Los Alamos National Laboratory

Los Alamos National Laboratory

Delivering science and technology to protect our nation and promote world stability

Fluid Dynamics

Specializing in high-speed, laser-based diagnostics to reveal instabilities in variety of extreme conditions relevant to Laboratory's nuclear deterrence efforts


New experimental facilities for multiphase flows, mixing, turbulence

Multiple challenges exist in understanding the physics of turbulent mixing, especially under extreme conditions. When there are shocks, strong density gradients, multi-phase flows, and persistence of initial conditions effects at late times in the flow, traditional turbulence models are not applicable so we must create new models.

The Extreme Fluids Team provides insights into the physics of turbulent mixing by making new measurements of important turbulence quantities.

We work closely with colleagues in the Center of Mixing Under Extreme Conditions to use the experimental data for code validation and model development.

Our three experimental facilities target high-priority physics areas for modeling and simulation.

  • Vertical Shock Tube: for shock-driven mixing of two fluids that are struck by a shock wave. We use simultaneous velocity and density field diagnostics, as well as tomographic particle image velocimetry (PIV), to measure turbulence quantities in these unsteady flows.
  • Turbulent Mixing Tunnel: for the mixing of two fluids in a subsonic environment. We also measure turbulence quantities for the development of better variable-density mixing models.
  • Horizontal Shock Tube: for the response of particles and droplets in a gas to the passage of a shock wave. We use an 8-pulse laser system with a high-speed camera to measure particle velocities and accelerations over short time scales, thereby predicting the motion of the particles in an unsteady flow.

Unraveling the process of multiphase flows, mixing, and turbulence is key to the Laboratory’s nuclear deterrence mission.

Our experiments are directly informing modeling efforts, and our team works closely with modeling and simulation colleagues to better understand and predict these complex flows.