KCFP Södertälje May 8, 2008 Optical methods for combustion research Mattias Richter Associate Professor Division of Combustion, Sweden Tolvan Tolvansson, 2007 Johannes Lindén, Division of Combustion
Chemiluminescence Photographs What is optical diagnostics Utilization of electromagnetic radiation (light) for the purpose of measuring or visualizing certain properties High-speed video recordings Spectroscopic studies Measurements, e.g. EGR, Temperature Black-body radiation IR- pyrometry Laser induced radiation LIF, LIP, LII Raman scattering Rayleigh scattering Bunch of other techniques
What can optical diagnostics do in engines? Species distributions / concentrations LIF Absorption Raman / Rayleigh Chemiluminescence Flow PIV LDA / LDV /PDA Tagging techniques Temperature LIF CARS (Raman) Rayleigh Absorption spectroscopy Mixture preparation Spray penetration Spray angles Evaporation Fuel/Air mixing Combustion characteristics Ignition events Flame propagation Flame quenching Knock centers Low / High temperature regions Causes of misfires Pollutant formation NOx Soot Unburnt HC
Is it a playground? What was this man doing in 1876? Nicolaus Otto presented the four-stroke engine Otto s try-out engine engine displacement bore * stroke cooling power rated speed weight one-cylinder 6107 cm³ year 1876 161 * 300 mm water (usage) 2 kw (3 HP) 180 1/min around 1500 kg
Is it a playground? What was this man doing in 1872? Nicolaus Otto developed his prototype using optical engines
The industry is (was) definitely using it Rassweiler & Withrow, GM 1930 s by using a large quartz window extending across the entire combustion chamber and using high-speed motion picture film, we could photograph the entire burning process from the moment of ignition to its completion. "This insight into the mysteries of combustion helped clarify the knock problem. From the book: The future is our assignment, GM, 1959. Tolvan Tolvansson, 2007 Johannes Lindén, Division of Combustion
KCFP Södertälje May 8, 2008 The industry is definitely using it Tolvan Tolvansson, 2007 Johannes Lindén, Division of Combustion
Large bore gas engine Study of the Early Flame Development in a Spark-Ignited Lean Burn Four-Stroke Large Bore Gas Engine
Ignition process in large bore lean burn gas engines Spark ignites richer mixture in pre-chamber Energetic jets emerges from pre-chamber and ignites main-chamber gas 34 cm bore Tolvan Tolvansson, 2007 Johannes Lindén, Division of Combustion Rikard Wellander, Lund University, Paper 2014-01-1330 1
Ignition process in large bore lean burn gas engines Engine type: 4-stroke Cylinder bore: 340 mm Cylinder stroke: 430 mm Displacement: 39.0 dm3 / cylinder Comp. ratio: 11.6:1 Nbr of valves: 4 Engine speed: 750 rpm Nominal output: 500 kw/cylinder Nominal BMEP: 22.0 bar
Planar Laser Induced Fluorescence Imaging
Fuel tracer PLIF imaging Signal Toluen Aceton Excitation in the UV at 266 nm Resulting fluorescence according to spectra Cyclohexanone Wavelength
Flame jet appearance (Imaged at -9 CAD BTDC) Pree-chamber seeded Main-chamber seeded (TOI: -14 CAD BTDC) Tolvan Tolvansson, 2007 Johannes Lindén, Division of Combustion Rikard Wellander, Lund University, Paper 2014-01-1330 6
High-speed imaging in the Scania D12 engine Cyl. Volume 1951 cm 3 Bore 127 mm Stroke 154 mm Comp. Ratio 16:1 Chamber design Pancake Fuel Ethanol Tracer Acetone Lambda 3.85 Excitation 266 nm
High-speed fuel tracer PLIF in HCCI engines Tracer: Acetone (1 CAD = 139 µs) 50 mm 2 ATDC 2.5 ATDC 3 ATDC 3.5 ATDC 4 ATDC 4.5 ATDC 5 ATDC 5.5 ATDC Gradual consumption of fuel Multiple ignition kernels Sharp gradients at the end of combustion
High-speed fuel tracer PLIF in SI engine 7 ATDC 7.75 ATDC 8.5 ATDC 9.25 ATDC 10 ATDC 10.75 ATDC 11.5 ATDC 12,25 ATDC 7 ATDC 7.75 ATDC 8.5 ATDC 9.25 ATDC 10 ATDC 10.75 ATDC 11.5 ATDC 12,25 ATDC 13juni_v2_5
Probing of formaldehyde distributions Formaldehyde Excitation at 355nm Detection: >400nm 1 0,8 Intensity (a.u.) 0,6 0,4 0,2 Tolvan Tolvansson, 2007 0 350 400 450 500 550 lambda (nm)
Formaldehyde distributions recorded at 7 CAD BTDC for different SOI
Simultaneous detection of formaldehyde and OH Formaldehyde Excitation at 355nm Detection: >400nm OH Excitation at 283nm Detection at 308 nm Delay between the two lasers: 500ns (0.004 CAD @ 1200 rpm)
Formaldehyde and OH distributions for SOI 80 CAD BTDC
Comparison - Different fuels iso-oktan + n-heptan n-dekan SOI=80CAD BTDC, 40% EGR Tolvan Tolvansson, 2007 Johannes Lindén, Division of Combustion
CH visualization in a turbulent flame Tolvan Tolvansson, 2007 Kiefer et al, 31 st Comb. Symp Johannes Lindén, Division of Combustion
Multi species visualization CH, OH
Simultaneous dual-species visualization CH, CH 2 O Li Tolvan et al. Comb. Tolvansson, and Flame, 2007 2010 Johannes Lindén, Division of Combustion Courtesy: Z-S. Li et al.
KCFP Södertälje May 8, 2008 Multi-Species Measurements Tolvan Tolvansson, 2007 Johannes Lindén, Division of Combustion
Multi-Species Laminar flame OH CH CH 2 O Toluene
Multi-Species Turbulent Flames 30 m/s 60 m/s 120 m/s OH CH CH CH 2 O CH 2 O Tolu. OH CH CH CH 2 O CH 2 O Tolu. OH CH CH CH 2 O CH 2 O Tolu.
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