This Is How I Glyph – Squeeze Con

squeezeCon

Connector creation and manipulation is one of the most important, but tedious, tasks when creating multiblock structured topologies. You may find yourself repeatedly copying and pasting the same connector to construct a wireframe that defines the blocking strategy in a particular region of the mesh. An example of this is a quarter O-H topology often used when meshing a fillet as illustrated in the image above.

When meshing something like a fillet, you may already have domains defined at either end of the geometry and would simply like to connect them using a connector that retains the same basic shape and distribution as an existing connector. To do this you first select a connector, copy it, paste it, and then translate it to a new position. Once the translation has been applied, a second transformation is necessary to constrain the opposite end of the connector. This is accomplished by scaling the connector that was just translated so that it is positioned between two points. At the end you have squeezed a new, similar connector between two new points.

The SqueezeCon.glf script automatically copies and scales a connector to fit between two points reducing the multistep transformation process described above down to a single step. Simply select a connector, execute the script, and select the two points you would like to use as the end points of the new connector. The video below demonstrates how to use this script when creating a quarter O-H topology for a fillet.

To download this script directly, you can use this link. If you would like to visit the repository on GitHub, then please visit https://github.com/pointwise/SqueezeCon.

Do you have an idea or a Glyph script you’ve written that you would like to share with us? Let us know in the comments below or on Twitter @Pointwise.

Happy scripting!

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This Week in CFD

Reading

  • Meshing and preprocessing [Are they the same thing? Does pre- include meshing?] are a big part of the free, no-registration report from Tech Clarity on Addressing the Bottlenecks of FEA Simulation.
    • Pre-processing is the largest time component of simulation, requiring 38%. [Which is better than the oft-quoted 75% for CFD.]
    • The best practices of high performers in this area include prioritizing automation while retaining control.
  • Vox wrote about the seven biggest problems facing science. “[Scientists’] careers are being hijacked by perverse incentives.”  #4 Peer review is broken. [I’ll be interested to read your thoughts on this topic in the comments.]
Gratuitous mesh image.

Gratuitous mesh image.

Pointwise News

Applications & Events

Software

  • Autodesk is offering a technology preview of Project Calrissian for CFD, a mashup of Autodesk Flow Design and Project Ventus for CFD.
  • Beta CAE announced v17.0.0 of their software suite.
  • Those of us who program/programmed for a living will probably enjoy looking at the source code from the Apollo 11 guidance computer.

Finding Meshes in Art IRL

There’s nothing like viewing great works of art with your own eyes. And it’s a bonus when you [OK, when I] can find meshes in them. That’s exactly what happened yesterday when I toured The Modern Art Museum of Fort Worth with two visiting CFD luminaries. (Yes, there are more CFDers than just me who appreciate modern and contemporary art.) We were there primarily for the Frank Stella Retrospective but also explored the museum’s permanent collection on the second floor.

Stella’s more recent work involves CAD software and 3D printing which means that I might be able to have a quasi-intelligent conversation with him about his process. (Unlike paint on canvas about which I know vastly less.) What’s shown below is a detailed view of one of Stella’s painting/collages that incorporates a lot of mesh-like components.

Frank Stella, close-up detail. (I forgot the name of the work.)

Frank Stella, close-up detail. (I forgot the name of the painting.)

The Modern’s collection includes a massive work by Mark Bradford who, like another favorite painter of mine Callum Innes, uses a reductive technique. Whereas Innes uses turpentine or something similar to remove paint, Bradford uses a sander to carve down into layers of material he previously applied.

Mark Bradford, close-up detail. (I forgot the name of the painting.)

Mark Bradford, close-up detail. (I forgot the name of the painting.)

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I’m Brody Nutt and This Is How I Mesh

Brody Nutt, Intern on the Technical Support Team.

Brody Nutt, Intern on the Technical Support Team.

I am from Overland Park, Kansas, which is a suburban city just outside of Kansas City, Missouri. I ended up in Texas through my studies at Texas Christian University (Go Frogs!) and have enjoyed being here very much. I am currently pursuing a B.Sc. degree in mechanical engineering with a focus in energy systems, and I am also minoring in mathematics. I first became familiar with CFD through my extensive 3-D modeling work at TCU, and decided to apply for an internship with Pointwise in order to gain a better understanding of all that CFD can help accomplish.

