This Week in CFD

Structured Grids

[Yes, structured grids. No, it is not 1997.]

envenio-structured-grid.png

An example from Envenio of a structured grid, part of their article on the benefits of such grids. Image from design-engineering.com. See link below.

  • Envenio cites six benefits of structured grids relative to unstructured and hybrid meshes. #4 Data locality leads to “better usage of memory bandwidth.” [Full disclosure: Pointwise provides Envenio with a preprocessing solution.]
  • Alert reader Thomas shares another example of structured grid generation, this time from the aspect of overset grids used by ONERA for a simulation of a drone. See image below. [Full disclosure: The grids were generated using Pointwise. No, I did not rig the articles to both have that tie-in.] [The article is in French which I can’t read. People who can speak three languages are called tri-lingual, those who can speak two languages are called bi-lingual, and those who can speak one language are called American.]
    • Update 18 Nov 2017: The mesh generation and CFD solution were performed by Andheo for ONERA. Sorry for any confusion and consternation.
onera-drone-pw

Overset structured surface grids on a drone for a simulation performed by ONERA. Image from andheo.fr. See link above.

 

Applications

2_khorrami_sc17_landinggear_flowfield-f

CFD image of the week. This absolutely gorgeous image (colored by velocity) is from a simulation conducted collaboratively with NASA and Boeing. Image from nasa.gov. See the full article here.

  • Use of CFD for keeping up with “the ever-changing environmental regulations that are in effect one day and repealed the next” related to NOx burner retrofits.
  • Singer and Williams Advanced Engineering used CFD to improve the aerodynamics of a 1990 Porsche 964.
  • CFD was applied to the Mars Curiosity Rover to determine the rover’s influence on its environmental sensors.
  • Use of CFD to study windage effects on superstructures helps ensure they won’t roll over in high winds. See image below.
  • CFD and NASCAR
  • CFD was used to validate the designs for the vortex impeller in a dredger. [Other than the use of CFD, this article is notable for two things. First, the product name Slurrysucker. Second, the decision in the article’s title to capitalize “Mark II” as “Mark Ii.” Even accounting for my previously noted language deficiencies, I’m fairly certain that’s not good Latin.]
numeca-fcs-3307-velocity-gust

Velocity profiles around the Damen’s FCS 3307 as the ship encounters a wind gust. Image from maritimejournal.com. See link above.

Computing

  • The SimCenter at the University of Tennessee at Chattanooga upgraded their parallel file storage capabilities to support CFD and other HPC applications.
  • Scientific Computing World published this article about ANSYS’ approach to “democratizing HPC.”
  • A similar story appears in Digital Engineering magazine about how TotalSim is moving toward Simulation as a Service.
  • Deep learning to accelerate CFD.
wind-comfort-simulations-building

CFD solution of airflow in an urban environment as computed by SimScale. Image from simscale.com. Read the full article.

Software

  • Tecplot 360 2017 R3 was released with improvements to slices and isosurfaces, new Python scripting capabilities, and more.
  • The ProLB Lattice Boltzmann CFD solver will now be distributed worldwide by Powersys.
  • Mentor’s FloEFD was recently upgraded and includes new free-surface capabilities.
  • Calling it “IP security,” Core Technologie added a Simplify module to their 3D Evolution geometry model tool that, among other things, can strip out all interior detail while leaving the exterior surfaces as a solid model.

