Tech Briefs

Analysis of an Engine Exhaust Manifold Using the Shear Stress Transport Model

The animation above shows a particle trace in the exhaust manifold of a Volvo Penta 6-cylinder D6 diesel engine. The results were obtained using the Shear Stress Transport (SST) turbulence model, which is available in ADINA 8.3.

A detail of the manifold with pressure contours is shown below. The Reynolds number at the inlets of the manifold is approximately 13,000. The walls are all modeled as no-slip. All the inlets have the same prescribed velocity and prescribed turbulence quantities, k and ω. There are 586,120 FCBI-C elements (~3.5 million equations) in the model.

The SST turbulence model exploits the benefits of the k-ω model in the sub- and log-layer and it switches to the standard k-ε model in the wake region of the boundary layer and in the free shear layers. The main benefit of the SST model is improved accuracy of results in the modeling of flows with adverse pressure gradients or pressure-induced separation.

Courtesy of Volvo Penta, Göteborg, Sweden