At Pointwise, I have been involved in multiple different support related tasks. We are gearing up for the release of Pointwise V18, which has many great new features, all of which I have had the opportunity to test on Mac, Windows and Linux. I have also worked through all of the revised tutorials which will be included as part of the improved V18 Tutorial Workbook. Additionally, I have been tasked with generating grids for two very complex projects: one for the 2nd AIAA Sonic Boom Prediction Workshop, and the other for the 3rd AIAA CFD High Lift Prediction Workshop. Lastly, I have done some brief scripting in order to help with the testing of some of the new V18 features.

  • Location: Fort Worth, TX
  • Current position: Technical Support Intern
  • Current computer: Apple iMac 27-inch, 32 GB DDR3 RAM, 3.4 Ghz Intel Core i5, NVIDIA GeForce GTX 775M, OS X 10.9.5
  • One word that best describes how you work: Immersed

What software or tools do you use every day?

I use Safari to access the internet. In Safari, I almost always have the YouTrack dashboard pulled up so that I can stay on top of the current bugs and feature requests. Frequently viewing these pages is one of the best ways I have found to learn about and understand Pointwise’s intricacies. Another great set of tools include Pointwise’s User Manual and Tutorial Workbook. These are always open on my desktop for quick reference, and I use Mac OS X’s default PDF viewer, Preview, for this. For keeping track of all my thoughts, I use Apple’s iWork Pages. And of course, I always have a few Pointwise windows open.

What does your workspace look like?

Brody's current workspace.

Brody’s current workspace.

I work in the support area and sit next to Claudio Pita. I often switch between the Mac, Windows, and Linux machines located in our office, so my workspace is really made up of three desks in close proximity to one another. Most often, though, I am working on the iMac machine which I detailed above. Because I keep all of my notes and reference materials on the iMac’s desktop, my workspace is fairly neat and clutter-free, though I do keep some good old fashioned notepads and Pointwise training binders nearby.

What are you currently working on?

I am currently working on refining a grid that I generated from a preliminary geometry as part of the 3rd AIAA CFD High-Lift Prediction Workshop, taking place in June 2017. This project has allowed me to use some of the meshing techniques that I have recently learned, and allowed me to tweak dozens of different settings and parameters, which has given me a better understanding of all the different functionalities that Pointwise offers.

What would you say is your meshing specialty?

Being a relatively new user, I wouldn’t say that I have a specialty just yet. My two major projects thus far have both involved unstructured meshing with anisotropic tetrahedral extrusion, so at this point I would say that I am fairly comfortable with those techniques, and hope to learn as much as I possibly can about them by the time my internship comes to an end.

Any tips for our users?

Pointwise offers a plethora of invaluable resources and reference materials as part of the software. I would highly recommend working through all of the tutorials in the Tutorial Workbook before beginning your own meshing projects, and I would suggest keeping the User Manual nearby and at the ready at all times. Pointwise also offers over one hundred free videos on its YouTube channel detailing various meshing and CFD topics. And lastly, if you ever have any questions, please feel free to contact Pointwise’s technical support crew at support@pointwise.com or 1-800-4PTWISE.

What project are you most proud of and why?

I am most proud of my project for the Sonic Boom Workshop. I have been able to take a complex geometry and make a very nice mesh. This is largely due to Pointwise’s great features and robust functionality, as well as my usage of the Pointwise reference materials and documentation. Due to the complexity of the project and the fact that I am new to Pointwise, I have run into a handful of setbacks, but have been able to get past them using the tools that Pointwise provides, as well as advice from my mentors in the support crew.

A quad-dominant surface mesh on the C25D flow through nacelle test case for the 2nd AIAA Sonic Boom Prediction Workshop.

A quad-dominant surface mesh on the C25D flow through nacelle test case for the 2nd AIAA Sonic Boom Prediction Workshop.

Are you reading any interesting technical papers we should know about?

I am currently reading two somewhat short papers. The first is titled Three-Dimensional CFD Analysis of Semi-Direct Injection Hydraulic Free Piston Engines that comes from a team at the Beijing Institute of Technology. The other comes from the University of Western Ontario and is called CFD Analysis of Convective Heat Transfer from Ground Mounted Solar Panels. It is interesting to see how various topics from my undergraduate studies and my experiences at Pointwise come together to form some really cool research.

