You may have heard before that “80% of the time spent on CFD simulation for aerodynamics is used just for preparing the set-up of the case”. Typical challenges in the simulation preparation process are still: poor quality of the available CAD, resulting in dirty geometries containing holes and cavities, complex geometries, resulting in a large amount of manual input to create a quality mesh, and difficulty to quickly create design alternatives for iterative testing.
NUMECA’s challenge for advancing its meshing tools, and staying ahead of the CFD race, is therefore clear: achieve the fastest possible turnaround times for the highest quality of meshes. With the latest version of HEXPRESS™/Hybrid incorporating AutoSeal, we have done just that.
HONDA has been using HEXPRESS™/Hybrid for many years now for their automotive designs, and the AutoSeal technology made a real difference for them. Closing the holes and cavities of their cabin model with AutoSeal made a huge difference in speed, with the same excellent, detailed result.
Mr Akio Takamura from HONDA Automotive testifies: “A skilled engineer typically needed one full week to close all the holes of the cabin space. Thanks to AutoSeal this is now reduced to 1 hour! It's robust too, we tested it on 10 different models with 100% success rate.”
|Time to close in CAD software: 1 week||Time to close in AutoSeal: 1 hour|
AutoSeal automatically creates closing surfaces for dirty geometries containing holes and cavities. A huge time-saver, as this is a tedious job the engineer used to have to do manually.
To make sure using these meshes gives the same results as the CAD software models do, HONDA Automotive compared the impact in terms of aerodynamic performances.
“We compared aerodynamic performances on over 10 different models, by looking at aerodynamic coefficients and heat exchanger passing wind speed, and found little to no difference.”
“Meshing is so fast!” stated Mr. Akio Takamura. “We have observed speed up improvements for each version of HEXPRESS™/Hybrid for the past years, but this one is a major breakthrough.''.
|“Meshing is so fast! We have observed speed up improvements for each version of HEXPRESS™/Hybrid for the past years, but this one is a major breakthrough.'' - Mr. Akio Takamura|
To speed up the meshing process even more, HONDA is using another very useful advantage of HEXPRESS™/Hybrid: meshing in parallel using distributed memory. This means that meshes can be generated in parallel on several computers or cluster nodes. The results: tens of millions of cells can be created in a matter of minutes! The graph and table below give you an idea of what our mesh generator can achieve on a typical case. A 43M cell mesh for instance, running on 192 cores, can be created in less than 4 minutes. Mesh generation thus becomes a pre-processing step of the solver, which will be run on the same number of cores and partitions.
Faster turnaround times will enable our automotive customers to save millions of euros on digital prototypes every year. And it will allow the engineers to dedicate their time to what counts: optimizing their designs.
|Faster turnaround times will enable our automotive customers to save millions of euros on digital prototypes every year.|