Neural network-based modelling of unresolved stresses in a turbulent reacting flow with mean shear

Data-driven methods for modelling purposes in fluid mechanics are a promising alternative given the continuous increase of both computational power and data-storage capabilities. Highly non-linear flows including turbulence and reaction are challenging to model, and accurate closures for the unresolved terms in large eddy simulations of such flows are difficult to obtain. In this study, we investigate the use of artificial neural networks for modelling an important unclosed term namely the unresolved stress tensor, in a highly demanding turbulent and reacting flow, which additionally includes mean shear. The performance of the neural network-based modelling approach is conducted a priori following a coarsened mesh approach, and compared against the predictions of eight other classic models in the literature, which include both static and dynamic formulations.