# Graduate Student / Postdoc Seminar

#### Simulating Passive and Active Brownian Suspensions of Particles

**Speaker:**
Aleksandar Donev

**Location:**
Warren Weaver Hall 1302

**Date:**
Friday, March 27, 2015, 1 p.m.

**Synopsis:**

I will describe how to model Brownian suspensions of passive or active particles and rigid bodies at zero Reynolds number. I will first explain an immersed boundary approach where spherical particles are represented as regularized Stokeslets or 'blobs'. More complex rigid bodies suspended in fluid can be represented with different degrees of fidelity by enforcing a rigidity constraint on a collection of blobs resolving the body to some degree of fidelity. Thermal fluctuations and thus Brownian motion can be consistently modeled by including a fluctuating (random) stress in the momentum equation, as dictated by fluctuating hydrodynamics. Implementing all of this in practice requires some sophisticated numerical linear algebra which I will discuss in some detail.