Search Results

The “Water Spider Geometry” (WSG) configuration, representing a newly developed reference test sample designed to suitably investigate the flow and heat transfer processes relevant to cooling systems of internal combustion engines, was computationally investigated by applying a recently proposed Reynolds Stress model called the “Elliptic-Blending Model” (EBM). The WSG configuration resembles a specifically configured pipe geometry that appropriately mimics the flow phenomena encountered in cooling channels of realistic internal combustion engine, such as flow impingement and bifurcation, multiple deflections and flow confluence. The reference database, consisting of mean flow and turbulence fields, was provided by a Large-Eddy Simulation. The EBM formulation has been intensively validated by calculating numerous isothermal wall-bounded flows. The present work focuses on testing the EBM predictive performances under the conditions of non-isothermal flow scenarios.

Some widely-used scale-resolving turbulence models are comparatively assessed in simulating the aerodynamic behavior of a full-scale AUDI-A1 car configuration. The presently considered hybrid RANS/LES (RANS – Reynolds-Averaged Navier-Stokes; LES – Large-Eddy Simulation) models include the well-known DDES (Delayed Detached-Eddy Simulation) scheme and two further variable-resolution formulations denoted by PANS (Partially-Averaged Navier-Stokes; Basara, 2011) and VLES (Very LES; Chang et al., 2014). Whereas the DDES method represents the originally proposed formulation based on the one-equation Spalart-Almaras model (Spalart et al. 2006), whose RANS/LES interface position is directly correlated to the underlying grid resolution, the other two models represent ‘true’ seamless formulations, providing a smooth transition from Unsteady RANS to LES in terms of a dynamic “resolution parameter” variation.