High-Resolution Numerical Simulations of a Large-Scale Helium Plume Using Adaptive Mesh Refinement

Nicholas T. Wimer; Marcus S. Day; Caelan Lapointe; Amanda S. Makowiecki; Jeffrey F. Glusman; John W. Daily; Gregory B. Rieker; Peter E. Hamlington

arXiv · 1901.10554

High-Resolution Numerical Simulations of a Large-Scale Helium Plume Using Adaptive Mesh Refinement

Nicholas T. Wimer·Marcus S. Day·Caelan Lapointe·Amanda S. Makowiecki·Jeffrey F. Glusman·John W. Daily·Gregory B. Rieker·Peter E. Hamlington

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Abstract

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~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~mm and 1.95~mm, below which the mean statistics and frequency content of the plume are altered by the development of a Rayleigh-Taylor instability near the centerline in close proximity to the base of the plume. This shift corresponds to a plume "puffing" frequency that is slightly higher than would be predicted using empirical relationships developed for buoyant jets. Ultimately, the high-fidelity simulations performed here are intended as a new validation dataset for the development of subgrid-scale models used in large eddy simulations of real-world buoyancy-driven flows.

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BibTeX RIS

Nicholas T. Wimer, Marcus S. Day, Caelan Lapointe, Amanda S. Makowiecki, Jeffrey F. Glusman, John W. Daily, Gregory B. Rieker, Peter E. Hamlington. 2019-01-11. High-Resolution Numerical Simulations of a Large-Scale Helium Plume Using Adaptive Mesh Refinement. https://arxiv.org/abs/1901.10554

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