InnovMetric Software
Digital Wind Tunnel Testing is replacing expensive, time-consuming testing techniques
Fluid flow analysis is the study of how fluids, such as liquids, air, and other gases move in and around solid objects. Most major car manufacturers worldwide face fluid flow problems in their design work, such as airflow over automobile surfaces measuring lift, drag, yaw, and friction.
Typically, traditional fluid dynamics analysis are conducted through wind tunnel testing, an expensive and time-consuming operation that requires well-trained technicians. A computational fluid dynamics (CFD) analysis empowered by PolyWorks offers benefits not achievable with traditional simulations.
The emergence of 3D digitizing technology has revolutionized the way to analyze Fluid Flow by opening the door to Digital Wind Tunnel Testing. The millions of data points captured by the non-contact 3D digitizers represent an excellent source of information for digitally simulating fluid flow, and replicating typical wind tunnel testing analysis at a fraction of usual cost and time. PolyWorks' unique tools have enabled major car manufacturers to reduce the time required to prepare a CFD-ready polygonal model from seven days to one day.
Traditional CFD Versus PolyWorks
There are two traditional methods for conducting CFD analyses on
physical prototypes that are both costly and time-consuming, requiring
multiple iterations.
- Approach #1: Aerodynamic simulations are conducted through physical wind-tunnel testing of clay models.
- Approach #2: The clay model is digitized using a non-contact 3D digitizer.
- NURBS surfaces are created from the digitized points in rapid-surfacing software.
- Surfaces are imported into CAD software for modifications.
- CAD surfaces are tessellated and optimized.
- Polygons are imported into CFD software for analysis.
Poly Works Approach
The PolyWorks approach is quick and straightforward. First, a clay model is digitized using a non-contact 3D digitizer. The resulting point clouds are quickly aligned and meshed in PolyWorks to create a single polygonal model. All model editing is conducted in PolyWorks, including feature curve reconstruction, removal of unnecessary details, insertion of CAD surfaces, and triangle reduction and optimization.Finally, an optimal polygonal model is exported by PolyWorks as an STL file to Exa's PowerFlow for thorough CFD simulation. PowerFlow transforms the polygonal model into a mesh of Voxels to describe the solid surface, and calculates how particles are allowed to move and collide with each other and with the solid surface over a real-time period. A PowerFlow CFD analysis empowered by PolyWorks offers a series of benefits simply not achievable with physical wind tunnel simulations, and gives specialists of the automotive industry unprecedented insight into fluid flow behavior.
More Efficient CFD Analysis
The
entire process takes only one to two days, compared to up to a week for
other approaches. A faster CFD analysis process allows engineers to
analyze more models and to explore more design possibilities. During
conceptual design modifications to the model can be done directly in
the PolyWorks environment--there is no need for additional software
systems. Because PolyWorks' polygons are CFD-ready--engineers' time is
spent on results analysis instead of set up, data collection, and
editing.
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