Project
Understanding Complex fluids: Global versus local rheology of complex fluids
Complex fluids such as mayonnaise, cornstarch suspensions in water show complex flow behaviour such as spatio-temporal heterogeneities. Such flows are affected either by the boundary conditions of the flow geometries or the intrinsic properties of the constituent materials.
We modify the boundary in
We modify the boundary in flow geometries by introducing some patterns onto the wall which induces a wall roughness. We have introduced rough textured surfaces in the form of ridged geometries that can be readily fabricated using 3D printing technique. This way of patterning offers freedom to explore a wide range of wall roughness features that can be easily characterized to study their influence on the fluid flow behaviour. Using these geometries in a rheoMRI set up, we can image the different flow fields and understand how the flow fields affect each other.
To investigate the spatio-temporal heterogeneities in complex fluids, specifically in dense suspension of cornstarch particles in water, we have built a set-up by combining a rheometer with a laser speckle imaging device, referred to as rheoLSI, which can visualize the heterogeneities in the sheared suspension. These microscopic descriptions provide valuable insights into understanding and visualizing the local non-trivial discontinuous shear thickening behaviour in cornstarch suspensions.