Fiber suspension investigation in a backward-facing step by PIV

24th A.I.VE.LA. Annual Meeting

Capone, A.^1 ; Romano, G.P.^2 ; Soldati, A.^3

CNR-INSEAN, Via di Vallerano 139, Rome, Italy^1

Dipartimento Ingegneria Meccanica e Aeronautica, Università la Sapienza, Via Eudossiana 18, Rome, Italy^2

Dipartimento Politecnico, Università di Udine, Via delle Scienze 208, Udine, Italy^3

关键词: Backward facing step;    Backward-facing step flows;    High spatial resolution;    Local fiber orientation;    Particle image velocimetries;    Preferential concentration;    Preferential orientation;    Turbulence enhancements;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/882/1/012018/pdf
DOI  :  10.1088/1742-6596/882/1/012018

来源: IOP

【 摘 要 】

A dilute suspension (volume fraction 0.05%) of rod-like particles in a turbulent backward-facing step flow at Reynolds number ReH=14900, is investigated by means of Particle Image Velocimetry. Two-way interactions between fluid and dispersed phase are analyzed by exploiting the high spatial resolution of the acquisitions. Mutual interactions between phases can be investigated by considering flow turbulence modulations and phenomena related to preferential concentration and orientation of fibers. Slight turbulence enhancement is reported in the laden flow and concentration data show a moderate tendency of fibers to accumulate at the channel centreline. Orientation data display a strong preferential orientation of fibers. Local fiber orientation is correlated to the direction of maximum shear showing a high level of correlation also in the flow regions featuring strong gradients.