Benefits
Accurate, Robust and Scalable CFD Solver:
HyperWorks VWT is powered by Altair’s computational fluid dynamics solver, AcuSolve®, a general-purpose, finite element based flow solver providing fast turnaround times, accuracy and robustness.

Architected for parallel execution on shared and distributed-memory computer systems, using a hybrid parallelization technique, AcuSolve provides fast and efficient transient and steady-state solutions for unstructured grids, and it is capable of scaling over a large number of computing cores.

HyperWorks VWT utilizes Reynolds-Averaged Navier-Stokes (RANS) and Detached-Eddy Simulation (DES) technology to model turbulent flows and to predict the flow field. DES technology combines fine-tuned, statistical RANS technology for modeling near walls and attached boundary layers with the ability of large-eddy simulation (LES) to model the separated regions in the wake behind the vehicle. Accurate external aerodynamics results are achieved for both, steady-state simulation using the RANS approach when physics allows and transient simulation using the DES approach.

AcuSolve’s fluid structure interaction (FSI) capabilities are included in VWT to support studies of flexible components in an external flow field.

Rotating parts, e.g. wheels, are modelled by prescribing a tangential wall velocity to include rotational effects into the simulation. For automotive use cases, heat-exchangers or condensers are modelled with a porous material model to consider the pressure drop through the components. The fluid material used during the simulation is defined via density and viscosity, and can be adapted to model for example water or air at a specific temperature.

Advanced Meshing
HyperWorks VWT comes with a fast and efficient unstructured volume mesher including boundary layer generation. User defined volume mesh refinement zones are used to create a locally refined volume mesh to capture important flow phenomena, e.g. the wake of a vehicle or a building. Parameters for boundary layer meshing can be defined globally or on a part basis to have maximum control of the total element count and use refined layers only in regions where it is necessary. Volume meshing for an external automotive aerodynamics analysis (including underbody, underhood compartment and boundary layers) is typically done in a few hours.

Highly Automated and Streamlined Workflow Process
VWT comes with a friendly and intuitive user environment. It is an all-in-one environment where users can import the surface mesh (water tight mesh), set up the problem, submit the simulation and obtain a final report.

The setup process is highly automated, with a minimum number of parameters, and without compromising the solution quality. Additional controls over the various parameters are provided in the user environment.
The simulation can be easily submitted to high-performance computing systems to expedite memory and compute-intensive tasks such as volume meshing, solving and post-processing.
A report containing problem setup, mesh statistics and results is generated automatically after completion of the simulation. In addition, advanced CFD post-processing may be performed for the most complex and large CFD data visualization, interactively or via batch processing mode.

Capabilities:
Pre-processing
– Meshing
– Predefined mesh settings available, coarse/medium/fine
– User defined volume refinement zones, also for individual parts

– User defined Boundary Layer (BL) parameters, globally or on part basis.
– Exclude parts from BL growth to reduce total element count
– Advanced BL meshing algorithms to deal with complex geometry

– Analysis setup
– Definition of rotating wheels or radiators with a few mouse clicks
– Option for moving wind tunnel ground
– Automatic computation of vehicle’s frontal reference area

Solver
– Based on Altair’s CFD solver AcuSolve
– Low requirement on element quality
– High scalability even for low mesh-node/compute-node ratio
– Robust Fluid-Structure-Interaction (FSI) capabilities
– Transient & steady state simulation
– RANS and DES turbulence modeling

Post-Processing
– Automatic report generation containing
– Summary of case setup
– Mesh statistics
– Numerical results, e.g. drag coefficient or y+ plots
– User defined sections with contour plots
– User defined probe points to monitor the evolution of the flow field in a particular location