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Main Authors: Narula, Hridey, Pandey, Vikash, Mitra, Dhrubaditya, Perlekar, Prasad
Format: Preprint
Published: 2025
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Online Access:https://arxiv.org/abs/2506.07693
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author Narula, Hridey
Pandey, Vikash
Mitra, Dhrubaditya
Perlekar, Prasad
author_facet Narula, Hridey
Pandey, Vikash
Mitra, Dhrubaditya
Perlekar, Prasad
contents Buoyancy-driven bubbly flows naturally have spatially-dependent density fields, which allow for multiple definitions of the scale-dependent (or filtered) energy. A priori, it is not obvious which of these provide the most physically apt scale-by-scale budget. In the present study, we compare two such definitions, based on (a) filtered momentum and filtered velocity (Pandey et al. 2020), and (b) Favre filtered energy (Aluie 2013; Pandey et al. 2023). We also derive a Kármán-Howarth-Monin (KHM) relation using the momentum-velocity correlation function and contrast it with the scale-by-scale energy budget obtained in (a). We find that for the volume fraction and Atwood number explored, irrespective of the definition, energy transfers due to the advective nonlinearity and surface tension are identical. However, discrepancies arise for the buoyancy and pressure contributions. We show that the Favre filtered definition is the more appropriate choice, within which buoyancy injects energy, pressure transfers energy to large scales, and both advective nonlinearity and surface tension transfer energy downscales where it is dissipated by viscosity.
format Preprint
id arxiv_https___arxiv_org_abs_2506_07693
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Scale-by-scale energy transfers in bubbly flows
Narula, Hridey
Pandey, Vikash
Mitra, Dhrubaditya
Perlekar, Prasad
Fluid Dynamics
Buoyancy-driven bubbly flows naturally have spatially-dependent density fields, which allow for multiple definitions of the scale-dependent (or filtered) energy. A priori, it is not obvious which of these provide the most physically apt scale-by-scale budget. In the present study, we compare two such definitions, based on (a) filtered momentum and filtered velocity (Pandey et al. 2020), and (b) Favre filtered energy (Aluie 2013; Pandey et al. 2023). We also derive a Kármán-Howarth-Monin (KHM) relation using the momentum-velocity correlation function and contrast it with the scale-by-scale energy budget obtained in (a). We find that for the volume fraction and Atwood number explored, irrespective of the definition, energy transfers due to the advective nonlinearity and surface tension are identical. However, discrepancies arise for the buoyancy and pressure contributions. We show that the Favre filtered definition is the more appropriate choice, within which buoyancy injects energy, pressure transfers energy to large scales, and both advective nonlinearity and surface tension transfer energy downscales where it is dissipated by viscosity.
title Scale-by-scale energy transfers in bubbly flows
topic Fluid Dynamics
url https://arxiv.org/abs/2506.07693