Setting Fire to CIS - or- Small Scale Combustion Chamber and Instrumentation Dave Pogorzala Bob Kremens, PhD, Advisor Center For Imaging Science Rochester Institute of Technology

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory history project goals research methods results conclusions / future work overview:

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory the Forest Fire Imaging Experimental System (FIRES) team traveled to the Fire Sciences Lab (FSL) in Missoula, Montana during the summer of ’01. there they used a large combustion chamber to image several fires with the ASD, an IR Radiation Pyrometer, and a visible / IR camera history:

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory we want to be able to image fire at any time construct a small-scale, self standing combustion chamber - what features from the FSL facility are needed? allow the chamber to be tailored to other specific uses - Adam and Jim’s project - work to be done this summer test the chamber - does it hold up to a full-fledged fire? - will the instruments be able to image the fire? project goals:

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory combustion chamber facility at the FSL Burn surface Smoke hood Instruments Bryce

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory project goals: find fire’s emissivity - emissivity- the ratio of the radiance emitted by an object at a certain temperature to the radiance by a perfect blackbody at that same temperature - “We definitely need, at a minimum, the emissivity and temperature profiles of the flames to model a fire with DIRSIG” - Bob Kremens - come to a conclusive value that could be published

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory research methods: chamber design initial design was simplified - research was done on flume dynamics - no need for smoke hood and fan - burn surface can be simulated with an outdoor grill - camera ports were made square - easier to modify their size

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory research methods: data acquisition both instruments had to be interfaced with the computer -developed thermocouple data logging program in VB -used preexisting program with the pyrometer thermocouplepyrometer

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory experimental setup

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory combustion chamber facility at CIS

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory Flux (W/cm 2 ) =  *  * T 4 pyrometer thermocouples calculated emissivity research methods: calculating the emissivity unfortunately, it was not this easy the Steffan-Boltzmann Law

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory both instruments yielded temperature data - thermocouples measured actual temperature of the flame - pyrometer interpreted detected radiance as temperature assuming an emissivity of 1.0 emissivity was found using a look up table research methods: calculating the emissivity but it still wasn’t this easy

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory the pyrometer’s rise time coefficient is < 1 sec the thermocouple’s rise time is ~ 45sec in order to correlate the two sets of data, a Fourier analysis had to be done on the pyrometer data - frequencies above 1/45 cyc/sec were removed resulting pyrometer data was more “stable” research methods: calculating the emissivity

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory temperature vs. time

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory temperature was read from the new pyrometer data ( ) this was used to find the fire’s radiance;  =1.0 ( ) this radiance was found at the fire’s actual temp ( ) the union of the pyrometer’s radiance and the thermocouple’s temperature yielded the emissivity ( ) research methods: calculating the emissivity

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory a set of 12 individual samples in time gave an average emissivity of H. P. Telisin (1973)* measured emissivity under various weather and fuel conditions, resulting in a range of 0.1 – 0.58 results:

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory this figure of can be trusted, but will be verified by additional testing this summer add up to 5 more thermocouples to simultaneously monitor the fire in various locations - do temperature variations give different emissivities? collect data on different species of wood - different chemical compositions could yield their own emissivities automate the LUT process in IDL conclusions / future work:

R.I.TR.I.TR.I.TR.I.T R.I.TR.I.TR.I.TR.I.T Digital Imaging and Remote Sensing Laboratory Bob Kremens, PhD Don Latham - Project Leader, Fire Sciences Lab, Missoula, MT Al Simone * Telisin, H. P. 1973, “Flame radiation as a mechanism of fire spread in forests”, In: Heat Transfer in Flames, Vol. 2. (N.H. Afgan and J.M. Beer, eds.), John Wiley, New York acknowledgments: