I’m Travis Carrigan and This Is How I Mesh

Travis Carrigan, Senior Engineer on the Sales & Marketing team.

Travis Carrigan, Senior Engineer on the Sales & Marketing team.

Have you ever been to the Idaho Potato Museum? If not, you should go. They’ll give you a free potato at the end of the tour…or at least they used to. I’ve been there several times. The museum sits in my hometown of Blackfoot, Idaho.

It was back home where I became a pilot and where I spent all my free time bumming around the local airport working on airplanes. Next, I moved to Arlington, Texas where I ended up studying Aerospace Engineering at The University of Texas at Arlington. Before receiving my bachelor’s degree in 2009, I worked as a Quality Assurance Engineer on the Boeing 787 program at Vought Aircraft. The following spring, as I wrapped up my junior year, I was offered an internship at Pointwise on the Technical Support team. I took it immediately.

I spent my first summer at Pointwise working with Carolyn Woeber, the manager of our support team. At the time I was responsible for the functional testing of Gridgen and one of the earlier releases of Pointwise. During the summer I learned enough about grid generation to be productive and knew that I’d be doing CFD from then on.

After receiving my bachelor’s degree I started my second internship at Pointwise, this time on the Sales & Marketing team as an applications engineer working with Chris Sideroff. Chris now distributes and supports our software in Canada. I meshed, and meshed, and meshed, every day, all day, all summer. In just a few months I had generated meshes for geometries in nearly every application area where we have a customer. I was hooked.

I continued working as an intern at Pointwise throughout graduate school. During that time I was working mornings at Pointwise, taking a full course load in the afternoons at UTA, and spending my nights in the CFD lab performing vertical axis wind turbine design optimization. As an intern at that time I helped support the sales process and generated content for webinars, videos, and articles. Most of my original work is still floating around our website.

Just before I wrapped up my master’s degree in Aerospace Engineering at UTA in 2011, I was offered a full time position with Pointwise as a Senior Engineer on the Sales & Marketing team. Since then I’ve been heavily involved in the production of our technical marketing content and sales process.

My primary area of responsibility is new sales. In order to sell our software, I work closely with prospective customers to help strengthen their CFD process by introducing them to Pointwise. Often an engineer will contact us with a meshing problem and it’s my responsibility to determine if Pointwise is the right fit for their application and help them discover the solution throughout a fully supported evaluation. This is a very technical process and one where I’m always learning about new CFD applications and challenges.

  • Location: Fort Worth, TX
  • Current position: Senior Engineer, Sales & Marketing
  • Current computer: Razer Blade, Intel Core i7-4720HQ Quad-Core 2.6GHz, 16GB DDR3 RAM, 512GB SSD, NVIDIA GeForce GTX 970M, QHD+ 3200×1800 pixels, Windows 8.1
  • One word that best describes how you work: Wholeheartedly

What software or tools do you use every day?

I live in Outlook. Supporting everyone who is thinking about evaluating Pointwise and those currently working an evaluation means I’m reaching out to potential customers, working with system administrators on installation, fielding technical questions with engineers, and discussing terms and prices with buyers. I work hard to achieve inbox zero by the end of the day because that means I was able to help everyone who reached out to me.

Google Chrome is my window into all our online and web accessible content. I use Chrome to access and manage our Glyph script exchange on GitHub. Throughout the day I’ll look for any Pointwise or meshing questions that arrive via CFD Online. I use TweetDeck to monitor various feeds and tweet events and other CFD related content. Our YouTube page is where we host all our video content and I’m actively uploading new videos and responding to comments. We use YouTrack to log feature requests and bugs in our software, so I keep an eye on that and log any requests that come from discussions with any clients I’m working with. Our internal wiki provides a ton of useful information and is where we work with our developers to define the requirements for new features. I’m currently working on a couple new feature requirements that I can’t wait to share with you! But most of my time spent in Chrome is working with Sage CRM, our customer relationship management software where I track all incoming evaluation requests, quotation requests, and those evaluating the software.

