Over time, I’ve realized that I’m in this for the adventure. I’m sure you are laughing at that, but it’s true. Discovering and doing mesh generation for me has been one big adventure right from the beginning.
I grew up in the countryside outside the small town of Florence, Mississippi. If you are ever driving through Mississippi, you’ll know you have gone through Florence when you drive past our two competing catfish houses, Berry’s and Jerry’s. Both restaurants sit in iconic buildings, a huge barn and an igloo respectively. Both places make my little hometown stand out and have some of the best fried catfish you’ve ever eaten.
Both my Bachelors and Masters degrees in Aerospace Engineering came from Mississippi State University. While attending MSU, I had many positive influences that mentored me and helped me realize that I wanted to make a career out of computational fluid dynamics (CFD). During my undergraduate and graduate school years, I took all the CFD and grid generation courses offered and had the opportunity to work as a research assistant at the nearby National Science Foundation Engineering Research Center (now known as the SimCenter). The real-world work I did as a student helped cement everything I learned in my coursework and really got me hooked. It was one of the most immersive and effective learning experiences I’ve ever had. I wish that more students could learn about grid generation and CFD in a similar fashion.
After Mississippi State, I began work at Pointwise as a Support Engineer where I was immediately tasked with two daunting jobs. One, become a Gridgen expert in a short period of time. Two, take the one user manual that had been used for previous versions of Gridgen and create three volumes of material: a User Manual detailing every command, a Tutorial Workbook that walks through how to use all the commands, and a Glyph Reference Manual containing the man pages for our scripting language. Porting, rewriting, and improving the Gridgen documentation into a new form quickly helped me achieve my first goal of learning about every Gridgen command in the book (literally). Daily phone calls and emails from our customers – domestic and international – exposed me to all the different application areas and ways in which our customers generated meshes.
I know at this point you may be thinking that this all sounds boring. But for me, I was in love with it. Every single day I came to work and had a new challenge to conquer and a new lesson to learn. I moved on to learn all the other roles that our Support Department engineers fulfill, generating meshes for consulting projects, teaching training classes, designing new features for Pointwise, and performing and managing the quality assurance of our code. Along the way, I also learned a great deal about what it is to work with software and to work with people. Eventually, I took on the role of Manager of the Technical Support Department and I’ve been filling those shoes for the past several years. The thing I love the most about my job at Pointwise is that mesh generation never gets old. I still feel like I get to learn something new, whether it’s from a customer or a coworker, every single day.
- Location: Fort Worth, TX
- Current Position: Manager, Technical Support Department
- Current Computers:
- Dell Precision T3500, Intel Xeon 3.2 GHz, 24 GB RAM, NVIDIA Quadro 4000, Windows 7 64-bit
- Dell Precision T7500, 2x Quad Core Processor,E5640,2.66GHz, 96GB RAM, NVIDIA Quadro 4000, Linux RedHat 5 64-bit
- One word that describes how you work: Enthusiastically
What software or tools do you use every day?
First and foremost I spend a large percentage of my time using Pointwise, both our current production release and our in-house version where we are developing new features. The thing I love about using Pointwise to make meshes is that our team has managed to take all the good things that we did in Gridgen and put them in this new package that makes all the functionality so visible. It’s been done in such a way as to be intuitive to most users. Mesh generation gets a bad rap for being hard to pick up due to the steep learning curve. I personally feel that what we’ve done with Pointwise mitigates that a great deal and take the pain out of making a mesh.
I use Programmer’s Notepad to write Glyph scripts for use in Pointwise. Also all the typical Office products get used on a daily basis (Word, Powerpoint, Excel). I probably shouldn’t admit this but I use Excel a ridiculous amount. You really can make a spreadsheet for everything. Trust me. I use TweetDeck to talk about aerospace and CFD information that interests me and Spark to collaborate with the rest of the Pointwise staff.
Finally, I use SageCRM to monitor and check on our customer sites and their ongoing support. If you’ve ever contacted us for help, you have had a case opened by one of the support engineers here. The cases in Sage allow the entire support team to have access to the problems and/or questions ongoing with our customers. Needless to say this helps us to keep up to date with the current state of the software and to also take over a support case if someone is unexpectedly out for a day. Our goal is to make sure you always get prompt, reliable, helpful support. This tool, along with good teamwork and communication, allow us to meet that goal every day.
What does your workspace look like?
I work in the first floor of our building and have a wonderful office. I sit across a scenic hallway from most of the Support team and I have lots of room for all my computers, notes, and technical papers. I also have a fluffy soft loveseat I dragged in here and shoe-horned in front of my desk. It is a comfy place for my coworkers to park it when we are collaborating in one-on-one meetings. I also have years’ worth of my favorite pieces of Pointwise knickknacks (did you ever see the Gridgen Rubik’s cube or hacky-sack ball?) as well as the odd Star Wars collectible here and there. Last but not least, I have on display my favorite aircraft model of the SR-71 Blackbird.
