(3cg) Fluid Mechanics of Complex Fluids: From Advanced Materials to Biomedical Applications

Complex fluids are ubiquitous in nature and technological settings. Some examples of great interest include nanoparticle suspensions, blood, and swimming micro-organisms among others. The key feature of these systems is that their bulk properties are determined by their underlying microstructure, which in turn is strongly influenced by the complex hydrodynamic interactions between the constituent particles. A particular focus of my research has been to develop the state of the art numerical algorithms to accurately and efficiently compute the hydrodynamic interactions between the suspending particles, thus enabling predictive simulations on these systems. In this poster, I will present two specific examples from my research showing the power of these predictive simulations. In the first example, I will discuss the complex orientation behavior observed in sheared suspensions of non-spherical dicolloidal particles. A dicolloidal particle is modeled as two fused spheres of varying radii and center to center separation. A novel theory relating the orientation behavior to the observed normal stress difference in the suspension will be presented. These simulations were carried out with a Particle-Mesh-Ewald Stokesian Dynamics technique developed for an arbitrarily shaped rigid particle. In the second example, I will discuss studies related to the blood flow in the microcirculation. Microcirculation refers to the part of the circulatory system with the smallest blood vessels. As a model problem, I will present results for the flow induced segregation in suspensions of mixtures of deformable capsules with different rigidities. Flow induced segregation based on particle rigidity has potential applications in the separation or detection of diseased red blood cells from their normal counterpart. These simulations were carried out with an accelerated implementation of the boundary integral method valid for an arbitrary geometry. In addition to these problems, several other future directions will be discussed with relevance to biomedical and advanced materials research.