The t-squared fire ramp calculator is available here:

http://www.koverholt.com/t-squared-fire-ramp-calculator/

Please let me know if you find any bugs, would like to give feedback on this tool, or have a request for another web calculator!

Related posts:

1. New web calculator tool – transient steel heating under fire conditions
2. New web calculator – flame heights and plume centerline temperatures
3. Inverse fire modeling for heat release rate characterization

This guide will help you compile the CFAST executable on Mac OS X and Linux. This is useful for running CFAST cases on Mac or Linux machines, which is especially useful for scripting CFAST runs for optimization problems or running CFAST on a large number of cases in batch mode.

You will need the Intel Fortran compilers (ifort) and a copy of the CFAST source code from the CFAST Google Code site. You can try to use other free compilers, but I find that the Intel compilers are the most compatible and produce the most optimized (fastest) binaries. Note: there are heavily discounted Intel compilers for students.

To download the CFAST source code, the easiest way is to install subversion on your Mac or Linux machine and issue the following command:

svn co http://cfast.googlecode.com/svn/trunk/ cfast

Once you have the CFAST source code on your machine, you can perform the following steps to compile the CFAST executable.

1. In the cfast/CFAST/ directory, edit the makefile_linux file and make the following changes:

• Replace ‘radation’ with ‘radiation’; this is a typo
• Add ‘cyl_conduct.o’, ‘datamodules.o’, and ‘ssHeaders.f’ to the obj_serial section
• Add the following lines to the Object Dependencies section:
• cyl_conduct.o : cyl_conduct.f
• datamodules.o : datamodules.f90
• ssHeaders.o : ssHeaders.f
• Add ‘cyl_conduct.f’, ‘datamodules.f90′, and ‘ssHeaders.f’ to the cfast.o line

Note: The corrected makefile can also be downloaded from here.

2. Copy datamodules.f90 from the cfast/CFAST/Include/ directory to the cfast/CFAST/Source/ directory

3. Change to the cfast/CFAST/Source/ directory

4. Run the command ‘ifort -c datamodules.f90′ to compile the datamodules and iofiles modules

5. Finally, run the command ‘make -f ../makefile_linux intel_osx_64’ to build CFAST

5b. If you are running Linux, the command is ‘make -f ../makefile_linux intel_linux’

Using these steps, I was able to build CFAST on an Intel Macbook Pro running 10.6 (Snow Leopard) as well as a Linux machine running CentOS release 5.6 with the 64-bit Intel Fortran Compiler version 12.0.4.184.

Related posts:

1. Mac-Corrected Numerical Analysis Fortran Programs
2. How to install PyObjC, pygame, and gasp on Mac OS X for Python tutorial

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.

Related posts:

1. Poster for Cardboard B-number Research
2. Inverse fire modeling for heat release rate characterization
3. Buying a Burning

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

Related posts:

1. The Arrival of Collaboration in Fire Protection Engineering
2. Grassland fire research at The University of Texas at Austin
3. New web calculator tool – transient steel heating under fire conditions

http://www.koverholt.com/flame-height-and-plume-centerline-temperature-calculator/

Please let me know if you find any bugs, would like to give feedback on this tool, or have a request for another web calculator!

Related posts:

1. New web calculator tool – transient steel heating under fire conditions
2. New web calculator – t-squared fire ramp generator
3. Plotting data on videos – A useful way to convey qualitative and quantitive information

http://www.koverholt.com/transient-steel-heating-under-fire-conditions/

I hope you find the calculator useful, and I will continue to add web tools for fire protection engineering calculations. I will be adding a more detailed explanation and equations to the steel heating calculator page in the near future as well as releasing the source code.

Please let me know if you find any bugs, would like to give feedback on this tool, or have a request for another web calculator! The next web tool will be a calculator to give results from the Heskestad flame height and centerline temperatures.

Related posts:

1. New web calculator – flame heights and plume centerline temperatures
2. New web calculator – t-squared fire ramp generator
3. Plotting data on videos – A useful way to convey qualitative and quantitive information

I came across this copy of a report (from the IAFSS mailing list) which details a report of a cooking fire turned explosive when the sprinklers were activated. Allegedly the propylene glycol used in the fire sprinkler system as an antifreeze aided in the explosive event, and another case is cited in which the antifreeze ignited and assisted in growing the fire from its ignition source.