I had the fortune to bring Robert Gilliland, a Blackbird test pilot, in as a speaker to the Engineering Research Center when I worked there. He was gracious enough to send me this model later on which I have prized for many years.
What are you currently working on?
A lot of everything. It’s good because I enjoy having plenty of meshing projects to keep me busy. On that front, I just finished designing and writing some exciting new features for mixed cell generation which will be implemented in Pointwise Version 18. Some of these features are already partially implemented which means I’m getting to test (ahem, break) them as well. In the course of a normal week, it seems like I’m always making or tweaking meshes for customers but I cannot tell you about most of those due to their sensitive nature.
However, there are a few meshes I’ve made recently that I can share. In October, I generated an unstructured mesh on a Fender Jazzmaster guitar for the International Meshing Roundtable. This mesh along with one made by Claudio Pita and Travis Carrigan for an STL geometry of an abdominal atlas won the 2015 IMR Meshing Contest award.
If you attended our recent Let’s Talk Meshing workshops in Stuttgart, Germany you got to see some meshing I’ve done recently to generate unstructured hexahedra on an automotive intake. The case was an interesting one because there were a couple of different meshing topologies I could have used for the geometry. The topology I decided on had structured domains on the inlet pipes and unstructured domains on the remainder of the geometry where creating structured surface topologies would have been tedious. The entrance to the inlet pipes was a set of O-H structured domains that would be used by adjacent blocks in the grid.
The challenge for most people would be in generating an unstructured boundary layer mesh that matched those structured O-H domains. Since our T-Rex technique (anisotropic tetrahedral extrusion) now supports structured match domains, I simply designated those domains with a T-Rex boundary condition so it would march along them, then set up the rest of the parameters for growing my boundary layer grid. T-Rex marched pyramids and anisotropic tets off the surface grids then transitioned the interior to an isotropic Delaunay mesh. On export, the cells grown off the structured and unstructured domains were converted into hexes and prisms respectively. The entire mesh took less than an hour to construct.
Besides meshing projects, I’ve been working with my support team to plan out our offerings for next year’s training classes. We are all preparing for our first online courses we’ll teach in February and March and working on designing material for new classes beyond that. Additionally, I’m always looking for new ways to teach or explain mesh generation (and Pointwise) so I’m working on a redesign of all our user documentation.
Last, but not least, I’m on the committee for the High Lift Prediction Workshop and contribute grids to that effort. I’ll start work soon on generating initial unstructured grids for the 3rd High Lift Prediction Workshop. If you are unfamiliar with it, I invite you to check out the results from the last workshop.
Every iteration of this workshop I have been involved with has been an excellent learning experience for me. I have had the opportunity to make meshes for a community of people and receive invaluable feedback about what works (and what doesn’t) for a variety of solvers for this application area. The lessons I have learned have directly impacted design decisions I have made for new features in future versions of Pointwise.
What would you say is your meshing specialty?
Unstructured viscous meshing with T-Rex is most definitely my specialty. In 2006 we started working on a technique that allowed us to extrude stacked layers of right-angle tets from a triangular surface mesh. Originally, this came about because we wanted to provide a smooth transition from prism blocks to the isotropic meshes on top of them. Then once the feature was released in 2007, our customers started using it in many different ways. At that point, we realized how powerful the feature could be if we just started directly from a surface mesh on a geometry (instead of an extruded prism block) then converted those stacked tets into prisms instead. We implemented those features into T-Rex as well as collision detection, corner treatment, and sensitivity to various quality metrics. There have been many advancements and improvements to the technique in the ensuing years (hello unstructured hexes!) and the result is meshing style that has allowed me to make large, complex high-quality grids quickly and easily ever since.
Any tips for our users?
Plan your mesh then follow a logical and consistent process to create it. Every time.
As an example, here’s the process I follow for every unstructured mesh I make:
- Review the geometry for cleanliness and geometric complexity.
- Find out what type of flow phenomena the desired mesh is supposed to resolve. If experimental data exists, review it to see the location and structure of the flow mechanisms of interest about the geometry.
- Sketch the topology you’ll need to use for your mesh to capture and resolve flow mechanisms of interest.
- Create a solid model for the geometry to ensure that the geometry is watertight (no holes, gaps, or overlaps).
- Define where surface grids (domains) should be created. We call these topological regions quilts in Pointwise. They are often areas that need to have a specific boundary condition applied later on at export time or they are regions bounded by geometric discontinuities (hard edges).
- Set defaults for grid dimensioning that are in line with the size of mesh you need to create.
- Generate your surface mesh on the solid model automatically.
- Adjust grid spacings on the surface mesh in critical areas.
- Define a farfield mesh and create the definition of the unstructured volume between it and the surface mesh (a block).
- Define the T-Rex parameters for the block and initialize it based on those parameters.
- Review quality metrics for the mesh and adjust the surface mesh or T-Rex parameters as necessary to improve them.
- Once mesh quality is acceptable, set boundary conditions for the desired flow solver and export the mesh to it.
What project are you most proud of and why?
