NRG Excitations
Published in

NRG Excitations

NRG at the 11th US National Combustion Meeting!

Note: I first drafted this story in April 2019… nine months ago! Yikes! It’s been languishing as a draft and overdue for publishing. Sorry about that! –KN

NRG members Anthony, Morgan, Kyle, Jayani, AJ, and Paige in front of Space Shuttle Endeavour at the California Science Center, during the banquet of the 11th US National Combustion Meeting (photo credit: AJ Fillo).

Last week (March 30 through April 3) six members of the Niemeyer Research Group traveled to Pasadena, CA, to attend and participate in the 11th US National Combustion Meeting. Kyle flew, because he had to be there early Saturday morning for an early-career researcher workshop—more below!—and AJ, Morgan, Paige, Jayani, and Anthony all drove down from Corvallis.

I asked each of them to either call out a particular talk they found interesting or write a bit about their talk (for Morgan and AJ). Their responses follow, and I talk about the presentation I gave below that.

Paige: I enjoyed the talk by Z. LaBry on flame thickening with the Damköhler In-Situ Targeted Adaptive Numerical Thermochemistry (DISTANT) model. This model was used to relax areas of high stiffness for LES modeling of turbulent, unsteady reacting flows.

Anthony: A talk that was particularly interesting to me was a study of wind effects on the structure of a turbulent line fire. Specifically, I found this interesting because it demonstrated how the different modes of heat transfer effected fire spread.” This talk was by Salman Verma and Arnaud Trouvé of the University of Maryland.

Jayani: The paper ‘A comparative study of moisture evaporation models in the drying and pyrolysis of moist solid fuels’ caught my attention because this is a computational study done using the Gpyro software. The objective of their work is to improve the modeling of evaporation in Gpyro. Gpyro by default uses Arrhenius equation to model evaporation. The authors have incorporated the equilibrium model into Gpyro using the operator-splitting technique. They have discussed the pros and cons of both methods and concluded that Equilibrium model better represents moisture evaporation.

Morgan about to present her talk in the Chemical Kinetics section.

Morgan gave a talk on her honors-thesis research in the Chemical Kinetics section. She presented a comparison of several predictive models for toluene autoignition. Toluene, or C₆H₅CH₃, plays a major role in predictive modelling of practical fuels such as jet fuel, gasoline, and diesel. The comparison was done using openly-available software (PyTeCK) and published experimental data from combustion experiments, which were converted and openly shared. The study compared 11 models using 175 experimental data points collected from five published experimental studies. In addition to the performance comparison, she analyzed ignition delay and overall performance to reveal influential chemical reactions in a high-performing model from CalTech. Community research efforts can be focused through reaction-specific model analyses. Morgan also attended several other talks mostly in the Chemical Kinetics section and was interested in hearing more about fundamental combustion experiments.

AJ also gave a talk in the Turbulent Flames section, on a new portion of his PhD research. He wrote a bit about his overall research focus, and the topic of his presentation:

As engineers we can use numerical simulation, or virtual models of flames, to better understand combustion physics at a fundamental level. However, as cool as virtual flame simulations may sound they can be very difficult and expensive to generate. To help alleviate these challenges and make flame simulations more accessible, combustion engineers have used simplifying assumptions to make the fundamental mathematics easier to solve. The trouble is we still need to confirm that these assumptions are valid and can accurately reproducing the true physics of the flame we simulate. That’s where I step in. As a combustion engineer I study the “models” we use in numerical simulations to verify that they are as accurate as we need them to be. If a “model” isn’t good enough I work to develop an improved model to replace it improving the overall accuracy of our simulated flames.

So why do we care? These simplifying “models” are often used to run large simulations of things like jet engines which directly influence the engine designs we ultimately build and fly through the air. As a result, it’s critical that our assumptions are as close to true physics as possible to ensure the real world engines we build work as intended. In that vein, we’ve recently found several places where we need to improve the “models” we use to simulate flames and have developed a new more accurate tool which can affordably replicate the true physics of a flame and replace the older less accurate approach. My presentation at the US National Combustion Meeting was a first step in convincing fellow researchers to stop using the old “model” and adopt our new and improved option. Our hope is that our fellow engineers will begin to use our new tool to improve the accuracy of their simulations to improve our understanding of combustion physics as a whole.

Screenshot of the talk I gave: “A review of evidence-based best practices in developing research software in combustion”
The full slides for the talk I gave are available openly under the CC-BY license at

I gave a slightly different talk, called “A review of evidence-based best practices for developing research software in combustion”; I coauthored this along with my colleagues Ray Speth, Bryan Weber, and Richard West. Rather than focus on a combustion topic, this focused on best practices we recommend researchers follow when they develop software for their research.

These practices include sharing your work openly, writing good documentation, using (modern) version control practices, automating testing of your code, having peers review code, and citing software in articles. I also talked about why we think—and evidence suggests—that these are good things to do.

The talk was reasonably well attended, but those who did attend had great questions and feedback—this is definitely a topic folks in our research community want to hear about, and one we will certainly return to.

Participants of the 2019 Combustion Early Career Investigator Workshop on Caltech’s campus, after completing our workshop discussions and peer mentoring. We’re joined by what appears to be the nose cone of a rocket (but what is actually, and perhaps disappointingly, just a light).

Before the conference began, I attended a workshop for early career folks working in the combustion and fire research fields (and some related areas). In academia, “early career” generally means someone without permanent tenure and in their first non-temporary position, or an equivalent starting position at a national laboratory.

We talked about a variety of topics, including outreach, cross-diciplinary work and open science, mentoring, and education. Overall it was a fun and productive meeting, building on a similar workshop we ran in 2017.

I helped organize parts of the event, along with Nicole Labbe of CU Boulder, but the workshop was really led by Jacqueline O’Connor of Penn State and Richard West of Northeastern, and they deserve most of the credit for its success.

Thanks to the organizations that supported our travel to this conference—and the work we presented!—including the National Science Foundation (grants 1535065 and 1733968), Strategic Environmental Research and Development Program (SERDP), NASA (grant NNX15AU66A), and Oregon State University.



Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store