Studying Spontaneous Stochasticity in Turbulence via Large-Scale Direct Numerical Simulations

Past CoPI:	alexander migdal	New York University
Abstract:	This project investigates spontaneous stochasticity in turbulent flows—whether infinitesimally small perturbations can lead to fundamentally different flow realizations at high Reynolds numbers despite deterministic governing equations. The research will use large-scale direct numerical simulations (DNS) of homogeneous isotropic turbulence to evolve pairs of nearly identical turbulent flows and quantify how predictability changes as the Reynolds number increases. The simulations will also examine passive scalar transport (e.g., temperature or pollutant mixing) to determine how uncertainty in the velocity field influences scalar transport and dissipation. ACCESS CPU resources on Stampede3 will be used for production DNS, passive scalar simulations, and large-scale post-processing of the resulting datasets. Computations will be performed using the PI's massively parallel pseudo-spectral DNS and analysis codes together with the FFTW library for distributed-memory fast Fourier transforms (FFTs) and the VisIt software package for visualization and analysis.

2026	TACC Dell/Intel Sapphire Rapids, Ice Lake, Skylake (Stampede3)	100,000.0 Node Hours
2026	TACC Long-term tape Archival Storage (Ranch)	2,000.0 GB
The estimated value of these awarded resources is $20,100.00. The allocation of these resources represents a considerable investment by the NSF in advanced computing infrastructure for the U.S. The dollar value of the allocation is estimated from the NSF awards supporting the allocated resources.
2023	TACC Dell/Intel Sapphire Rapids, Ice Lake, Skylake (Stampede3)	75,000.0 Node Hours
2023	TACC Long-term tape Archival Storage (Ranch)	6,000.0 GB
The estimated value of these awarded resources is $15,300.00. The allocation of these resources represents a considerable investment by the NSF in advanced computing infrastructure for the U.S. The dollar value of the allocation is estimated from the NSF awards supporting the allocated resources.

2021	TACC Dell/Intel Knights Landing, Skylake System (Stampede2)	60,740.0 Node Hours
2021	TACC Long-term tape Archival Storage (Ranch)	500.0 GB
The estimated value of these awarded resources is $15,793.10. The allocation of these resources represents a considerable investment by the NSF in advanced computing infrastructure for the U.S. The dollar value of the allocation is estimated from the NSF awards supporting the allocated resources.

Topological vorticity sheets and scalar triple correlations in turbulence