My other answers have probably already answered this question but I would have to say it is my work on the design of T-Rex and some of our other unstructured techniques and features. I’ve spent many hours trying to determine what it is that our customers need in regards to unstructured meshing and how we can meet those needs.
I don’t think any technique is a silver bullet but I feel like with each year that passes we get closer and closer with the additions we continue to make to our unstructured mesh generation tools. I’m proud of having helped move this technology along to its current state. If you haven’t tried it by now, please do. If you ever want to talk about T-Rex or ask questions, I’m always happy to chat with you about it.
What CFD solver and postprocessor do you use most often?
I don’t really do much work with CFD solvers directly. Typically, I will generate meshes in pair with someone running a solver and we’ll provide each other with feedback about what is needed and what was done to meet those needs respectively.
Occasionally, I will fire up OpenFOAM or ANSYS Fluent to check a mesh but I would not say I’m a hardcore user by any means.
Are you reading any interesting technical papers we should know about?
I have a list of papers from this year’s AIAA Aviation conference that I’ve been working my way through. There are two in particular that I’ve been digesting this month. The first one is F-16XL Hybrid Reynolds-Averaged Navier Stokes/Large Eddy Simulation on Unstructured Grids by M. Park, K.S. Abdol-Hamid, and A. Elmiligui. The second paper I’ve been reading is Target-Edge based Orthogonal Anisotropic Mesh Adaptation by J. D. Z. Vasquez and C. F. Ollivier-Gooch. The results obtained by Drs. Vasquez and Ollivier-Gooch were impressive and I look forward to seeing where they take their research next.
Do you plan on attending any conferences or workshops this year?
Since the year is almost over, I’ll talk about the three conferences/workshops I went to this past year.
In June, I went to AIAA Aviation in Dallas, TX where I attended many of the paper sessions and a few meetings as well. There were two sessions which were really the highlights of the conference for me as an attendee. The first was a special session on historically significant/influential papers in applied aerodynamics featuring talks by R. Liebeck, P. Spalart, and A. Jameson. Each presentation was packed with people and I think we all enjoyed hearing about these seminal papers and the research behind them. The second highlight of the conference was the special session on the Future of Fluids: Next Generation CFD. There were many insights shared by some of the leaders in our field on how they think we will get CFD to the next level.
In October, I had the opportunity to go to the 2015 VINAS Users Group Meeting in Tokyo, Japan. VINAS distributes our software in Japan and has a large conference each year where the users of all the software they distribute gather for presentations and workshops. On the last day of the conference, I taught a T-Rex workshop for our Japanese users.
In November, we did our first Let’s Talk Meshing Workshop in Stuttgart, Germany, where I did a seminar on creating unstructured hexahedra with T-Rex in an automotive intake manifold.
What do you do when you are not generating meshes?
Most of my spare time is spent with my husband and our 10-month old baby boy. He’s constantly learning about the world around him and we are enjoying seeing the world through his eyes. From the joy of playing in an empty box to discovering the fun crinkle of leaves in his hands, he reminds us every day not to take the small things for granted.
When I’m not babying, I like to indulge in my passion for photography. I have a Nikon DSLR and an array of different fun lenses I cart around. A year or two ago I took some courses from a local university and learned the basics. Since then I have been taking every opportunity I get to photograph landscapes, portraits, action shots, etc. It’s a fun hobby and, at this point, simply requires a great deal of hard drive space for all my experimentation.
Many of my other hobbies are shared with my husband. We love to work together and have mutual interests in woodworking, car restoration, and barbeque. In our garage, we’ve assembled a collection of power tools that we periodically use to recreate some piece of furniture we saw in a store or on Pinterest. Beside our garage I have my grandfather’s 1964 Comet that we are very slowly working on restoring. On the barbeque front, my husband makes phenomenal brisket and ribs in his reverse flow smoker while I enjoy cooking hawgs for friends and family.
What is some of the best CFD advice you’ve ever received?
When problems arise in your mesh, look at the foundation of the mesh first.
The connectors and domains in each grid have a huge influence on the quality of the associated volume cells. Do you have a connector with an undesirable distribution of grid points? If so, that’s going to bleed into the quality of the associated domains and blocks. Do you have a domain with sliver triangles or highly skewed quads? The associated block will also have similar issues. Resolve problems at the foundation first and the quality of the volume cells will follow suit.
If you had to pick a place to have dinner, where would you go?
It’s hard to pick just one place. I love good food of all types. If you were looking for some tasty beef barbeque, I would have to tell you go to my favorite spot in town, Cousin’s. If you are in the mood for a mind-blowing burger, go to Lili’s and have their house burger smothered in gorgonzola. For a nice romantic Italian dinner, Piola’s is my favorite hands-down. It’s in a tiny little house near West 7th and has a great atmosphere. As a foodie, one thing that I love about Fort Worth is the selection of restaurants we have in town and the quality of the food. It’s hard to go wrong with any place you pick. Come, visit, eat and enjoy Cowtown!