Analog of discontinuous shear thickening flows under confining pressure
(2017) In Physical Review Fluids 2(8). Abstract
We use twodimensional numerical simulations to study dense suspensions of nonBrownian hard particles using the Critical Load Model (CLM) under constant confining pressures. At constant packing fraction this simple model shows shear thickening as the tangential forces get activated upon increased shear stresses. By parameterizing a simple binary system of frictional and nonfrictional particles of different proportions we show that the jamming packing fraction, at which the viscosity diverges, is controlled by the fraction of frictional contacts. The viscosity of dense suspensions can thereby be expressed as a function of the fraction of frictional contacts as well as the packing fraction of solid particles. In addition, we show that... (More)
We use twodimensional numerical simulations to study dense suspensions of nonBrownian hard particles using the Critical Load Model (CLM) under constant confining pressures. At constant packing fraction this simple model shows shear thickening as the tangential forces get activated upon increased shear stresses. By parameterizing a simple binary system of frictional and nonfrictional particles of different proportions we show that the jamming packing fraction, at which the viscosity diverges, is controlled by the fraction of frictional contacts. The viscosity of dense suspensions can thereby be expressed as a function of the fraction of frictional contacts as well as the packing fraction of solid particles. In addition, we show that there exists a simple relationship between the fraction of frictional contacts and the two control parameters (under confining pressure): the viscous number J and the ratio between the repulsive barrier force and confining pressure. Under confining pressures the viscosity curves are found to depend on the shear protocol, with the possibility of yielding negative dynamic compressibility, an analog to the discontinous shear thickening found at high but constant packing fractions for the same system.
(Less)
 author
 Dong, Junhao ^{LU} and Trulsson, Martin ^{LU}
 organization
 publishing date
 20170801
 type
 Contribution to journal
 publication status
 published
 subject
 in
 Physical Review Fluids
 volume
 2
 issue
 8
 external identifiers

 scopus:85035317858
 wos:000408632300001
 DOI
 10.1103/PhysRevFluids.2.081301
 language
 English
 LU publication?
 yes
 id
 f37f0100359e400a9aa9e44e788b9d74
 date added to LUP
 20171212 14:23:07
 date last changed
 20180116 13:27:44
@article{f37f0100359e400a9aa9e44e788b9d74, abstract = {<p>We use twodimensional numerical simulations to study dense suspensions of nonBrownian hard particles using the Critical Load Model (CLM) under constant confining pressures. At constant packing fraction this simple model shows shear thickening as the tangential forces get activated upon increased shear stresses. By parameterizing a simple binary system of frictional and nonfrictional particles of different proportions we show that the jamming packing fraction, at which the viscosity diverges, is controlled by the fraction of frictional contacts. The viscosity of dense suspensions can thereby be expressed as a function of the fraction of frictional contacts as well as the packing fraction of solid particles. In addition, we show that there exists a simple relationship between the fraction of frictional contacts and the two control parameters (under confining pressure): the viscous number J and the ratio between the repulsive barrier force and confining pressure. Under confining pressures the viscosity curves are found to depend on the shear protocol, with the possibility of yielding negative dynamic compressibility, an analog to the discontinous shear thickening found at high but constant packing fractions for the same system.</p>}, articleno = {081301}, author = {Dong, Junhao and Trulsson, Martin}, language = {eng}, month = {08}, number = {8}, series = {Physical Review Fluids}, title = {Analog of discontinuous shear thickening flows under confining pressure}, url = {http://dx.doi.org/10.1103/PhysRevFluids.2.081301}, volume = {2}, year = {2017}, }