Atwood effects on nonlocality of the scalar transport closure in Rayleigh-Taylor mixing

This is the authors' abstract. We don't add key points for this paper.

This work seeks to understand the importance of nonlocality in modeling scalar transport in turbulent Rayleigh-Taylor instability (RTI) at different Atwood numbers. We apply the Macroscopic Forcing Method to determine moments of the eddy diffusivity from high-fidelity numerical simulations of RTI. We additionally present a framework for incorporating nonlocality for modeling RTI at different Atwood numbers. We find that nonlocality is important for modeling RT and appears to increase in importance with Atwood number.