Experimental Study of the Turbulent Field Behind a Perforated Vortex Generator
C. Habchi1, T. Lemenand2, D. Della Valle3,4, A. Al Shaer5, H. Peerhossaini6
1Notre Dame University, Louaize, Lebanon
2LUNAM University, IMIS ISTIA, Angers, France
3LUNAM University, LTN CNRS, UMR 6607, Nantes, France
4ONIRIS, Food Processing Dept., GEPEA, Nantes, France
5Lebanese International University LIU, Mechanical Engineering Dept, Beirut, Lebanon
6Universite Paris Diderot, Paris, France
Keywords: вихревой след, турбулентность, кинетическая энергия, энергетический спектр турбулентности, лазерные велосиметры, эффект Доплера, vorticity, turbulent kinetic energy, turbulence power spectra, laser Doppler velocimetry
Abstract
The influence of the wake vortex arising behind a perforated tab on the mixing process in heat exchangers and chemical reactors is analyzed. The preliminary step of this study, i.e., investigation of the turbulent field generated by a single perforated tab, is presented here. For this aim, laser Doppler velocimetry measurements are conducted downstream from a perforated trapezoidal vortex generator placed in a wind tunnel. It is shown that two shear layers are generated by the tab. The first shear layer is located at the upper edge of the tab, and the other is ejected from the perforation edges. These shear layers are characterized by high turbulent kinetic energy levels, which are profitable for meso-mixing enhancement. Finally, a spectral study shows that the turbulent macro-scale is nearly the same for typical locations in the shear layers shed from the tab and perforation edges.
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