Mixing in modulated turbulence. Analytical results
Autor: | Wouter J. T. Bos, Robert Rubinstein |
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Přispěvatelé: | Laboratoire de Mecanique des Fluides et d'Acoustique (LMFA), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Newport News |
Jazyk: | angličtina |
Rok vydání: | 2017 |
Předmět: |
Physics
General Computer Science K-epsilon turbulence model Turbulence Energy transfer Scalar (mathematics) Mixing rate Fluid Dynamics (physics.flu-dyn) General Engineering Turbulence modeling FOS: Physical sciences Physics - Fluid Dynamics Mechanics K-omega turbulence model modulated turbulence 01 natural sciences isotropic turbulence 010305 fluids & plasmas Amplitude modulation Classical mechanics 0103 physical sciences Vector field [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph] 010306 general physics passive scalar |
Zdroj: | Computers and Fluids Computers and Fluids, Elsevier, 2017, ⟨10.1016/j.compfluid.2016.10.024⟩ |
ISSN: | 0045-7930 |
DOI: | 10.1016/j.compfluid.2016.10.024⟩ |
Popis: | Recent numerical results show that if a scalar is mixed by periodically forced turbulence, the average mixing rate is directly affected for forcing frequencies small compared to the integral turbulence frequency. We elucidate this by an analytical study using simple turbulence models for spectral transfer. Adding a large amplitude modulation to the forcing of the velocity field enhances the energy transfer and simultaneously diminishes the scalar transfer. Adding a modulation to a random stirring protocol will thus negatively influence the mixing rate. We further derive the asymptotic behaviour of the response of the passive scalar quantities in the same flow for low and high forcing frequencies. Comment: in Computers & Fluids, 2016 |
Databáze: | OpenAIRE |
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