Rayleigh Taylor instability
This image shows a visualization of an ensemble of 25 simulations. The upper left shows a single simulation, rendering the speed from a Rayleigh Taylor instability. The other three images are color coded to show which simulations have the maximum speed at any given point. The bottom right shows that the simulations that use extreme values for their viscosity coefficients (blue for low values of the coefficient and red for high values) tend to contain the maximum speed over all 25 simulations.