Skip to Main content Skip to Navigation
Preprints, Working Papers, ...

Experimental and numerical shadowgraph in turbulent Rayleigh-Bénard convection with a rough boundary: investigation of plumes

Abstract : We show that, in the case of turbulent Rayleigh-Bénard convection, shadowgraph can be used to have quantitative results on the plumes statistics and their velocity. For this purpose, we compare the experimental shadowgraph of a Rayleigh-Bénard cell with the synthetic shadowgraph obtained by calculating the integrated 2D Laplacian of the temperature field from a numerical simulation very similar to the experiment. We use image processing tools to enhance the quality of the shadowgraph image, and obtain quantitative statistics for the thermal plumes, such as plume density, and plume velocity distribution. To highlight the efficiency of this new process of plume counting, we use, both in the experiment and in the numerical simulation, a turbulent Rayleigh-Bénard convection cell with a rough bottom surface, and a smooth top surface, where the statistics of the plumes can be influenced (or not) by the roughness. In addition, the distribution of velocity obtained from processing the synthetic shadowgraph images of the DNS or the experimental shadowgraph images, are compared to the velocity fluid at mid plane of the DNS or PIV measurement in the experiment, respectively. It will be shown that the mean velocity profile measured using the advection of the plumes is different from the average eulerian velocity profile.
Complete list of metadatas

Cited literature [95 references]  Display  Hide  Download

https://hal.archives-ouvertes.fr/hal-02329929
Contributor : Julien Salort <>
Submitted on : Monday, April 6, 2020 - 1:58:43 PM
Last modification on : Wednesday, April 8, 2020 - 1:44:30 AM

File

JFM_Ombro_HAL_v3.pdf
Files produced by the author(s)

Identifiers

  • HAL Id : hal-02329929, version 3

Citation

Bérengère Podvin, Mebarek Belkadi, Laura Guislain, Anne Sergent, Berengere Podvin, et al.. Experimental and numerical shadowgraph in turbulent Rayleigh-Bénard convection with a rough boundary: investigation of plumes. 2020. ⟨hal-02329929v3⟩

Share

Metrics

Record views

77

Files downloads

50