My foray into CFD began in the fall semester of 2006. Technically, I had been a Computational Engineering student at the University of Tennessee at Chattanooga’s SimCenter since the spring semester; but to that point I had only taken a couple of sophomore engineering courses (because I had a math background) and a linear algebra course I was all but qualified to teach (since I was already a mathematics professor at the community college up the road). So, Dr. Steve Karman’s Grid Generation course was my first “real” SimCenter course and I was woefully unprepared. The course was heavy with programming assignments. I could compile “Hello World” and that was about it. I distinctly remember needing to look up the syntax for a “for” loop while coding the first assignment. But nine years and about 25,000 lines of code later, I managed to graduate with a Ph.D.
I was privileged to have a strong grid education under the tutelage of Steve Karman. In many such engineering programs, gridding is an afterthought at best and a necessary evil at worst. But Steve is a dedicated grid researcher who attracted lots of students, including me. After his departure for Pointwise, it has fallen to me to mentor the remaining grid research students at the SimCenter, including Kristen Karman Shoemake, Steve’s daughter and former Pointwise intern.
But my real job nowadays is the Algorithms Engineer for Branch Technology, a large-scale 3D printing company. By “large-scale” I mean we 3D print large objects for construction and art. The objects in question are, in fact, nothing more than meshes which is where I come in. As a consultant and now as a full-time employee, my job at Branch has been to develop algorithms that take meshes and turn them into code for our unique extrusion process.
Pointwise plays a critical role in this process. All our creations start as a mesh in Pointwise. The meshes are output and processed by custom code that I and our co-founder have written to create path motions for the robots that perform the extrusion. In many ways, it’s much like the CFD process of mesh creation to solver, only our solver is a two-ton robot.
Location: Chattanooga, TN
Current position: Algorithms | Optimization Engineer, Branch Technology
Current computer: MacBook Pro, 2.6 GHz Intel Core i7, 16GB Ram
One word that best describes how you work: Purposefully
What software or tools do you use every day?
Pointwise, of course. The wall and furniture won’t grid themselves. Besides that, I spend a lot of time coding in Visual Studio as well as in a plugin for Rhino called Grasshopper. These are the tools we use to control the robot.
What does your workspace look like?
Branch is a startup so we have furniture scrounged from all over. My desk was broken and headed for the dumpster before we found it.
What would you say is your meshing specialty?
The obvious answer is tetrahedral meshing since that was my dissertation topic. However, what I do well is getting a good mesh for whatever application is in front of me by whatever means necessary. That often means hacking together the capabilities of several pieces of software (Pointwise, SolidWorks, in-house codes, etc.) to get what is needed right now. That was true during my time at the SimCenter and is true now that I’m at Branch…only now I’m the one who wrote some of the codes I’m hacking together.
What are you currently working on?
Right now we are concentrating on small projects like furniture, so I’m putting a lot of meshes on tables created by our designer. Also, we are starting an overhaul of our algorithms and processes so I’m spending a lot of time writing code.
What projects are you most proud of and why?
At Branch Technology, I’m very proud of the work we’ve done to translate structured meshes into actual objects. This work has taken a lot of thought and coding. From my last job at the SimCenter, I’m probably most proud of the work we did analyzing drag-reduction devices on transfer trucks. It’s very easy to point out side-skirts and base-flaps while passing a big rig and say “I helped analyze those things.”
Any tips for our users?
At the SimCenter, there were several things I always hammered into students about Pointwise. First, save early and save often. Lots of work is being put into a mesh so don’t let a power outage or a glitch in Pointwise set you back hours. Second, the layer manager is your friend. Too many times I’ve seen people just put everything in the first layer which quickly becomes cumbersome. Finally, make sure the tolerances and model size are set properly at the beginning of your process. I’ve been bitten by not doing that several times.
What CFD solver and postprocessor do you use most often?
Are you reading any interesting technical papers we should know about?
Yes. Over the past year I’ve been investigating possible methods to build unstructured grids with our robots. The most promising method so far is one my boss found in a paper entitled FrameFab: Robotic Fabrication of Frame Shapes by Huang et al. (Full citation here.) It presents some very good ideas about how to fabricate any unstructured mesh and even cites our website.
What do you do when you’re not generating meshes?
I am a blessed man with a full life. That is another way of saying I have a lot on my plate. Outside of work, I have a wife and two school-age children. I am also a deacon at our church. Finally, I have a very active game group full of life-long friends that meets about every other week.
Do you plan on attending any conferences or workshops this year?
Nothing overly technical, but I will be attending a local design conference sponsored by one of our plastics suppliers, TechmerPM, called SHYFT. Last year, SHYFT featured Jay Roger of Local Motors fame. This year my boss, Platt Boyd, is one the invited speakers.
What is some of the best CFD advice you’ve ever received?
I was privileged to be educated by some great CFD engineers, not the least of which is the aforementioned Dr. Steve Karman. Steve would always tell us “You cannot solve what you do not resolve.” Another great piece of advice that sticks with me came from Dr. Timothy Swafford. Swaff would say, “There’s nothing more dangerous than answers that look about right.” True in CFD, true in life.
If you had to pick a place to have dinner, where would you go?
That’s a hard question for two reasons. One, I’m not very picky and not much of a foodie so my advice is suspect. Two, there are so many good restaurants in Chattanooga that it can be a little overwhelming. Putting aside even the high-end chains likes Ruth’s Chris, which I love, we have lots of quality restaurants like St. John’s, 212 Market, and Public House. Even so, I would probably choose something like Champy’s, a fantastic local fried chicken joint, or the Bluegrass Grill which has awesome breakfast.