynamics) Bubble hydraulic structure Geography Planning and Development Flow (psychology) 0207 environmental engineering 02 engineering and technology Free-surface aeration Aquatic Science 01 natural sciences Biochemistry 010305 fluids & plasmas Physics::Fluid Dynamics 0103 physical sciences Volume of fluid method 020701 environmental engineering TD201-500 Water Science and Technology Jet (fluid) Water supply for domestic and industrial purposes Hydraulic engineering Mechanics Boundary layer Turbulence kinetic energy Environmental science Air entrainment TC1-978 Sub-grid bubble equation Local aeration Volume-of-fluid |
| Zdroj: | Water 2021, 13(11), 1535 UCrea Repositorio Abierto de la Universidad de Cantabria Universidad de Cantabria (UC) Water Volume 13 Issue 11 Water, Vol 13, Iss 1535, p 1535 (2021) |
| ISSN: | 2073-4441 |
| DOI: | 10.3390/w13111535 |
| Popis: | Air entrainment is common in free surface flows in large hydraulic structures (e.g., spillways, chutes, energy dissipation structures) and must be considered to assure an effective and safe operation. Due to the large size of the prototype structures, it is infeasible to model individual air bubbles. Therefore, using the OpenFOAM toolbox, an efficient simulation model for aerated flows is developed for engineering purposes. The Reynolds-averaged Navier–Stokes equations and the volume-of-fluid method are coupled with a sub-grid bubble population model that simulates entrainment and transport. A comprehensive assessment of the effectiveness, computational cost, and reliability is performed. Local and continuum bubble entrainment are evaluated in two distinct flows: an impinging jet and along a spillway chute. Aeration is induced, respectively, by a shear flow and by the thickening of the turbulent boundary layer. Moreover, a detailed sensitivity analysis of the model’s parameters is conducted. Calibration and validation are performed against experimental and prototype data. Among the analyzed entrainment formulations, the one depending exclusively on the turbulent kinetic energy is the only applicable to different flow types. Good accuracy is found, meeting engineering standards, and the additional computation cost is marginal. Results depend primarily on the volume-of-fluid method ability to reproduce the interface. Calibration is straightforward in self-aeration but more difficult for local aeration. |
| Databáze: | OpenAIRE |
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