Woodruff School of Mechanical Engineering

Mechanical Engineering Seminar


An Overview of Sierra Mechanics as Applied to Multiphysics Problems with a Detailed Study into the Nonlinear Behavior of a Coupled Piston Fluid System


Dr. Jonathan Clausen


Sandia National Laboratories


Tuesday, August 30, 2016 at 12:00:00 PM


Love Building, Room 210


Dr. Cyrus K. Aidun


In the first part of the talk, I will give a high-level overview of Sierra Mechanics, which is a suite of finite-element applications developed at Sandia National Laboratories for the study of a wide range of physical phenomena spanning the disciplines of solid mechanics, structural dynamics, aerodynamics, and thermal-fluids. The focus of the discussion will be on the Sierra Multimechanics module with an emphasis on multiphase thermal-fluid applications. In the second part of the talk, I will outline the development of a sliding mesh scheme within Sierra, and the usefulness of such a scheme for performing simulations of a coupled piston-fluid system. This system is of particular interest since it displays large nonlinearities when subjected to a vibrational acceleration field. These nonlinearities create counter-intuitive behaviors, which include a large rectified (net) force on the piston. Finally, I will discuss the Sierra Mechanics team's approach to handling next-generation computing platforms using the Kokkos library. These next-generation platforms are becoming increasingly heterogeneous as they combine CPUs, GPUs, and computational accelerators, and applications must be able to leverage these resources in a portable fashion. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.


Jonathan Clausen is a research engineer at Sandia National Laboratories, where he has worked since 2010. He graduated with a bachelor’s degree in Mechanical Engineering from Clemson University in 2004, and a doctoral degree from the Georgia Institute of Technology in 2010. Jonathan Clausen’s doctorate research focused on using the lattice Boltzmann method to probe the rheology and microstructure of noncolloidal suspensions of deformable particles. His research interests since joining Sandia include multiphysics applications of the finite element method, software design and architecture, and high-performance computing.