Fiber–fiber interaction in concentrated suspensions: Disperse fibers

1999 ◽  
Vol 43 (4) ◽  
pp. 991-1004 ◽  
Author(s):  
Colin Servais ◽  
Jan-Anders E. Månson ◽  
Staffan Toll
1999 ◽  
Vol 43 (4) ◽  
pp. 1005-1018 ◽  
Author(s):  
Colin Servais ◽  
André Luciani ◽  
Jan-Anders E. Månson

Entropy ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 30
Author(s):  
Minyoung Yun ◽  
Clara Argerich Martin ◽  
Pierre Giormini ◽  
Francisco Chinesta ◽  
Suresh Advani

Fiber–fiber interaction plays an important role in the evolution of fiber orientation in semi-concentrated suspensions. Flow induced orientation in short-fiber reinforced composites determines the anisotropic properties of manufactured parts and consequently their performances. In the case of dilute suspensions, the orientation evolution can be accurately described by using the Jeffery model; however, as soon as the fiber concentration increases, fiber–fiber interactions cannot be ignored anymore and the final orientation state strongly depends on the modeling of those interactions. First modeling frameworks described these interactions from a diffusion mechanism; however, it was necessary to consider richer descriptions (anisotropic diffusion, etc.) to address experimental observations. Even if different proposals were considered, none of them seem general and accurate enough. In this paper we do not address a new proposal of a fiber interaction model, but a data-driven methodology able to enrich existing models from data, that in our case comes from a direct numerical simulation of well resolved microscopic physics.


2021 ◽  
Author(s):  
Patrick Wilms ◽  
Jan Wieringa ◽  
Theo Blijdenstein ◽  
Kees van Malssen ◽  
Reinhard Kohlus

AbstractThe rheological characterization of concentrated suspensions is complicated by the heterogeneous nature of their flow. In this contribution, the shear viscosity and wall slip velocity are quantified for highly concentrated suspensions (solid volume fractions of 0.55–0.60, D4,3 ~ 5 µm). The shear viscosity was determined using a high-pressure capillary rheometer equipped with a 3D-printed die that has a grooved surface of the internal flow channel. The wall slip velocity was then calculated from the difference between the apparent shear rates through a rough and smooth die, at identical wall shear stress. The influence of liquid phase rheology on the wall slip velocity was investigated by using different thickeners, resulting in different degrees of shear rate dependency, i.e. the flow indices varied between 0.20 and 1.00. The wall slip velocity scaled with the flow index of the liquid phase at a solid volume fraction of 0.60 and showed increasingly large deviations with decreasing solid volume fraction. It is hypothesized that these deviations are related to shear-induced migration of solids and macromolecules due to the large shear stress and shear rate gradients.


2016 ◽  
Vol 94 (11) ◽  
pp. 2145-2152 ◽  
Author(s):  
Mahyar Javidi ◽  
Andrew N. Hrymak

1995 ◽  
Vol 39 (4) ◽  
pp. 795-795
Author(s):  
Yasufumi Otsubo

2018 ◽  
Vol 108 ◽  
pp. 80-92
Author(s):  
Ricardo Medina ◽  
Russell L. Detwiler ◽  
Romain Prioul ◽  
Wenyue Xu ◽  
Jean E. Elkhoury

2001 ◽  
Vol 54 (8) ◽  
pp. 503 ◽  
Author(s):  
Linggen Kong ◽  
James K. Beattie ◽  
Robert J. Hunter

n-Hexadecane-in-water emulsions were investigated by electroacoustics using a prototype of an AcoustoSizer-II apparatus. The emulsions were formed by passing the stirred oil/water mixture through a homogenizer in the presence of sodium dodecyl sulfate (SDS) at natural pH (6–7). With increasing oil-volume fraction, the particle size increased linearly after 5 and also after 20 passages through the homogenizer, suggesting that surface energy was determining particle size. For systems in which the surfactant concentration was limited, the particle size after 20 passages approached the value dictated by the SDS concentration. With ample surfactant present, the median diameter was a linear function of the inverse of the total energy input as measured by the number of passes. There was, however, a limit to the amount of size reduction that could be achieved in the homogenizer, and the minimum size was smaller at smaller volume fractions. Dilution of the emulsion with a surfactant solution of the same composition as the water phase had a negligible effect on the particle size and changed the zeta potential only slightly. This confirms results from previous work and validates the equations used to determine the particle size and zeta potential in concentrated suspensions. The minimum concentration of SDS that could prevent the emulsion from coalescing for the system with 6% by volume oil was 3 mM. For this dilute emulsion, the particle size decreased regularly with an increase in SDS concentration, but the magnitude of the zeta potential went through a strong maximum at intermediate surfactant concentrations.


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