Kristopher Overholt » School

Grassland fire research at The University of Texas at Austin

koverholt — Mon, 11 Apr 2011 06:54:03 +0000

While a large number of wildland fires are burning through West Texas and threatening the safety of life and property of Texans, the fire research group at The University of Texas at Austin is actively working with physics-based computer models and laboratory-scale fire tests to characterize the fuel properties and flame spread characteristics of grassland fuels.

Computer model of grassland fire simulation

At UT Austin, we have been performing small-scale, controlled experiments in our burn structure to determine ignition times and burning rates for grassland fuels as well as intermediate-scale, controlled experiments to determine the fuel and combustion properties of grass fuels, the effects of external wind on ember production, and the heat release rates of grass bunches.

Controlled grass fire test in the UT Austin burn structure

We can utilize the results of the small- and intermediate-scale experiments in full-scale computer simulations of grassland fires using modeling tools such as Wildland-urban interface Fire Dynamics Simulator (WFDS).

Using the results and methods from these controlled experiments along with the help of the wildland fire community, we plan to develop a framework to determine fuel properties of wildland fuels, predict the physics and fire dynamics behavior of wildland fires, and achieve safer conditions for people and property faced with the threat of wildland fire situations.

Inverse fire modeling for heat release rate characterization

koverholt — Wed, 23 Mar 2011 16:51:48 +0000

Attached are my PDF slides on the topic of “Inverse fire modeling for heat release rate characterization“, which was presented at the 7th US National Combustion Meeting in Atlanta, GA on March 21, 2011.

The abstract is as follows:

A ubiquitous source of uncertainty in fire modeling is the proper heat release rate for the fuel packages of interest. An inverse heat release rate (HRR) calculation method is presented to determine a HRR that satisfies measured temperature data. The methodology is developed by using synthetic temperature data using the Consolidated Model of Fire and Smoke Transport (CFAST) zone model to produce hot gas layer temperatures in a single compartment. The inverse HRR method runs at super-real-time speeds while calculating an inverse HRR solution that can reasonably well match the original HRR curve. Examples of the inverse HRR method are demonstrated by using a multiple step HRR case, experimental data with a constant HRR, and complex HRR curves. In principle, the methodology can be applied using any reasonably accurate fire model to invert for the HRR.

The slides can be downloaded here: Overholt_Combustion_2011

Plotting data on videos – A useful way to convey qualitative and quantitive information

koverholt — Wed, 25 Nov 2009 08:49:44 +0000

Every once in a while, someone makes an impression on you that lasts for a lifetime. It sticks with you every single time. This is one of those, although a bit on the nerdy side, it is one that can change the way you present information in a very meaningful way.

I was once sitting at the NIST annual fire conference, going about my business, and someone working on a project regarding the structural response aspect of buildings on fire showed a video in their presentation. No big deal, right? Normally, we get cool fire videos, then some plots, and so on. Sometimes the plots are interesting, sometimes they are default from Excel with the ugly legend and all – with no story to tell.

But not this guy. He showed a video with real-time plots superimposed over the video showing the exact real-time structural response of the structure overlaid on the video in a plot. “AMAZING!” I thought. And it stuck with me. A useful way to convey synchronous information. People love videos, why not tell the qualitative AND quantitative story at the same time?

So I started working in grad. school on fire problems, and naturally, soon thereafter, I was scheduled to give a presentation. As most of my real creative coding and writing work happens of hours between the hours of 1 AM and 6 AM, I wanted to make this happen. I REALLY wanted some real-time plotting action in my presentation. No Excel templates for me! So I stayed up for a couple nights and worked on a way to use MATLAB to make this plotting dream a reality: I worked on importing videos, messing with frame rates, tons of images, and so forth. And soon thereafter, it happened. I had a working script.

I used it to show plots of large-scale fire tests with actual and predicted flame heights vs. time as seen here:

And I used the script to show the predicted flame heights on a small-scale test in an amazing way that just about anyone can relate to, fire-crazed scientist or not:

From anyone who has seen the videos firsthand, the response has been amazing. This is a great teaching and communication tool, and surprisingly enough, I haven’t found any existing program or tool that does this. And so I am sharing the videos and script here for anyone to use to better convey information.