Throughout the day I’ll use Pidgin to chat with my coworkers. A quick message can save a phone call or an email. I use vim when writing or editing Glyph scripts and Cygwin to access my remote Linux workstation to run CFD calculations or generate large meshes. The Microsoft Office suite of tools such as Word, Excel, and PowerPoint, no matter how hard I try to find alternatives, keep me productive. I record a lot of videos including webinars, in-depth meshing videos, and tutorials for #TutorialTuesday. Camtasia makes it easy to capture my screen so I can produce content and get it online quickly. And it goes without saying, but I use Pointwise every single day.

There are two more tools I use that I couldn’t do my job without: GoToMeeting and the phone. GoToMeeting has become such an important part of my job that I can’t imagine working without it. When someone would like to see Pointwise in action, or show me something they’re working on and get feedback, in about a minute I can have a meeting up and running. Often one GoToMeeting session will save an entire day’s worth of email, and I can record it and send it to the client. The phone is similar in that a single phone call can save time, it’s more personal, and allows us to escape the computer for a few minutes.

What does your workspace look like?

Travis's current workspace.

Travis’s current workspace.

I’ve moved around our building a lot. I worked in two different conference rooms during my internships, spent a summer in our server room running CFD calculations, worked for about a year in a corner, then an office, and now a corner office. I have a great view of downtown Fort Worth, three large desks, a couple bookshelves, and a plant.

I like to make wherever I’m working comfortable, and by that I mean cluttered with little gizmos and fun stuff. I’ve amassed a small collection of bobble heads against my will and a few really nice aircraft models. Some of the more fun stuff sits on my desk. The Useless Machine provides a lot of entertainment and they have a great return policy—if you don’t find it completely useless, return it for a full refund. Last year I assembled the Strandbeest kit by Gakken and it’s earned a permanent place on my desk. My wife is a Research Scientist at the University of Texas at Arlington’s Research Institute (UTARI) and works in the Biomedical Technologies group. While working on a project involving casting, she made a cast of her hand, which she painted green, and which I stole and proudly display on my desk. I get a kick out of the awkward stares when customers drop by to chat. My wife is very creative and has contributed a number of laser cut wood models to my collection.

What are you currently working on?

A lot of things. I get anxious when I’m not working, so I always have something to do. Most of the work I do is in support of those evaluating Pointwise. I can’t reveal specifics, but what I can say is that during any given week I could be meshing an automotive geometry, a full aircraft, a turbine blade, writing a Glyph script to automate part or all of a meshing process, making a video to demonstrate a particular feature or workflow, or running a CFD calculation to validate a particular meshing strategy. When someone commits to an evaluation, I’m 100% all in to help them discover Pointwise and offer the same level of support they can expect once they become a customer.

Lately I’ve been working on the DrivAer, a realistic external automotive geometry proposed by the Institute of Aerodynamics and Fluid Mechanics at the Technische Universität München. Often automotive geometry is extremely complex, and the DrivAer is no different with over 15,000 unique surfaces. Working with others in this industry I’ve found that a lot of engineers use discrete automotive models (STLs) and meshing algorithms that are tuned for surface wrapping. The difficulty with this approach is that discrete geometry can degrade accuracy and lacks the topological information that analytic models can provide. However, to take advantage of analytic models coming from CAD requires geometry cleanup and robust meshing strategies. Our goal with this project has been to demonstrate such strategies and best practices for cleaning complex analytic CAD often encountered in the automotive industry and automatically generate boundary layer resolved grids. The project has been successful and we’ll be presenting this work coupled with shape deformation and optimization at the 10th OpenFOAM Workshop.

Hybrid volume mesh for the DrivAer geometry colored by element volume.

Hybrid volume mesh for the DrivAer geometry colored by element volume.

I’ve been involved with our webinars and videos since we started producing them back in 2010. I began by producing only the technical content, then drove the software while others presented, and now I organize and produce our webinars with a customer and/or a software partner. Pointwise webinars give people the opportunity to see the software being used in the real world and for many different applications. At the moment I’m working on our next webinar which will go live later this summer. I’m also involved in producing short tutorials in a segment we call #TutorialTuesdays on YouTube and Twitter, along with longer videos that demonstrate the entire meshing process.

What would you say is your meshing specialty?

As I’ve mentioned, one of my roles is pre-sales support during the evaluation stage. Therefore, I must be well versed in our software and best practices so I can help new users get up to speed quickly. That being said, I’d say my meshing specialty is unstructured viscous meshing using T-Rex.

Having worked many different meshing applications over the last few years I’ve come to appreciate the intricacies of getting something rather automated to do what I need it to do for a complex geometry. I know how T-Rex works, I know how and when to apply it, and I know how to get it to do what I want. The secret is all in the surface mesh.

Any tips for our users?

If you’re stuck, contact us. Zach already mentioned it in his post, but I’ll reiterate. Don’t hesitate to contact us if you have a question, comment, or concern. Believe it or not, we love hearing from you. The more feedback the better! We are your grid generation subject matter experts and are available to help in any way we can. Feel free to contact us by phone (1-800-4PTWISE), email (support@pointwise.com), the web, or request a GoToMeeting invitation.

It’s probably scriptable. Glyph scripting is a powerful tool. It gives you access to every command in the Pointwise user interface. However, unlike in the GUI, with Glyph you can string together multiple commands and write your own macros and features. I call this hacking Pointwise since you can get the software to do some pretty incredible things like solving a Rubik’s Cube or playing Pong. A more productive application would involve splitting multiple connectors simultaneously. In Pointwise you would have to split one connector at a time. Another great application is taking a connector, copying, translating, and then stretching it to fit between two points. These three separate tasks can be combined into a single script.

T-Rex is all about the surface mesh. The quality of a volume mesh is highly dependent on the quality of the surface mesh. Keep in mind that when running T-Rex you are advancing elements off of the surface mesh. If your surface mesh quality is poor, the volume mesh will also be poor. So if you encounter a poor quality element in the volume, look at the surface mesh in the vicinity. Not always, but more often than not there is a spacing or something else not set correctly on the surface. Below are my recommendations before generating a volume mesh using T-Rex.

  1. Select all the domains on the surface of your geometry (exclude match domains) and examine the area ratio. The area ratio should be less than 4 everywhere. If you find you have a high area ratio, chances are there is a spacing mismatch at a node. When advancing elements off the surface, smaller elements will reach isotropy (T-Rex stop criteria) sooner than larger elements. This means that if you have a large area ratio you have a small element adjacent to a large element and when advancing into the volume mesh the front could stop prematurely.
  2. With the surface domains still selected, examine the maximum included angle. Keep this as low as possible. Geometry is going to dictate this, so high angles may not be avoidable all the time. I like to keep my max angle less than 150. If I have an element that’s higher than that I’ll decide whether I need to modify the surface mesh in that region either by joining domains, or by approximating the geometry to eliminate the poor angle.
  3. Assuming you haven’t assembled the block yet, take your grid into Grid, Merge and ensure you have no lamina connectors. Lamina connectors on the interior of your grid indicate gaps in the surface mesh and should be fixed or else a watertight volume cannot be generated.

What project are you most proud of and why?

It’s a tie between two Glyph scripting projects. I began working on the first project just before I was hired full time. It was a project for a Quiet Aircraft Technology program member and I worked with Nick Wyman to automate the meshing for conical and chevron jet nozzles. The Glyph scripts we wrote automatically generated overset, multiblock structured grids given an input nozzle geometry. We developed a user interface for each script that exposed all the meshing parameters necessary to generate the grids from scratch so the end-user wouldn’t have to load up the Pointwise GUI. Once the grid had been generated, the script would export all the component grids and PEGASUS control file used for the overset grid assembly. Acoustic simulations were performed, requiring the grids to be of very high quality. To give you an idea how much time this saved the engineers, assembling a single grid by hand would take one to three days depending on the complexity of the nozzle. The script reduced that to under an hour.

Graphical user interface for the jet nozzle overset meshing Glyph script.

Graphical user interface for the jet nozzle overset meshing Glyph script.

