Characteristics of coherent structures generated in channel flows during low Reynolds numbers mixed convection have been investigated in a square channel. The Gr/Re2 ranged between 21 and 206 which indicates that natural convection was dominant over forced convection. Two-dimensional velocity fields were measured using particle image velocimetry (PIV) technique in different planes to obtain a three-dimensional perspective of the flow field in the channel. The coherent structures were detected from the turbulent velocity fields using an algorithm based on the velocity gradient tensor second invariant (Q). The location of each detected coherent structure was recorded and its turbulent kinetic energy was computed. It was found that the strength of coherent structures increased with an increase in the bottom wall temperature. The results also indicate that the coherent structures present in the region away from the bottom heated wall were more energetic compared to the coherent structures present within the thermal boundary layer.
- Fluids Engineering Division
Characteristics of Coherent Structures in Channel Flows During Low Reynolds Number Mixed Convection Available to Purchase
Elatar, A, & Siddiqui, K. "Characteristics of Coherent Structures in Channel Flows During Low Reynolds Number Mixed Convection." Proceedings of the ASME 2014 4th Joint US-European Fluids Engineering Division Summer Meeting collocated with the ASME 2014 12th International Conference on Nanochannels, Microchannels, and Minichannels. Volume 1D, Symposia: Transport Phenomena in Mixing; Turbulent Flows; Urban Fluid Mechanics; Fluid Dynamic Behavior of Complex Particles; Analysis of Elementary Processes in Dispersed Multiphase Flows; Multiphase Flow With Heat/Mass Transfer in Process Technology; Fluid Mechanics of Aircraft and Rocket Emissions and Their Environmental Impacts; High Performance CFD Computation; Performance of Multiphase Flow Systems; Wind Energy; Uncertainty Quantification in Flow Measurements and Simulations. Chicago, Illinois, USA. August 3–7, 2014. V01DT27A014. ASME. https://doi.org/10.1115/FEDSM2014-21919
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