Unsteady flow of shear-thickening fluids around an impulsively moving circular cylinder

2019 ◽  
Vol 272 ◽  
pp. 104163 ◽  
Author(s):  
Junseong Lee ◽  
Junkyu Kim ◽  
Jiseop Lim ◽  
Yeji Yun ◽  
Youngho Kim ◽  
...  
Keyword(s):  
Circular Cylinder ◽  
Unsteady Flow ◽  
Shear Thickening ◽  
Shear Thickening Fluids

First instability of the flow of shear-thinning and shear-thickening fluids past a circular cylinder

2012 ◽  
Vol 701 ◽  
pp. 201-227 ◽  
Author(s):  
Iman Lashgari ◽  
Jan O. Pralits ◽  
Flavio Giannetti ◽  
Luca Brandt
Keyword(s):  
Circular Cylinder ◽  
Shear Thickening ◽  
Shear Thinning ◽  
Base Flow ◽  
Rheological Parameters ◽  
Recirculation Bubble ◽  
The Core ◽  
Shear Dependent Viscosity ◽  
Shear Thickening Fluids ◽  
Dependent Viscosity

AbstractThe first bifurcation and the instability mechanisms of shear-thinning and shear-thickening fluids flowing past a circular cylinder are studied using linear theory and numerical simulations. Structural sensitivity analysis based on the idea of a ‘wavemaker’ is performed to identify the core of the instability. The shear-dependent viscosity is modelled by the Carreau model where the rheological parameters, i.e. the power-index and the material time constant, are chosen in the range $0. 4\leq n\leq 1. 75$ and $0. 1\leq \lambda \leq 100$. We show how shear-thinning/shear-thickening effects destabilize/stabilize the flow dramatically when scaling the problem with the reference zero-shear-rate viscosity. These variations are explained by modifications of the steady base flow due to the shear-dependent viscosity; the instability mechanisms are only slightly changed. The characteristics of the base flow, drag coefficient and size of recirculation bubble are presented to assess shear-thinning effects. We demonstrate that at critical conditions the local Reynolds number in the core of the instability is around 50 as for Newtonian fluids. The perturbation kinetic energy budget is also considered to examine the physical mechanism of the instability.

Research and Applications of Shear Thickening Fluids

2011 ◽  
Vol 4 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Jie Ding ◽  
Weihua Li ◽  
Shirley Z. Shen
Keyword(s):  
Shear Thickening ◽  
Shear Thickening Fluids

Dynamic compressive response of 3D GFRP composites with shear thickening fluid (STF) matrix as cushioning materials

2021 ◽  
pp. 002199832098424
Author(s):  
Mohsen Jeddi ◽  
Mojtaba Yazdani
Keyword(s):  
Shear Thickening ◽  
Low Velocity Impact ◽  
Gfrp Composites ◽  
High Concentration ◽  
Low Velocity ◽  
Shear Thickening Fluid ◽  
Compressive Response ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Shear Thickening Fluids

Whereas most previous studies have focused on improving the penetration resistance of Shear Thickening Fluids (STFs) treated composites, in this study, the dynamic compressive response of single and multi-ply 3 D E-Glass Fiber Reinforced Polymer (GFRP) composites with the STF matrix was investigated by using a drop-weight low-velocity impact test. The experimental results revealed the STF improved the compressive and cushioning performance of the composites such that with increasing its concentration, further improvement was observed. The five-ply composite containing the STF of 30 wt% silica nanoparticles and 1 wt% carbon nanotubes (CNTs) reduced the applied peak force by 56% and 26% compared to a steel plate and five-ply neat samples, respectively. A series of repeated impacts was performed, and it was found that the performance of high-concentration composites is further decreased under this type of loading.

scholarly journals Pre- and post-transition behavior of shear-thickening fluids in oscillating shear

2007 ◽  
Vol 46 (8) ◽  
pp. 1099-1108 ◽  
Author(s):  
Christian Fischer ◽  
Christopher J. G. Plummer ◽  
Véronique Michaud ◽  
Pierre-Etienne Bourban ◽  
Jan-Anders E. Månson
Keyword(s):  
Shear Thickening ◽  
Transition Behavior ◽  
Shear Thickening Fluids

scholarly journals Vortex motion in the early stages of unsteady flow around a circular cylinder

Sadhana ◽  
1984 ◽  
Vol 7 (2) ◽  
pp. 119-135 ◽  
Author(s):  
Guo-Can Ling ◽  
Xie-Yuan Yin
Keyword(s):  
Circular Cylinder ◽  
Unsteady Flow ◽  
Vortex Motion ◽  
Early Stages

Stability of Shear-Thickening Liquids Between Rotating Cylinders

2010 ◽  
Author(s):  
Nariman Ashrafi ◽  
Habib Karimi Haghighi
Keyword(s):  
Couette Flow ◽  
Dynamical Behavior ◽  
Shear Thickening ◽  
Shear Thinning ◽  
Taylor Vortex ◽  
Shear Dependent Viscosity ◽  
Shear Thinning Fluids ◽  
Shear Thickening Fluids ◽  
The Stability ◽  
Dependent Viscosity

The effects of nonlinearities on the stability are explored for shear thickening fluids in the narrow-gap limit of the Taylor-Couette flow. It is assumed that shear-thickening fluids behave exactly as opposite of shear thinning ones. A dynamical system is obtained from the conservation of mass and momentum equations which include nonlinear terms in velocity components due to the shear-dependent viscosity. It is found that the critical Taylor number, corresponding to the loss of stability of Couette flow becomes higher as the shear-thickening effects increases. Similar to the shear thinning case, the Taylor vortex structure emerges in the shear thickening flow, however they quickly disappear thus bringing the flow back to the purely azimuthal flow. Naturally, one expects shear thickening fluids to result in inverse dynamical behavior of shear thinning fluids. This study proves that this is not the case for every point on the bifurcation diagram.

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