The second project was a Glyph scripting library I wrote to elevate the order of linear elements generated using Pointwise. Using the grid coordinate enumerator written in Glyph by David Garlisch, a Senior Engineer on our Product Development team, I was able to gain access to the grid model, compute the nodal locations for the additional points including placing them on the CAD geometry where appropriate, and generate the higher order connectivity for each element. The script was successfully coupled with a script generated by Cameron, Compression Systems that automatically generated multiblock structured finite element grids for open-faced centrifugal impellers. In the end we had a set of automated tools for generating higher order hexahedral grids to improve the prediction of centrifugal impeller failure modes.

The inducer view of the centrifugal impeller illustrates the use of quadratic hexahedral elements. This mesh was generated automatically.

The inducer view of the centrifugal impeller illustrates the use of quadratic hexahedral elements. This mesh was generated automatically.

What CFD solver and postprocessor do you use most often?

When I need to validate a meshing strategy for a particular application or when I’m working on a project that requires I run a calculation, I rely on a few open source CFD solvers. I’m primarily using OpenFOAM on my Linux workstation for incompressible, steady and unsteady simulations. I’ve been using OpenFOAM for more than five years now and worked with David Garlisch to develop a plugin so Pointwise users can seamlessly export a grid to OpenFOAM without the need to run any additional meshing utilities.

Recently I’ve been using Caelus, a restructured derivative of OpenFOAM that runs on my Windows machine. Because it was forked from OpenFOAM, it’s an environment I’m comfortable working in. That being said, under the covers Caelus is different. Solvers are only included if they’ve been validated against published data, the turbulence models and wall functions have been rewritten, and a number of library enhancements have been made including updated interpolation and gradient schemes.

I’m also using SU2, an open source CFD solver developed out of Stanford University. I have SU2 running on both my Windows machine and my Linux workstation and primarily use it for external aerodynamics calculations. Over the past couple years we’ve done a lot of work with the SU2 team. Last year we hosted a webinar and discussed supersonic aircraft shape design using the Lockheed Martin 1021, a test case from the AIAA Sonic Boom Prediction Workshop. As part of the project I wrote a Glyph script to generate free form deformation boxes and export the data to SU2 for shape deformation. A few months later we held a joint workshop at Stanford where we walked through the entire CFD process using Pointwise and SU2.

For postprocessing I use a mix of ParaView, EnSight by CEI, and Tecplot. My OpenFOAM environment is setup to load results directly into ParaView, and I’m using both EnSight and Tecplot for grid visualization and solution visualization. Our first joint webinar was hosted by Tecplot and we discussed an automated methodology for optimizing the aerodynamic performance of vertical axis wind turbine rotors, my master’s work. We’ve hosted a couple webinars with CEI. One involved North American Eagle and an attempt to break the land speed record, another with CRAFT Tech and analysis of cavitation and acoustics of a water injection pump.

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

A few. I’m reading John Steinbrenner’s Construction of Prism and Hex Layers from Anisotropic Tetrahedra which describes T-Rex and more specifically the evolution of cell combination techniques. I’m also reading Aeroacoustic Simulations of a Nose Landing Gear using FUN3D on Pointwise Unstructured Grids by V.N. Vatsa, M.R. Khorrami, J. Rhoads, and D.P. Lockard. Both papers will be presented at AIAA Aviation. While working on the DrivAer grids and simulations I’ve been reading Experimental and Numerical Investigation of the DrivAer Model by A.I. Heft, T. Indinger, and N.A. Adams.

Recently I had the opportunity to attend one of Edward Tufte’s courses on Presenting Data and Information. John Chawner recently wrote an article describing a few of the highlights. After taking the course I started reading Beautiful Evidence. It’s a great book and I especially enjoyed the chapters on sparklines and the fundamental principles of analytical design.

Do you plan on attending any conferences or workshops this year?