Good Reading

  • Tech-Clarity has produced another report worth reading, Close the Engineering Skills Gap, about “preparing new graduates to be real-world ready.” Especially for all you professors.
    • While I have only scanned the report so far, something did catch my attention. Regarding the desired level of experience with engineering software tools, 75% of survey respondents ask that new graduates have experience with “practical applications to use software to solve problems” and 16% (the next highest category) wants “an understanding of the ‘picks and clicks’ to use the software.” Because in my mind both of those desires focus on the use of a specific piece of software I will repeat myself by saying an undergraduate engineering education is not a trade school. IMO, students shouldn’t learn how to use any particular CFD code (for example). They should learn in general how CFD codes are applied and how to use their own general engineering judgement to validate the answers. But that’s just my opinion; I could be wrong.
  • NAFEMS’ online resource center includes many articles on physics, numerical methods, and other topics that are freely available – no membership required.
  • Gas Compression Magazine includes a nice profile of our friends at Convergent Science. [Friends despite this “never generate a mesh again” business. Oh, wait – they’re calling it “autonomous meshing” now. I can live with that.]
  • The CFD Israel blog makes predictions about CFD in 2030.
  • A New Subgrid Characteristic Length for Turbulent Simulations on Anisotropic Grids
  • Here’s a cool story from alert reader Alberto about a mathematical hobbyist who discovered four pentagonal tilings not included in a 1975 Scientific American article, to be confirmed only recently by a computer-assisted proof.
  • Visualizing Data presents their best of the visualization web for September 2017.

Events & Jobs

  • The 10th International Conference on CFD (ICCFD10) will be held 9-13 July 2018 in Barcelona. The call for papers is now open with a due date of 15 January.
  • The Future CFD Technologies Workshop, to be held the weekend prior to AIAA SciTech in Orlando, has published their agenda. Registration for this event is still open.
  • Unilever seeks a CFD Engineer in the UK.
  • There’s still time to register for the Pointwise Meshing Technology Conference in Stuttgart on 4-5 December. Register today, come meet us, and let’s talk technically about:
    • elevating linear meshes to high polynomial degree
    • preparing geometry models for meshing
    • learning from the 1st AIAA Geometry and Mesh Generation Workshop
    • understanding the benefits and drawbacks of meshing strategies on CFD results for two specific simulations
    • generating structured grids
    • applying hybrid meshing techniques to complex geometry

Would you pay $450,000,000 for this painting?

By now most of you have heard about the record-setting sale at auction of Leonardo Da Vinci’s painting Salvatore Mundi for $450,000,000 ($400,000,000 for the painting, $50,000,000 to Christie’s). We could have fun debating (?) whether or why it’s worth that much.

But more to the subject of this blog is Robert Delaunay’s Windows Open Simultaneously, shown below. This painting truly is an abstract representation of a tangible object so take a moment to ponder it before clicking the link in the caption. We could have another fun conversation about the motif of windows in painting (e.g. Diebenkorn, Scully).

I’ll just ruin it all by pointing out that the triangles in the painting certainly don’t meet the Delaunay criteria (you’d think he’d know better). Plus I’m certain that one of you is thinking that instead of Windows Open it should be Linux Open or Windows Closed.

Windows Open Simultaneously (First Part, Third Motif) 1912 by Robert Delaunay 1885-1941

Robert Delaunay, Windows Open Simultaneously (First Part, Third Motif), 1912. source

Bonus: Alert reader Ray shared with me the Void Rug. How I’d love to have one of these in front of my desk. Alas, they’re not currently for sale.

Void-Rug_01_Jarvie

The Void Rug will keep people on their toes. Image from scottjarvie.co.uk. See link above.

And one last thing: Next week in the U.S. we celebrate the Thanksgiving Day holiday on Thursday and take Friday off to recover from the celebrating. This Week in CFD will therefore be taking next week off. Happy Thanksgiving to all.

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2 Responses to This Week in CFD

  1. jstults says:

    students shouldn’t learn how to use any particular CFD code (for example). They should learn in general how CFD codes are applied and how to use their own general engineering judgement
    I think you’re right. There’s probably a place for using a CFD code in the practical part of courses that are not “CFD courses”, e.g. generating pre-test predictions in an experimental fluid dynamics course, or as a design and analysis tool in a capstone design-build-fly sequence. The focus for engineering education should never be just turning the crank on a particular code. Plenty of opportunity outside the curriculum for a young engineer to do on-the-job training, or a short-course to learn someone’s particular software.

    (my love for structured grids will never die!)

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