My next steps are: 1) to convert the script to Python (since I am now almost exclusively using Python+numpy+scipy for my graduate research and daily work instead of MATLAB, and 2) to make the script into a cross-platform and easy to use tool.

I’m providing the code in its raw and uncommented and unedited form. It generates a number of images with plots superimposed on them, and then it is trivial to use a program to stitch them together into a video. I used Quicktime’s built in method. Sorry, too much current work going on finishing my MS thesis and Master’s degree to clean up the code, but it’s a brutal use of the “release early, release often” ideal! Hopefully someone can make some use of it.

So, here are the linked .m files:

http://www.koverholt.com/scripts/ssPlotVideo.m
http://www.koverholt.com/scripts/fireplotVideo.m

Enjoy! And please leave your comments or ideas!

The cold wind is here

koverholt — Sat, 06 Dec 2008 00:26:07 +0000

Here comes this weather that is very foreign to me!

A good day was had talking with the president of a big conglomerate corporation and tons of cheese. Tim Ferriss totally has it down with talking to big CEOs, they are like the hot chicks of the business and job world – i.e. everyone is afraid to talk to them straight and never does, therefore they love to have some informal talk with you and wil remember you always. Also, free beer on campus is cool (hooray private schools without state school regulations)!

Which reminds me, I used to have this statement written in a marker right above my bed when I would wake up in the morning: “Your intention creates your reality.” And I have it on my fridge now. Same idea. It’s true, eh.

Two years ago I quit my job to follow my dream, and each day it gets better and better. It’s amazing what the human mind can do with the help of God. This is exactly what I wanted and there is so much more good to come.

An excellent time was had here as well with my mom visiting Worcester for a week:

And Katie came to visit for a different week as well. We all had a blast here with deliciously cheap happy-hour seafood, bone-chilling temperatures, bland Dominican food in Massachusetts, nuns racing through the park, endless drives along the cliffy coast, and just plain being together. It had been a few months since I saw Katie, and it made it that much better. Many good times were had and many more million to come.

15 days ’til I return to the big Texas. I really miss the people, but not so much the place.

I guess Texas is the home of my heart and Massachusetts is the home of my brain. The two can coexist in harmony you know:

Humorous happenings from the WPI Police Log

koverholt — Wed, 19 Nov 2008 00:26:00 +0000

Everyone enjoys the stories from police logs, ranging from loose chickens in some towns to even sillier things in others. Sure, crime is serious, but thanks to making police logs public, much humor is to be found. Here are a few of my favorites fom the WPI campus police log.

Saturday, November 8, 2:04 am: Male on Boynton St. who appears to be intoxicated. (Hmm, checks timestamp, yep, got ‘em!)

Saturday, November 8, 3:17 pm: Officer speaks to young kids skateboarding in the East Hall parking garage, advising them to move along. (Classic, need I say more?)

Sunday, November 8, 12:02 am: Caller reports group of students playing with fire in a can in West St. parking lot. Officer dispatched, individuals advised. (Advised of what? The joys of playing with fire?! It wasn’t me I swear!)

Sunday, November 9, 1:00 am: Pumpkin thrown at SNAP van from balcony on West St. Officers check, find smashed pumpkin, no people on balcony. (Pumpkin taken into custody.)

Sunday, November 9, 1:53 am: Caller reports female playing music and singing out of her window in Founders. Female is very loud and keeping students awake. Officer dispatched, locates student; singer advised to be mindful of other students. (Ahh, I was hoping he would join in! We need more public singing!)

Sunday, November 9, 3:27 pm: Feces found on floor of Morgan Hall restroom. Custodian en route. (It is the only room with a drain.)

Tuesday, November 11, 2:10 am: Caller reports having vomited in Stoddard A. (What a nice guy; classy. Would love to hear the call.)

And there you have a window into my world at WPI. Leaping pumpkins, public singers, and bodily fluids fill the police log. Now laugh along with me, lest you be advised to move along, you damn kids!