Absolutely! This month alone I’ll be at three different conferences and workshops. June 15th-19th I’ll be in Montreal at TurboExpo. Please drop by the booth and we can chat about your turbomachinery meshing applications. The following week I’ll be at AIAA Aviation. Be sure to attend our Let’s Talk Meshing Workshop on June 21st before the conference. You’ll learn how to use our latest overset meshing tools, get an introduction to Suggar++, see some new Pointwise features, I’ll be teaching you how to get started with Glyph scripting, and our president will present the product roadmap for Pointwise. You won’t want to miss it. The week after Aviation I’ll be in Ann Arbor, Michigan at the 10th OpenFOAM Workshop. There I’ll be presenting our work on the DrivAer automotive model. Come by and I’ll show you how Pointwise seamlessly integrates with OpenFOAM. The last week of July I’ll be in Orlando, Florida at the AIAA Propulsion and Energy conference.

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

Sleep.

Just kidding. I have a lot of different hobbies from running CFD on a Raspberry Pi to building a home flight simulator. After graduate school I started reading again and am a big fan of Daniel Suarez and his books. Right now I’m reading Beautiful Evidence by Edward Tufte, To Sell Is Human by Daniel H. Pink, The Everything Store by Brad Stone, and IT by Stephen King.

I do a lot of gaming on iOS, Android, PC, and the PS4. A few years ago I fell into indie gaming and discovered a unique world of art I never knew existed. I could recommend a dozen or more great indie titles, but anything by Amanita Design is absolutely perfect. Samorost, Machinarium, and Botanicula will leave you speechless.

Something else I discovered by chance was coffee. Those who know me know I’m coffee crazy. I’ve amassed a collection of more than ten different coffee makers, all manual brewers with different filtering mechanics. I could go on all day about coffee and the science and art of brewing but I won’t. Instead all I’ll tell you is that real coffee doesn’t taste like Starbucks or a K-cup. A real cup of coffee brewed properly will highlight flavors you never knew existed. Imagine drinking a cup of coffee so sweet that you don’t need to add sugar and so smooth that milk and cream are no longer necessary. The Hario V60 is the most natural way to brew a cup of coffee and gives you control of the brew ratio, grind size, water temperature, bloom time, and brew time. If you want to learn more you can visit my blog. Unfortunately it hasn’t been updated in a while, but there’s plenty of great content.

Few of my hobbies would be fun without someone to share them with. My wife’s a great sport and supportive of everything I do. The two of us do everything together and have recently taken up fishing near our home. She’s a phenomenal cook, a great travel companion, and my best friend. When I’m not generating meshes I’m spending time with her, sipping a coffee and relaxing.

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

“All models are wrong, but some are useful.” –George E. P. Box

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

My wife and I love to eat and try new restaurants wherever we go. Here in Fort Worth, Texas I would recommend Rodeo Goat for the best burger in DFW. If I were back home in Blackfoot, Idaho it would be Rupes. Be sure to try the fry sauce. In San Antonio, Texas I’d say Boudro’s on the Riverwalk. Seattle, Washington would be Elliott’s Oyster House, probably the best seafood place I’ve been to. In San Jose, California you’ve got to drop by Pizza Antica on Santana Row and when you’re finished walk across the street to the Tesla shop just for fun. In New York City definitely Xi’an Famous Foods for some authentic Chinese. If you’re in Albany, New York be sure to try Dave’s Gourmet & Exotic Burgers. It’s the only burger place I know of that sells a python, camel, and kangaroo burger. And lastly, when in Montreal you must visit Le Gourmand Restaurant.

About Travis Carrigan

A Pointwise engineer helping other engineers solve their meshing problems.
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6 Responses to I’m Travis Carrigan and This Is How I Mesh

  1. Pingback: Meshing the airship's hull -- CFD Online Discussion Forums

  2. Pingback: I’m Rick Matus and This Is How I Mesh | Another Fine Mesh

  3. Pingback: Mesh Morphing for Automotive Shape Design Optimization | Another Fine Mesh

  4. Pingback: I’m John Chawner and This Is How I Mesh | Another Fine Mesh

  5. Pingback: I’m John Stone and This Is How I Mesh | Another Fine Mesh

  6. Pingback: I’m Luiz Fernando Silva and This Is How I Mesh | Another Fine Mesh

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