Correlations on weakly time-dependent transcritical white-hole flows
| Autor: | Johan Fourdrinoy, Scott Robertson, Nicolas James, Alessandro Fabbri, Germain Rousseaux |
|---|---|
| Přispěvatelé: | Institut Pprime (PPRIME), Université de Poitiers-ENSMA-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire Charles Fabry / Gaz Quantiques, Laboratoire Charles Fabry (LCF), Institut d'Optique Graduate School (IOGS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Institut d'Optique Graduate School (IOGS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Mathématiques et Applications (LMA-Poitiers), Université de Poitiers-Centre National de la Recherche Scientifique (CNRS), Dep. de Fisica Teorica and IFIC, Universitat de Valencia-CSIC, ACI Pprime, Project OFHYS of the CNRS 80 Pprime initiative, PROMETEO/2020/079 (Generalitat Valenciana), European Commission, Ministerio de Ciencia e Innovación (España), Generalitat Valenciana, Agencia Estatal de Investigación (España) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
[PHYS.PHYS.PHYS-FLU-DYN]Physics [physics]/Physics [physics]/Fluid Dynamics [physics.flu-dyn]
Fluid Dynamics (physics.flu-dyn) [PHYS.GRQC]Physics [physics]/General Relativity and Quantum Cosmology [gr-qc] FOS: Physical sciences Physics::Accelerator Physics General Relativity and Quantum Cosmology (gr-qc) Physics - Fluid Dynamics General Relativity and Quantum Cosmology |
| Popis: | We report observations made on a run of transcritical flows over an obstacle in a narrow channel. Downstream from the obstacle, the flows decelerate from supercritical to subcritical, typically with an undulation on the subcritical side (known in hydrodynamics as an undular hydraulic jump). In the Analogue Gravity context, this transition corresponds to a white-hole horizon. Free-surface deformations are analyzed, mainly via the two-point correlation function which shows the presence of a checkerboard pattern in the vicinity of the undulation. In nongated flows where the white-hole horizon occurs far downstream from the obstacle, this checkerboard pattern is shown to be due to low-frequency fluctuations associated with slow longitudinal movement of the undulation. It can thus be considered as an artifact due to a time-varying background. In gated flows, however, the undulation is typically "attached"to the obstacle, and the fluctuations associated with its movement are strongly suppressed. In this case, the observed correlation pattern is likely due to a stochastic ensemble of surface waves, scattering on a background that is essentially stationary. This work pertains to the French government program “Investissements d’Avenir” (EUR INTREE, reference ANR-18-EURE- 0010, and LABEX INTERACTIFS, reference ANR-11- LABX-0017-01). It benefited from the support of the project OFHYS of the CNRS 80 Pprime initiative in and from an internal funding scheme ACI Pprime. A. F. acknowledges partial financial support by the Spanish grants from Ministerio de Ciencia e Innovación Grant No. FIS2017-84440-C2-1-P funded by MCIN/AEI/ 10.13039/501100011033 “ERDF A way of making Europe,” Grant No. PID2020–116567 GB-C21 funded by MCIN/AEI/10.13039/501100011033, and Project No. PROMETEO/2020/079 (Generalitat Valenciana). S. R. and A. F. acknowledge support from the French National Research Agency through Grant No. ANR-20-CE47-0001 associated with the project COSQUA (Cosmology and Quantum Simulation). The authors thank Professor Eric Lamballais for the lending of the water channel. |
| Databáze: | OpenAIRE |
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