Visualization of Stratified Flows around a Vertical Plate: Laboratory Experiment and Numerical Simulation

Visualization of Stratified Flows around a Vertical Plate: Laboratory Experiment and Numerical Simulation

Yuli Chashechkin Yaroslav Zagumennyi

Institute for Problems in Mechanics, Russian Academy of Sciences, Moscow, Russia

Institute of Hydromechanics, National Academy of Sciences of Ukraine, Kiev, Ukraine

Available online: 
| Citation

© 2020 IIETA. This article is published by IIETA and is licensed under the CC BY 4.0 license (



On the basis of the fundamental system, which includes equations of continuity, momentum, and substance transfer with a linearized equation of state, methods of experimental and numerical study are developed for visualizing the flow perturbation fields generated by uniform horizontal movement of a vertical plate in a stratified medium. The stratified flows were visualized in the laboratory tank by the high-sensitive and high-resolution Schlieren instrument IAB-458 at the stand ‘Laboratory Mobile Tank’ of the Unique Research Facility ‘HPC IPMech RAS’ and numerically calculated within the frame of the open source CFD utility OpenFOAM using computing resources of cluster systems and supercomputers. Both the computation results and the laboratory visualization data show that a vertical plate uniformly moving in a stratified fluid generates flow patterns which contain complex systems of internal waves, including upstream, attached and short ones, and thin interfaces, such as ligaments, formed due to the combined influence of the stratification and dissipation effects. Increase in the velocity of the plate movement leads to an essential restructuring of the wake flow past the plate, where typical vortex elements, such as vortex dipoles and ‘vortex bubbles’, are formed in the divergence zones of the phase surfaces of internal waves. All the flow structural components evolve and actively interact with each other and with the free stream. The observation and calculation results are in a good qualitative and quantitative agreement with each other.


ligaments, OpenFOAM, stratified flow, vertical plate, vortices, visualization, waves


[1] Schlichting, H. &Gersten, K., Boundary Layer Theory, Springer-Verlag: Berlin, 2017.

[2] Turner, J.C., Buoyancy Effects in Fluids, Cambridge University Press, 1973.

[3] Chashechkin, Yu.D. & Mitkin, V.V., Experimental study of a fine structure of 2D wakesand mixing past an obstacle in a continuously stratified fluid. Dynamics of Atmosphereand Oceans, 34, pp. 165–187, 2001.

[4] Chashechkin, Yu.D. & Mitkin, V.V., A visual study on flow pattern around the stripmoving uniformly in a continuously stratified fluid. Journal of Visualization, 7(2),pp. 127–134, 2004.

[5] Prokhorov, V.E. & Chashechkin, Yu.D., Visualization and acoustic sounding of the finestructure of a stratified flow behind a vertical plate. Fluid Dynamics, 48(6), pp. 722–733,2013.

[6] Houcine, H., Chashechkin, Yu.D., Fraunie, Ph., Fernando, H., Gharbi, A. & Lili, T.,Numerical modeling of the generation of internal waves by uniform stratified flowover a thin vertical barrier. International Journal for Numerical Methods in Fluids, 68,pp. 451–466, 2012.

[7] Sutherland, B.R. & Linden, P.F., Internal wave excitation from stratified flow over a thinbarrier. Journal of Fluid Mechanics, 377, pp. 223–252, 1998.

[8] Kiya, M. & Matsumura, M., Incoherent turbulence structure in the near wake of anormalplate. Journal of Fluid Mechanics, 190, pp. 343–356, 1988.

[9] Castro, P., Cliffe, K.A. & Norgett, M.J., Numerical predictions of the laminar flowover a normal flat plate. International Journal for Numerical Methods in Fluids, 2,pp. 61–88, 1982.

[10] Chernyshenko, S.I. & Castro, I.P., High-Reynolds-number weakly stratified flow pastan obstacle. Journal of Fluid Mechanics, 317, pp. 155–178, 1996.

[11] Castro, I.P., Wake characteristics of two-dimensional perforated plates normal to anair-stream. Journal of Fluid Mechanics, 46, pp. 599–609, 1971.

[12] Basnet, K. & Constantinescu, G., The structure of turbulent flow around vertical platescontaining holes and attached to a channel bed. Physics of Fluids, 29(11), 115101,2017.

[13] Basnet, K. & Constantinescu, G., Effect of a bottom gap on the mean flow and turbulencestructure past vertical solid and porous plates situated in the vicinity of a horizontalchannel bed. Physical Review Fluids, 4, 044604, 2019.

[14] Landau, L.D. & Lifshits, E.M., Theoretical Physics. Hydromechanics. Pergamon Press,1987.

[15] Zagumennyi, Ia.V. & Chashechkin, Yu.D., Diffusion induced flow on a strip: Theoretical,numerical and laboratory modelling. Procedia IUTAM, 8, pp. 256–266, 2013.

[16] Chashechkin, Yu.D. & Zagumennyi, Ia.V., Formation of waves, vortices and ligamentsin 2D stratified flows around obstacles. Physica Scripta, 94(5), 054003, 2019.

[17] Hydrophysical Complex for Modeling Hydrodynamic Processes in the Environment andTheir Impact on Underwater Technical Objects, as well as the Distribution of Impuritiesin the Ocean and Atmosphere, IPMech RAS, Online,

[18] Maksutov, D.D., Shadow methods of analyzing optical systems. Seriya ProblemyNoveishei Fiziki, 23, GTI, 1934.

[19] Chashechkin, Yu.D., Schlieren visualization of a stratified flow around a cylinder.Journalof Visualization, 1(4), pp. 345–354, 1999.

[20] Jasak, H., OpenFOAM: Open source CFD in research and industry. InternationalJournalof Naval Architecture and Ocean Engineering, 1(2), pp. 89–94, 2009.

[21] Kistovich, Yu.V. & Chashechkin, Yu.D., A new mechanism of the non-linear generationof internal waves. Doklady Physics, 47(2), pp. 163–167, 2002.