Laboratory

Welcome to Jacob McFarland’s Fluids Mixing and Shock Tube Laboratory page (FMSTL). Our research focus on multiphase fluids mixing created by shock

Ares simulations (LLNL) showing the effect of particle size on an shocked interface between clean gas and gas-particle mixture. Time proceed from left to right in the images where the rightmost time is approximately 4ms after shock interaction

Ares simulations (LLNL) showing the effect of particle size on an shocked interface between clean gas and a gas-particle mixture. Time proceeds from left to right in the images, where the rightmost time is approximately 4ms after shock interaction

accelerations. We are interested in  hydrodynamic instabilities and their evolution towards turbulent mixing for multiphase problems. These systems arise in many applications including cosmic dust processing by supernovae, shock processing of condensing droplets in supersonic ejectors, shock induced mixing of air and fuel droplet mixtures in scramjets, and in high energy explosions where particles are ejected from boundaries.

We study these problems using a combination of both experiments and high performance simulations. The centerpiece of our lab is our multiphase shock tube facility. This facility consists of an approximately 30 foot long high strength steel tube which allows us to generate controlled shock waves at velocities up to Mach 3.0 into atmospheric pressure air. The tube employs high strength windows to allow optical access for our high speed laser diagnostic system which can make particle imaging velocimetry or planar laser induced fluorescence measurements. In addition to our experiments we work with high performance multiphase computing codes at Los Alamos and Lawrence Livermore National Laboratories.  We also us our own multiphase particle package which is implemented in the FLASH code and run on our supercomputing node here at the University of Missouri.

A turbulent interface between nitrogen and carbon dioxide (white) created in our shock tube and illuminated by our laser system.

A turbulent interface between nitrogen and carbon dioxide (white) created in our shock tube and illuminated by our laser system.

Our current focus is on understanding the role of particle properties on the evolution of shock-driven particle-gas instabilities. Our computational work has shown hydrodynamic mixing can be damped by the presence of large, slow, particles. We have also developed evaporation models which show that evaporation of particles also damps the vorticity deposition on these particle-gas interfaces. Our lab is also interested in the evolution of magnetohydrodynamic instabilities where a magnetic field may be used to damp mixing,  multiphase flows where particles, active or passive, may be used to enhance heat transfer, and the production of ejecta, particles, from boundaries in high energy blast waves.