Numerical simulations of buoyancy-driven flows using adaptive mesh refinement: structure and dynamics of a large-scale helium plume
| العنوان: | Numerical simulations of buoyancy-driven flows using adaptive mesh refinement: structure and dynamics of a large-scale helium plume |
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| المؤلفون: | Nicholas T. Wimer, Marcus S. Day, Amanda S. Makowiecki, Peter E. Hamlington, Caelan Lapointe, Michael Meehan, Gregory B. Rieker, John W. Daily, Jeffrey F. Glusman |
| المصدر: | Theoretical and Computational Fluid Dynamics. 35:61-91 |
| بيانات النشر: | Springer Science and Business Media LLC, 2020. |
| سنة النشر: | 2020 |
| مصطلحات موضوعية: | Fluid Flow and Transfer Processes, Physics, Buoyancy, Adaptive mesh refinement, Flow (psychology), General Engineering, Computational Mechanics, chemistry.chemical_element, Mechanics, engineering.material, Vorticity, Condensed Matter Physics, 01 natural sciences, Instability, 010305 fluids & plasmas, Plume, Physics::Fluid Dynamics, chemistry, 0103 physical sciences, engineering, Rayleigh–Taylor instability, 010306 general physics, Helium |
| الوصف: | The physical characteristics and evolution of a large-scale helium plume are examined through a series of numerical simulations with increasing physical resolution using adaptive mesh refinement (AMR). The five simulations each model a 1-m-diameter circular helium plume exiting into a $$(4~\hbox {m})^3$$ domain and differ solely with respect to the smallest scales resolved using the AMR, spanning resolutions from 15.6 mm down to 0.976 mm. As the physical resolution becomes finer, the helium–air shear layer and subsequent Kelvin–Helmholtz instability are better resolved, leading to a shift in the observed plume structure and dynamics. In particular, a critical resolution is found between 3.91 and 1.95 mm, below which the mean statistics and frequency content of the plume are altered by the development of a Rayleigh–Taylor (RT) instability near the centerline in close proximity to the plume base. Comparisons are made with prior experimental and computational results, revealing that the presence of the RT instability leads to reduced centerline axial velocities and higher puffing frequencies than when the instability is absent. An analysis of velocity and scalar gradient quantities, and the dynamics of the vorticity in particular, show that gravitational torque associated with the RT instability is responsible for substantial vorticity production in the flow. The grid-converged simulations performed here indicate that very high spatial resolutions are required to accurately capture the near-field structure and dynamics of large-scale plumes, particularly with respect to the development of fundamental flow instabilities. |
| تدمد: | 1432-2250 0935-4964 |
| DOI: | 10.1007/s00162-020-00548-6 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::56161aa1a17b0d9957a0ca1cef8a0718 https://doi.org/10.1007/s00162-020-00548-6 |
| Rights: | CLOSED |
| رقم الانضمام: | edsair.doi...........56161aa1a17b0d9957a0ca1cef8a0718 |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 14322250 09354964 |
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| DOI: | 10.1007/s00162-020-00548-6 |