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Free keywords:
Reynolds stress modeling; Turbulence effects; Energy transfer; Statistical properties; Lagrangian mechanics
Abstract:
Turbulence modulation by inertial-range-size, neutrally buoyant particles is investigated experimentally in a von K?rm?n flow. Increasing the particle volume fraction �v, maintaining constant impellers Reynolds number attenuates the fluid turbulence. The inertial-range energy transfer rate decreases as ? �2/3 v , suggesting that only particles located on a surface affect the flow. Small-scale turbulent properties, such as structure functions or acceleration distribution, are unchanged. Finally, measurements hint at the existence of a transition between two different regimes occurring when the average distance between large particles is of the order of the thickness of their boundary layers.