What do you do when you’re not generating meshes?

In my free time, I enjoy learning about and practicing app development for iOS devices, as well as being a proud Apple fanboy in general. Being a mechanical engineering major, I do not get to take nearly as many programming courses as I would like, so I taught myself the Objective-C and Swift languages with the end goal of publishing my own app on the App Store by the time I move on from my undergraduate studies. I have found that the hardest part is generating an original and useful idea, so while I feel that I have built up a good foundation, I am still far from completing this goal. I also enjoy messing around with Arduino microcontrollers, and I am currently working on a summer project of building an RC drone (with much help from the internet).

What is some of the best CFD advice you’ve ever received?

Problems can often compound as you go further and further in the meshing process. For each step, it is important to thoroughly examine what you have before moving on. For example, make sure that your database does not have any major flaws or holes in it before adding the connectors and domains associated with that database.

If you had to pick a place to have dinner, where would you go?

My favorite place to eat locally is The Ranch at Las Colinas in Irving, Texas. I highly recommend starting with Queso Blanco as an appetizer, then moving on to the Chicken Fried Steak with Buttermilk Chive Whipped Potatoes for the main course, and lastly finishing with the Pecan Pie for dessert. You will not be disappointed. But when I want something quick, Chipotle is always my first choice.

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3 Short Questions About Your Pointwise Usage

Can you spare a minute to answer 3 short questions about your usage of Pointwise for mesh generation?

Your answers will help guide new product development.

Survey-Button-200x50

Thank you.

 

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This Week in CFD

Software

  • modeFRONTIER 2016 is now available for multidisciplinary simulations.
  • EnSight‘s FAQ for July 2016 includes tips on their calculator and blanked elements.
  • Engineering.com shares some of what’s coming in Polygonica v1.4: new remeshing and point cloud tools.
  • Taking shortcuts on geometry prep can negatively affect your CFD results. ANSYS shares tips on how to prepare geometry for CFD.
  • The KUBRIX mesher is now available as a Rhino-plugin.
  • You can now build boundaries for ANSYS in CAESES.
  • DEVELOP3D delves into COMSOL Multiphysics 5.2.
Example of remeshing in Polygonica v1.4. Image from Engineering.com. See link above. [Note: Not Pokemans.]

Example of remeshing in Polygonica v1.4. Image from Engineering.com. See link above. (Note: Not Pokemans [sic].)

Pointwise User Group Meeting 2016

It’ll be here before you know it. Join us in Fort Worth, Texas on 21-22 September for the Pointwise User Group Meeting.

  • Day 1 is replete with seminars on the latest meshing techniques in Pointwise. Come and sharpen your tool set and consult with our expert engineers. Day 1 ends with a Welcome Reception for all attendees.
  • Day 2 is your opportunity to share your work in CFD using Pointwise, to learn from others doing the same, and hear from us about what’s happening in mesh generation. Day 2 ends with a fun after-party that you won’t want to miss.

pw-ugm-2016-masthead-blue-790x150

Don’t delay; take action today.

Hardware & CAD

  • Quantum HPC, provider of computing resources for CFD and CAE,  launched the Quantum HPC Portal for controlling jobs run on a remote computer.
  • HPCwire seeks nominations for their 2016 reader’s choice awards. Cast your votes by 12 August.
  • You can help Tech Clarity identify how CAD can get better by participating in their Looking at the Future of CAD survey.  Participants get a copy of the survey results and some might even win an Amazon gift card.
Example simulation results from COMSOL Multiphysics 5.2. Image from DEVELOP3D. See link above.

Example simulation results from COMSOL Multiphysics 5.2. Image from DEVELOP3D. See link above.

News

Generating Meshes (Artfully) by Hand

Alert reader Jeff directed me to the artwork of Katy Ann Gilmore whose oeuvre includes captivating drawings like the one below composed of triangles. On her website she explains her interest in the relationship between 2D and its distortion into 3D.

Check out Ms. Gilmore’s work on her Instagram page and on her website where you’ll find works for sale. Her murals are tempting.

I wonder whether she knows she’s meshing?

Artist Katy Ann Gilmore has a unique drawing style.

Artist Katy Ann Gilmore has a unique drawing style.

