Reynolds Stress
Reynolds stress, representing the fluctuating momentum transport in turbulent flows, is a crucial yet challenging aspect of fluid dynamics modeling. Current research focuses on improving Reynolds-Averaged Navier-Stokes (RANS) simulations by developing data-driven closure models, often employing neural networks (including Graph Neural Networks) to predict the Reynolds stress tensor or its divergence, sometimes incorporating Bayesian methods to quantify model uncertainty. These advancements aim to enhance the accuracy and reliability of RANS simulations, particularly in predicting complex flows, with implications for various engineering applications such as turbomachinery design and virtual certification processes. Explainable AI techniques are also being used to better understand the underlying physics of turbulence and identify regions where model predictions are less accurate.