Virtual Wind Tunnel 13.1 Release Notes Introduction Virtual Wind Tunnel is a vertical application to perform wind tunnel simulations of vehicles in an efficient, accurate and robust manner. An intuitive user interface streamlines the process to define parameters for meshing as well as CFD case setup. The definition of physical objects, like rotating wheels or heat exchangers, includes intelligent automation to reduce the user interaction to a minimum. Automatic report generation is embedded in the system to summarize information about the numerical model, such as mesh statistics or boundary conditions, as well as the aerodynamic results, like lift and drag coefficient. Based on Altair’s CFD solver AcuSolve, Virtual Wind Tunnel delivers highly accurate results and provides a platform for short product development cycles. 13.1 Release Notes Highlights Supported physics • − Transient/steady state − Turbulence − Rotating wheels, moving wind tunnel ground − Heat-exchanger − Fluid-Structure-Interaction (FSI) • Based on AcuSolve CFD technology − Fast, robust and accurate solutions for transient and steady state applications • Automatic and fast volume meshing − User defined volume mesh refinement zones − Boundary layer (BL) parameter definition on a part level − Exclude parts from BL generation to reduce total element count • Dimension measurement utility to ensure model is in correct unit system • Vehicle positioning tool • Accurtate frontal area calculation of vehicle • Result output control • Automatic reporting − Report generation containing aerodynamic results, such as drag coeff. − User defined section cuts and probes for post-processing Virtual Wind Tunnel 13.1 Release Notes Proprietary Information of Altair Engineering 1 New Features • Definition of planar section cuts for result contour plotting, e.g. velocity magnitude on the symmetry plane of the vehicle. The plots will be included in the automatically generated report. A selection of different results type are available, e.g. pressure or velocity. The legend range for each result type can be adjusted globally or individually for each section cut. • User defined probe points to monitor the evolution of the flow field in a particular location, e.g. pressure fluctuations over time. The plots will be included in the automatically generated report. A selection of different result types are available, e.g. pressure or velocity. The legend range for each result type can be adjusted globally or individually for each probe point. • Support of user defined fluid material by specifying density and viscosity of the material. • Implementation of a new algorithm to compute projected frontal areas of vehicles with high accuracy. • Wind tunnel inflow speed can be defined by a velocity magnitude and an angle around the z-axis, to model situations where side wind effects occur. Enhancements • Definition of number of cores to be used for the CFD analysis has been moved to the run dialog. • When clicking “Export” in the run dialog the *.stmod file of the current session will be exported to the run directory. • Version number of the CFD solver AcuSolve used to perform the analysis is included in the report. • Refinement zones are displayed in the graphical area only when the user has entered the refinement zone mode. • Added a vehicle model for the tutorial into the installation directory, surface mesh and geometry. Resolved issues • If a surface mesh model, consisting of quad elements only, is not touching the wind tunnel ground, the surface model is removed from the analysis domain. • Deleting an analysis from the Run History table does not delete all files generated during the corresponding CFD analysis. • If the surface mesh model is not touching the wind tunnel ground, the ref. zones are ignored for surface meshing and the wind tunnel ground is meshed with a constant element size. • In case the surface mesh model is cutting the top of the wind tunnel, the mesh intersection step fails and an error message is displayed: “can’t perform mesh intersection”. • The default element size for refinement boxes of type Around Part or Around Body is 1m. Note • • It is necessary to install both the Virtual Wind Tunnel 13.1 package as well as the AcuSolve 13.0.302 package to access the new functionality of VWT. For certain configurations, VWT 13.1 requires the Altair License Manager version 12.1 to be installed. Virtual Wind Tunnel 13.1 Release Notes Proprietary Information of Altair Engineering 2