Bonus: Seems like they’re everywhere.

Yes, this is a Pokemon. Thanks to GrabCAD for the geometry model.

Yes, this is a Pokemon. Thanks to GrabCAD for the geometry model.

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This Is How I Glyph – Helical Connectors

Helical Connector Script

I’m Brian Mack and This Is How I Glyph.

My internship with Pointwise kicked-off this past spring while I was finishing up the spring semester of my junior year at the University of Texas at Arlington. My first assignment was to help a user update an existing Glyph script they had written for use with Gridgen, so that they could continue to leverage it within Pointwise. The script creates a constant-pitch helical connector around any of the three principal axes, and allows users to easily create connectors around a conical or cylindrical object.

The script presents users with a graphical Tk interface where they can specify x-, y-, and z- coordinates for starting and ending points; a principal rotation axis; and a dimension for the resulting connector. The XYZ values for either point can be provided via the available entry fields, or by selecting the point directly from the Display window within Pointwise. Radio buttons are provided, so that users can toggle between the three principal axes to be used for rotation.

Once all of the parameters have been provided, the connector as-defined can be previewed in the Display window by clicking the Create Connector button. The resulting connector’s orientation can be changed, which reverses its starting and ending points. Clicking Apply saves the connector and allows users to continue creating additional helical connectors, while clicking OK will save any connectors created and exit the script. Values entered are retained and can be re-used when creating multiple connectors.  Users can exit the script at any time by clicking Cancel.

To download this script directly, you can use this link. To learn more about this script or contribute changes, visit the project’s repository on GitHub.

If you have an idea for a new Glyph script, and you would like to learn more about how to get started, then contact us via the comments section below or contact @Pointwise on Twitter. We’re also interested in learning more about the Glyph scripts our users have created. Get in touch with us if you would like to share and have your script highlighted here on Another Fine Mesh.

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This Week in CFD

News

Symscape makes the case for wacky CFD. Image from Symscape. Click image for article.

Symscape makes the case for wacky CFD. Image from Symscape. Click image for article.

Software

  • [At the risk of being a jerk], the article 7 Challenges CFD Engineers Face and How They Can be Solved with the Use of Simulation Tools leaves me scratching my head. For example, #3 is Presenting Data to a Non-Technical Audience – which truly is a challenge – mentions “appealing display” and “colours [sic] or contours.” I’ll propose that non-technical consumers of simulation results need to receive data in the same form as any other engineering data; presented as performance maps in the vernacular of the application domain. [Every time this issue comes up I’m reminded of the “machine that goes ping.”]
  • How does cloud-based software address the issues of crashes and data loss? [Can’t we address this on the desktop too?]
  • Beta CAE announced the release of v16.2.1 of their software suite.
  • Frustrum announced the beta of the new Generate software that promises to integrate design and topology optimization.
  • Looking for free, open source, 3D CAD? 3D CAD World lists several options for you.

Applications

Sample simulation of a Jaguar vehicle using Exa's software. Image from imeche.org. See link below.

Sample simulation of a Jaguar vehicle using Exa’s software. Image from imeche.org. See link below.

Structured and Unstructured Art

Serendipity led me to London’s Jessica Carlisle gallery where I found artists exploring both structured and unstructured grid motifs.

Vera Boele-Keimer explores (dis)order, and searches for a balance between stability and fragility – as though she’s generated structured grids before.

Vera Boele Keimer, Woodblock (Blue, Green, Yellow), 2012. Image from Jessica Carlisle Gallery. Click image for source.

Vera Boele Keimer, Woodblock (Blue, Green, Yellow), 2012. Image from Jessica Carlisle Gallery. Click image for source.

Katrina Blannin, on the other hand, goes for the unstructured mesh motif through works that are rule-based (Delaunay?) yet allow her to explore tonal variations that produce visual rhythms. The work shown below looks like it could be a screen shot from Pointwise.

Katrina Blannin, Double Hexad Black Naples, 2013. Image from Jessica Carlisle Gallery. Click image for source.

Katrina Blannin, Double Hexad Black Naples, 2013. Image from Jessica Carlisle Gallery. Click image for source.

Bonus: Alert reader Tessa Uroic found the structured grid below IRL in Porto, Portugal.

Tessa-Uroic-grid-Porto-Portugal

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