Assessment and modification for Reynolds stress transport turbulence model flow

The Launder-Shima1 Reynolds stress model is implemented in an existing scalable parallel flow solver. The complexity of the dissipation equation for this model adds stiffness and instability characteristics to the equation system, particularly when integrating to the wall with sub-layer resolution. In the present work, the dissipation equation from Launder-Shima model was replaced by the well known k-ε model dissipation equation in an effort to produce a more robust and stable Reynolds stress model. Computations for standard flat plate, square cylinder, backward facing step, surface mounted cube, and DARPA SUBOFF body are compared to experimental data for both models. The modified model showed a significant improvement in stability and robustness over the Launder-Shima model, while keeping the same flow prediction accuracy.