Measurements of Turbulent Dissipation Rate Using Large-Eddy Particle Image Velocimetry (LEPIV) Method

0444683 - ÚCHP 2016 SK eng C - Konferenční příspěvek (zahraniční konf.)
Vejražka, Jiří - Stanovský, Petr - Tihon, Jaroslav
Measurements of Turbulent Dissipation Rate Using Large-Eddy Particle Image Velocimetry (LEPIV) Method.
Proceedings of the 42nd International Conference of SSCHE. Bratislava: Slovak Society of Chemical Engineering, 2015 - (Markoš, J.), s. 81. ISBN 978-80-89475-14-8.
[International Conference of Slovak Society of Chemical Engineering /42./. Tatranské Matliare (SK), 25.05.2015-29.05.2015]
Grant CEP: GA MŠMT(CZ) LD13018; GA ČR GA15-15467S
Institucionální podpora: RVO:67985858
Klíčová slova: turbulencec * energy dissipation rate * particle-image velocimetry
Kód oboru RIV: CI - Průmyslová chemie a chemické inženýrství

Standard models for disintegration of bubbles or drops due to a turbulent flow characterize the flow using local dissipation rate of kinetic energy (epsilon). The practical measurements of epsilon are, however, difficult. In this presentation, we study epsilon in a flow generated by a set of coaxial nozzles. The velocity field is evaluated using Particle Image Velocimetry (PIV) technique. The measured velocity field is, however, not resolved till dissipation scales and the dissipation rate therefore cannot be evaluated directly. We therefore use Large-Eddy PIV method, described by Sheng, Meng and Fox (Chem Eng Sci 2000) to estimate turbulent stresses. The dissipation rate is then obtained from their product with shear velocities. To validate the approach, we integrate the dissipation rate in the setup to obtain total energy dissipation. This total is compared with the energy injected by the nozzles. Such a global validation reveals that the method sees about 50 % of the dissipated energy. This ratio remains the same for large range of injected energy, indicating that LEPIV method can be used for estimation of the dissipation rate, if properly corrected.
Trvalý link: http://hdl.handle.net/11104/0247198