The Arrival of Collaboration in Fire Protection Engineering

koverholt — Tue, 21 Oct 2008 05:42:15 +0000

Earlier today, the professor for my Combustion class mentioned that for our final project, we will be working on a problem that currently has no solution. This intrigued me of course, as I wondered if our final grades would have no solution as well. After he explained, it made all the more sense and reminded me why my love and passion is in the field of fire protection engineering, the school I go to, and the people I work with: they all heavily align with my values and principles of sharing knowledge and making information available to everyone, everywhere.

[From NASA]

So, let me explain his model simply by example:

The professor said that when he first started this class 2 years ago, the students were working on a different problem with no solution… at the time. The class worked together and in the end the results were so significant that a couple of students took the initiative to publish the results in a scientific journal. The same happened when the class was taught last year – project done, paper published.

So what does this mean and why do you care? Well, all too often in the academic world, people can get caught up in working on projects and sort of work themselves into a dark corner where nobody gets to benefit from the results… and this is done in real life as well, not just academics. This is where the ridiculous amount of collaborative technology available to us comes in to play. Want to gather up notes on the Smagorinsky constant and publish them for anyone to find who is searching for them in the next 1000 years? Easy: 5 minutes. Want to publish your results in the most useful way? Easy: work on an open source project in your area along with your research – or make your own.

…Or you could write a paper, finish your thesis work, wrap up the loose ends in a few years and show a flashy poster of your work 5 years after anybody cares about it anymore or thinks it to be useful.

I digress. I just wanted to stress this new method of collaboration that is among us, and how it’s going to change the way that we work together and grow together in fire protection engineering and fire science.

[From Rowan University College of Engineering]

Why not make use of motivated students and brainpower when they come together? Here is me welcoming this new phase of community and collaboration in a field that directly impacts life safety and makes safer buildings around the world. So when we work on that final project in a few weeks, it’s not really at all about a grade anymore – it’s about a new way of doing science – together.

Update: This is exactly the kind of stuff that I’m talking about here, posted today on the SFPE National blog that I set up a year ago – collaboration: Foundation Funded Research underway at WPI

Passionate and Artful Communication in Science

koverholt — Thu, 25 Sep 2008 06:46:00 +0000

So there are scientists, and there are artful scientists. Here’s version 0.9999 of the graph from my last post in all of its full and smooth glory. It’s for a homework exercise in my combustion course (go ahead, click for full size – it’s fantastic):

Well, why do you care about my graph? I certainly do. There are many books about conveying information in statistics and how to present data in a very informationally dense format, sure. But let’s think about this graph that I made for a homework assignment. The purpose of the homework was for me to learn, yes? And that nice orange line bought me some extra credit worth 25 points, but that’s another story. I want to learn it inside out, run it amongst others, and in the end communicate great things to many, many people. Every time. With every action.

So I could have left the default Excel settings for the chart, but my soul cannot allow such a thing.

This graph shows relationships, it runs a conversation with itself and lets the numbers drive by each other and say hello. It’s living, and it talks to me. Check out the dark red diamond line called “Mixture Fraction”. This guy drives all of the others. Then the f’s come in. Then we go back to the real quantities like the mass fraction of oxygen (Yo) and fuel (Yf) and we can also grab temperature (in Kelvin) based off of what those f’s are telling each other.

Yes, yes, Kris. You are talking nonsense, I don’t like it. Well, perhaps I’m not as eloquent and direct as this guy (watch this great motivating video, do I ever let you down?):

But our messages are the same. Do what you love, and work your ass off at it. All the time. Not the old and dead cliched way of “do what you love” – but the minute by minute, day by day, just got home tired from work but I need more, but I don’t have the time, wake up and do it, it keeps you up and night, but I want to watch TV every day, what you REALLY want to do, an exact thing/action/pursuit every day until you die – kind of way.

If I wasn’t here loving my graphs at 2:34 AM in the morning and pondering the million things I just learned from this 4 day exercise, I’d quit. If I doubted for a second (as the guy in the video says), I’d do us all a favor and leave here. But I want this knowledge, and these relationships so very badly. And when the end-result comes along, I have a sick urge to spend so much time and detail on things so that others may benefit. Make your life, thoughts, and business public, and see what happens to it. It skyrockets.

Now do you see why I care about my graph? I’m proud of what it represents. Now go off and care about your own graph. For the rest of us.

Why Do I Chase Fire? (and video)

koverholt — Mon, 01 Sep 2008 05:27:50 +0000

Three fire engines and a ladder truck just blared by my house going southbound on the street and stopped about two blocks away. What a beautiful sound of the QO2 siren screaming by on a chilly city night. It takes me back to a few years ago, hearing the fire dispatch alert going out, gearing up in seconds at the station with 45 pounds of firefighter bunker gear, and peeking around each street corner as the truck leaned away from the turn – not knowing if there would be a small car fire or a huge commercial building fire. Terrified people waiting with nobody left to turn to as their family members are endangered by the power of fire. Their life history, photo albums, accomplishments, and material possessions having flames licked at them and could be vaporized into an ashtray within only a minute.

That blaring sound is why I do what I do. And people ask me, why do I like this field so much? Fire is mesmerizing, fire is better understood each day that passes by, but still greatly misunderstood. Fire is extremely useful. Fire is extremely devastating. Fire has context to define its will.

To me, understanding the dynamics of a fire dancing and licking around can be like trying to understand the psychology of billions of different humans. It can be like trying to catch something running away by using differential equations and fluid dynamics. It can be like painting a picture for hours or days and the end product is something that sticks with you every day for the rest of time.

It is like playing on a sports team and working with your family when working in the lab. We work for 3 hours on setting up temperature sensors and calorimeters and even more hours discussing and brainstorming in a room boiling over with a mental flood of science, passion, logic, deduction, and induction. All about fire. Then we burn our creation in 1.73 minutes and forever destroy it, releasing yet another drop in the endless pool of ongoing knowledge.

Here is a video that exhibits a very successful test burn from today. The box is filled with small plastic cups and packed like one that would be shipped. We set up instruments inside to measure the fire size, temperature inside at different places, cameras to record the flame standoff distance, and a ton of other information.

I guess in my version of 1984, things make sense in this way: fire is knowledge, community is power, and intuition is freedom.

This is why I do what I do.

First Lab Fire Test at WPI

koverholt — Tue, 26 Aug 2008 06:18:33 +0000

Ohgod, ohgod, ohgod. My first day working in the fire laboratory at school and about 30 minutes into it this is what I get. Why am I so excited about fire? Fire!

The day started off cool enough with French combustion students presenting their projects done at WPI.

Just watch:

The test involves measuring the heat energy from the flame, tracking the flame as it spreads inside the box, and the mass loss rate of the box throughout the burn. The purpose of the test is to better classify the types of hazardous storage commodities and much more greater things than I can put into words.

As the lab student said today, “As much as we like to protect people from fire, we also really like to burn stuff.”

Fire. I love this place. Nerds, community, really motivated people. And fire.

What an intense day. My brain hurts, time for sleep.

2,000 Miles Nearby

koverholt — Fri, 22 Aug 2008 22:32:01 +0000

I haven’t updated the blog in a bit since I didn’t have actual internet for a while there, but all is exceptional here in Worcester, MA.

I’m outside in the setting sun in my makeshift office in the 60 degree weather in mid-August. And as Eetion would say about my temperature preference, I’m right at home. As Brenda would say about my mind and soul, welcome home. As Marcos would say about my outdoor adventures and motorcycling, I’m in a great place. And as Katie would say about my craziness and passion, I’m in my element. And as my mother would say, I’m too far away.

Everyone has had a huge impact on my transition, from my sick grandmother’s prayers from a very long way away to some new found friends at WPI to the greatly helpful faculty at school.

Hopefully friends and family can come and join me soon while I follow the trails of my passion in this weird and pleasurable experience and location.

You can see the entire photo albums here: the 4-day trip up here and the first day in Massachusetts doing high-pointing in New England.

Thank you to everyone and I will see you soon. Look for some exciting updates to come with my new found Internet connection.

And as always: peace, love, and happiness to all.