The report can be found here: California –explosion– report (PDF)

While I have taken a few courses in fire sprinkler systems, I am not extremely familiar with the flammability of antifreeze such as propylene glycol, but allegedly the atomization of the droplets causing the liquid to become flammable was the cause of this explosion. More flammability and MSDS hazard info is cited in the report.

The report presents many questions at the end which would be useful in quantifying the relationship of the antifreeze in this case, especially since (to my understanding) propylene glycol is the most widely used antifreeze in sprinkler systems. I look forward to finding out more about this topic, and I think it’d be a great research project for a student or research firm to take on.

Related posts:

1. The human element in fire protection engineering

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!

Related posts:

1. New web calculator – flame heights and plume centerline temperatures
2. Passionate and Artful Communication in Science
3. New web calculator tool – transient steel heating under fire conditions

They were all events linked to arson and serve to show us the complicated relationship man has with fire, even with the modern day engineering tools and cutting edge analysis methods available to us.

Let me explore these three events in more detail:

Jesusita Fire; May 2009; Santa Barbara, CA

In May of 2009, a 300 foot high wall of fire burning through Santa Barbara, CA had 30,000 people running out of their city and wondering what they would return to, if anything more than an ashtray of their home’s contents. 3,700 acres were burned and it was marked as the most threatening natural disaster in the history of Santa Barbara. The cause? A campfire that got out of control from nearby marijuana growers.

40 MPH winds served to spread the fire as fast as it could towards the city. At the end of it all, 78 homes were destroyed, 29 firefighters were injured, and 15.5 million dollars were used. All from a campfire. From pot growers. This event reeks seriously of the complicated relationship between humans and fire – a relationship of utility, usefulness, crime, chaos, and control. A relationship that cannot be engineered out by even the best computational fluid dynamics code in the world.

Gallery Furniture Fire; May 2009; Houston, TX

Moving from wildland fires to warehouse fires: in May of 2009, an iconic Houston furniture warehouse burned to the ground as freeway traffic crawled by with worried onlookers in the late evening hours. After a long night of fighting the fire, the 100,000 square foot Gallery Furniture warehouse was no more and fell victim to to the 4-alarm fire. The Bureau of Alcohol, Tobacco, and Firearms stepped in and ruled the fire as arson, leading to the arrest of an employee who worked at the furniture store.

This fire hits me close to home since my Master’s thesis research involves warehouse storage and commodity fire protection and how it can be improved. I can formulate the best mathematical fire spread model for predicting fire spread along cardboard stacked to the ceiling, but will my math model account for a crazed man dumping gallons of gasoline in the warehouse and firing up a match? Absolutely not.

Willingham Residential Fire; Dec. 1991; Corsicana, TX

This last fire I’ll discuss was a residential fire in the city of Corsicana in Texas. In December of 1991, the home of Cameron Willingham was burned and his three children were killed in the fire. He was later arrested and imprisoned on the basis that he had set fire to his house and was responsible for the death of his children. The fire marshal’s investigative report backed this up. 12 years passed, and Cameron was executed in February of 2004 in Texas for murder charges.

Just a few days ago, in August of 2009, a report from Craig Beyler at Hughes Associates (one of many reports to check the validity of the fire investigations on Willingham’s residence) stated that the fire investigation seemed more like the work of psychics and mystics rather than scientific work. There are other human factors here at work – Cameron’s alleged abuse of his children is one example – but I am sticking to the discussion of the relationship between Cameron, the investigators, and fire. In the report, Beyler stated that the investigators had a poor understanding of fire science. And because of their poor understanding, a man was wrongly killed by the state.

Putting it all together: Humans, fire, and education

So the relationship of man vs. fire goes back to the first time someone discovered fire. It is very complicated. Now what? How can we use our understanding of this relationship to save lives?

While churning along my research path, I have learned that I favor fire research, fire dynamics, and fire forensics over alarm design, building construction work, or working with fire codes. The three fires that I discussed above are most interesting to me are all involving arson in some way – and humans in a big way. One fire came from clumsiness, one fire stemmed from passionate and crazed anger, and one fire put to death a wrongly accused person and killed three children. I don’t know about you, but to me, this serves to smack us fire protection engineers in the face with a reminder that the human element can never be ignored, or fully engineered out of the problem of fire. The consideration of the human element should be included in every thought, design, and fire model that is churned out.

