Laminar Flame Studies (Sponsor: NASA) PI: S.S. Krishnan, Department of Mechanical Engineering, IUPUI

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1 Measurement and Diagnostics Laminar Flame Studies (Sponsor: NASA) PI: S.S. Krishnan, Department of Mechanical Engineering, IUPUI

2 Laminar Flame Studies Combustion and Propulsion Research Laboratory Why? -Future missions to the moon and Mars -Need to understand fire (with high O 2 ) behavior in space environments. What did we do? Courtesy: NASA Press Release Studied the effect of oxygen enhancement, inverse flame configuration and gravity on: Flame shapes, Total and Spectral radiation properties. How did we do it? - Flame images 6.1 MPix. digital SLR camera (Nikon D100), - Radiative heat flux distributions and total radiative heat loss - Radiometer (Medtherm 64P-I-22) - Spectral radiation emission - Fast Infrared Array Spectrometer (2.5 4µm) What kind of flames were studied? Laminar Normal Diffusion Flames (NDFs) and Inverse Diffusion Flames (IDFs) (of C 2 H 6 with the O 2 mole fractions in the oxidizer varying from 21% to 100%).

3 Laminar Flame Studies Combustion and Propulsion Research Laboratory What were the Conclusions? Analytical results of flame shapes compared favorably with experimental results. 1 g Inverse Flames g 30 mm c R (%) Total radiative heat flux all these flames can be estimated using single-point radiation heat flux measurements fairly accurately. Trends of χ R (radiative heat loss fraction) are significantly different for Normal vs Inverse Flames. mg 21i 30i 50i 100i Q f (W) Spectral emission measurements reveal the presence of H 2 O, CO 2 and soot. Low-temperature unoxidized soot in Inverse flames and CO in high O 2 Normal Flames and all Inverse Flames Flame IDF100B ; 100% O2 ; Qf = 803 W ; Re = 362 ; Lf,blue = 37.5 mm x / Lf,blue = 1.1 x / Lf,blue = 1.1 r / x = 0 r / x = 0.1

4 Capabilities Combustion Diagnostics Facility at the Combustion and Propulsion Laboratory (IUPUI, Indianapolis, IN) The plexiglass housing and the vibration-isolated optical bench have been used in the past to measure spectral emission from and for highresolution digital imaging of laminar flames. Motorized x-z stages and high-speed data acquisition capabilities and graduate student researchers will allow for quick and efficient testing. An unsteady combustion code called UNICORN developed by Innovative Scientific Solutions Inc. and Air Force Research Laboratory is being used to simulate the experimental results and obtain detailed flame structure effects on these flames.

5 Potential Applications Combustion Diagnostics Facility at the Combustion and Propulsion Laboratory (IUPUI, Indianapolis, IN) 1. Burner Emissions Characterization: This facility can be used to study small commercial burners (such as used in residential furnaces) to obtain information on combustion products (H 2 O, CO 2, hydrocarbons and soot) emission from high-speed, high resolution spectral measurements. A computational evaluation can be performed using UNICORN. 2. Exhaust Emissions Characterization: This facility can be used to study exhaust gas and particulate emission from diesel-fired heaters, internal combustion engines etc. with some modifications. 3. Fundamental Studies related to Soot and other Particulate Characterization: This facility can be used to study soot and other particulate sizing and aggregation characterization with some funding from the National Science Foundation (NSF) or the Environmental Protection Agency (EPA).

6 Acknowledgments The laminar flame studies were made possible through a National Aeronautics and Space Administration (NASA) grant and through equipment support from Purdue University, West Lafayette. Thesis students: Jason M. Abshire (MSME, 2004) Manish K. Saini* (MSME (Purdue), 2006) *Manish Saini tragically passed away in an automobile accident recently. He is remembered posthumously for his enthusiasm, dedication and hardwork during this study.