ECN 3: Flame structure 1/19 April 2014 Experimental analysis between LIF- OH/355 from IFPEN, SANDIA and TU/e H. Baya Toda, M. Meijer, N. Maes, S. Skeen, L. Pickett, LM, Malbec, G. Bruneaux Third Workshop of the Engine Combustion Network, April 4-5, 2014, Ann Arbor, USA,

ECN 3: Flame structure 2/19 April 2014 Analyze the spray flame structure Assess the repeatability of measurements among different institutions Improve measurements/post-processing for more reliable results for next ECN meetings Objectives

ECN 3: Flame structure 3/19 April 2014 Flame phases – spray A Operating conditions for comparisons Hardware comparisons 2D and 1D profiles comparisons Contents

ECN 3: Flame structure 4/19 April 2014 Analysis of flame phases – Spray A sRsR s inert FTP SOC IIIIII EOI LOL OH* FL Sources of information – Shadowgraphy (CMT) – OH* Chemiluminescence  LOL OH* (CMT) – Broadband chemiluminescence FTP(t) = Flame Tip Penetration (CMT) LOL(t) (Sandia) LOL(t)

ECN 3: Flame structure 5/19 April 2014 Analysis of flame phases – Spray A sRsR s inert FTP SOC IIIIII EOI LOL OH* FL LOL(t) Combustion stages – (I) = Autoignition and early development From SOC until reacting penetration accelerates over inert case The reacting spray undergoes a transition from inert to reacting flow

ECN 3: Flame structure 6/19 April 2014 Analysis of flame phases – Spray A sRsR s inert FTP SOC IIIIII EOI LOL OH* FL LOL(t) Combustion stages – (II) = Mature flame From the end of (I) until EOI (IIA) Transient mature flame – LOL still unsteady (upto 2000 us) (IIB) Quasi-steady mature flame – LOL steady but FTP increasing (upto 4000 us) (IIC) Steady flame – FTP steady (FL)

ECN 3: Flame structure 7/19 April 2014 Analysis of flame phases – Spray A sRsR s inert FTP SOC IIIIII EOI LOL OH* FL LOL(t) Combustion stages – (III) = Burn-out phase From EOI onwards

ECN 3: Flame structure 8/19 April 2014 Operating conditions for comparisons PhasesIFPENSANDIATU/e PLIF-355Transient0.7 ms X Stabilized2.7 ms2.5 ms4.7 ms* PLIF-OHTransient0.7 msX0.7 ms* Stabilized4.7 msX4.7 ms* * Assuming an identical hydraulic delay as at IFPEN: 300us sRsR s inert FTP SOC IIIIII EOI LOL OH* FL LOL(t)

ECN 3: Flame structure 9/19 April 2014 Hardware differences IFPENSANDIATU/e Injectors PLIF-355Laser sheet55 mm65 mm90 mm Energy100 mJ 110 mJ PLIF-OHExcitation lineQ 1 (6) Q 1 (9) Energy11-17 mJ11 mJ Laser sheet40 mm*30 mm * Measurements were performed with two laser sheets

ECN 3: Flame structure 10/19 April 2014 Flame structure – Spray A Liquid phase Formaldehyde Hot burnt gases PAH Reaction zone 1.The formaldehyde structure decreases when increasing tempereature/ [O2] 2.The PLIF-OH signal start « almost » at LOL (OH*)

ECN 3: Flame structure 11/19 April 2014 PLIF-355: 2D comparisons Formaldehyde PAH

ECN 3: Flame structure 12/19 April 2014 PLIF-355: 2D comparisons IFPEN SANDIA

ECN 3: Flame structure 13/19 April 2014 PLIF-355: 2D comparisons Formaldehyde

ECN 3: Flame structure 14/19 April 2014 PLIF-OH: 2D comparisons t = 4.7 ms ASOI

ECN 3: Flame structure 15/19 April 2014 Profiles comparison: PLIF-OH

ECN 3: Flame structure 16/19 April 2014 PLIF-OH: 2D comparisons t = 0.7 ms ASOI Not the same structure ? Laser profile correction ? Timing ? AI delay differences ? Not the same penetration Ambient conditions ? Injector to injector variations ? Hydraulic delay ?

ECN 3: Flame structure 17/19 April 2014 PLIF-OH: 2D comparisons t = 0.7 ms ASOI 0.4 ms 0.7 ms 4.7 ms ms

ECN 3: Flame structure 18/19 April 2014 Conclusions Good agreement for PLIF-355 measurments Transient (IFPEN and SANDIA) Steady phase (IFPEN,TU/e and SANDIA) Good agreement for PLIF-OH measurements at steady state phase PLIF-OH comparisons during transient phases are more difficult and need more time for investigation PLIF-OH from TU/e more suitable for LOL estimation because of the stable energy laser

ECN 3: Flame structure 19/19 April 2014 Thank you to all the contributors and good luck to the CFD GUYS !