And although a recent survey by the Society of Fire Protection Engineers showed that most people think that fire is the greatest likely event to cause harm to them, it also showed that only 18% of the respondents actually worried about the dangers of fire more than once a year. The solutions that fire protection engineering provides stem from years and years of exploring this relationship of people and fire: how crowds react in a building fire, how different residential occupants can be awoken in a fire, and how people respond to building fire alarms.

In my opinion, the best help in the impact of fire protection engineering is effective education of the public. Informing the public (in interesting and engaging ways!) about fire safety and what they can do in their homes and workplaces to stay safe. Informing college students about dorm fire safety. Moving on from stop, drop, and roll, and giving people more of the information and knowledge that they deserve. Informing residents about the benefits of fire sprinklers, and having a huge incentive to have them installed, even retroactively.

And who is responsible for all of these education efforts? Anyone and everyone in the fire protection field. From engineer to firefighter, fire librarian to professor, code official to fire marshal. Everyone can serve to help the big picture of educating the public by taking fire science courses, by working with code committees, by linking together agencies and people who need to be talking, but aren’t. Fire investigators can take fire science courses and fire scientists can run into burning buildings in training exercises. The more we know as professionals about the big picture, the more we can help and educate the public, and save lives in the process.

So again, I say that effective education of the public is the best tool in fire protection engineering. Because without an informed public, we can have the best fire models and investigators in the world, but we would only be putting a band-aid on the complex fire hose of man vs. fire.

Related posts:

1. The Arrival of Collaboration in Fire Protection Engineering
2. On the Topic of Human Touch
3. Why Do I Chase Fire? (and video)

The letters are a fantastic look into how humans interact with fire and how the human mind can develop such an exotic relationship with something like fire – even in a fetishistic way. From one of the letters:

Why did I set the fires when I set them? That’s an all too familiar question that can not be understood if you don’t know the story. There were different reasons for most of the fires. It could be because of one feeling the need to have power about something or someone….I don’t want you driving that car so the fire becomes a weapon to destroy it.

Or in case of some house fires—I might like a particular style of a house and wish one day to own it (but it’s only a dream). Fire is a tool to destroy and some house fires also becomes my phantasy of people scrambling to exit windows and sort-of feel like they need my help so I stay and watch.

Fire destroys things, kills people, moves people in cars, keeps people warm, cooks people’s food, lights things, lifts planes, and on and on. Our relationship with fire is an oddly philosophical one.

After doing for so long it just became easier and easier but the fear of getting caught was always there. Each fire was like doing the first time and I’d always take deep breaths and ask the Lord to forgive me for what I’m about to do…

Sweatt was sexually driven to set these fires and received great erotic pleasure from watching the houses burn and the people escape for the sake of their lives. He constantly states that his intentions were not to harm the people, although he acknowledges that fire is “risky business”.

[...] it was her grandson that led me back to that house later that night only because I didn’t know him personnaly but saw him get the mail out of the mailbox on the front porch and he was tall and has a muscular build and I wanted to meet him so I would live out my phantasy thru fire watching him jump out of the window for help and come running to me. I raced home to watch the news and was sadden about the fatality but was fascinated by this huge fire. Wow! I’ll always remember this house.

My passion in fire protection engineering involves chasing the trails of fire – any clues or physically meaningful signatures that fire gives off – and characterizing them in a scientific sense. It’s very intriguing to break down fire into thousands of different smaller actions and facets.

At the same time, I realize that there is some ingrained mental pleasure that humans get from fire – some understood relationship. Sweatt led the Bureau of Alcohol, Tobacco, and Firearms on a long chase as he developed his dangerously passionate love for fire.

Give the article a read when you have some extra time – it will take about an hour. You will get quite a bit of insight into the madness and intricacy of the human mind and fire. And how they work together in ways both good and bad. It was how Sweatt expressed himself in seeking pleasure.

Some people use guns, knives, etc. as weapons—I use fire as a source of weapon—Not afraid of fire at all; for it is my friend and I miss it. [...]

Now, this arsonist, Sweatt, took it to an extreme and caused 2 deaths, destroyed many homes, used up countless hours of fire service resources, and permanently affected the lives of many, many people. At least 353 fires. How does he feel today?

There was only 1 death, he wrote, so I left it at that.

[...] Those demons are still in me.

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