Lid-driven cavity flow-induced dynamics of a neutrally buoyant solid: Effect of Reynolds number, flexibility, and size

• Published in: Physics of fluids (1994) Vol. 34; no. 7
• Main Authors: Prasad, Vinay, Sharma, Atul, Kulkarni, Salil S.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 01.07.2022
• Subjects: Cavity flow; Centroids; Deformation; Flexibility; Flow velocity; Fluid dynamics; Fluid flow; Formability; Newtonian fluids; Orbits; Reynolds number; Shear modulus
• ISSN: 1070-6631; 1089-7666
• DOI: 10.1063/5.0096238

The present work is on Fluid flexible–Solid Interaction (FfSI), involving a recirculating flow-induced motion of a neutrally buoyant and deformable circular solid. For a Newtonian fluid flow and neo-Hookean flexible-solid deformation, a single FfSI solver—based on fully Eulerian and monolithic approaches—is used. The effect of Reynolds Number Re (20–500), volume fraction Φ (1%–12%) of the solid, and its non-dimensional shear modulus G * ( 0.02 – 1) on transient/periodic flow-induced solid-motion and the associated FfSI analysis is presented. The solid undergoes a transient spiraling motion before attaining a periodic orbit-based limit cycle. The flow also attains the periodic state after the initial transients. Time-averaged flow velocity-magnitude ⟨ v *⟩ surrounding the limit cycle increases with increasing Re, increasing G * , and decreasing Φ. Equivalent radius r e q * of the limit cycle and time-averaged velocity-magnitude ⟨ v c *⟩ of the centroid of the solid increase with increasing Re and decrease with decreasing G * (or increasing flexibility) and increasing volume fraction Φ (or size) of the solid. Also, frequency f * of the limit cycle decreases with increasing Re and remains almost constant with G * and Φ. With increasing Φ, the limit cycle undergoes a transition from the single loop to double loop beyond a critical volume fraction Φ c = 2 %. A critical Reynolds number Rec, below which the periodic limit cycle collapses to a point, decreases with decreasing Φ. Our findings will help in the prediction and control of the motion of the solid in a bounded fluid flow involving solids of varying flexibility, which is relevant to a wide range of industrial and biological applications.