INTRODUCTION JM GarcíaOliver UPVLC March 31 st 2017 1 DIESEL COMBUSTION EXPERIMENTS Combustion Recommendations Use high sensitivity imaging to detect highT luminosity Let soot that forms later saturate your imaging system ID: 1043999
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1. ECN5 – Diesel Combustion INTRODUCTIONJM García-Oliver (UPVLC)March 31st, 20171
2. DIESEL COMBUSTION EXPERIMENTS
3. CombustionRecommendationsUse high sensitivity imaging to detect high-T luminosityLet soot that forms later saturate your imaging system.Operate with high time resolution (high framing rate).Use two pressure transducers to resolve spray heat release.Time correction for speed of sound is necessary.Time average lift-off length during the steady portion of combustion, and provide this profile (maximum at any radial location) to eliminate ambiguity about the “knee” or “leveling-off” value.To report a single lift-off length, base it upon 50% of the maximum intensity at the leveling-off value.At higher wavelengths, levels may not decline downstream.More work is needed to understand leveling-off detection at multiple wavelengths.Use this same 50% intensity to determine ignition.
4. DIESEL COMBUSTION EXPERIMENTS
5. OH* time averageSNLCMTIFP and TU/e synchronization with injection is different from CMT and SNL.Noise given by TU/e intensifier is not a problem from the measurementSNLCMTTU/eIFPEN(23.5 kg/m3)IFPEN 2(24kg/m3)Average [mm]17.217.716.416.116.9Std Dev. [mm]0.60.41.20.80.7SNLCMTTU/eIFPENStart [ms]221.50.8End [ms]552.01.3IFPENTU/eSNL #677
6. Ignition DelaySNLCMTTU/eTU/eIFPEN1(23.5kg/m3)IFPEN2(24kg/m3)Average [us]400441400410380405Std Dev. [us]102220Filtered at 310 nmFirst signal detectionNot filtered/ICCD
7. DIESEL COMBUSTION EXPERIMENTS
8. Analysis of flame phases – Spray AsR sinert FTPSOCIIIIIIEOILOL OH*FLSources of information Shadowgraphy (CMT)OH* Chemiluminescence LOL OH* (CMT) Broadband chemiluminescenceFTP(t) = Flame Tip Penetration (CMT)LOL(t) (Sandia)LOL(t)
9. Flame structure – Spray ALiquid phaseFormaldehyde Hot burnt gasesPAHReaction zoneThe formaldehyde structure decreases when increasing tempereature/ [O2]The PLIF-OH signal start « almost » at LOL (OH*)
10. PLIF-OH: 2D comparisons t = 0.7 ms ASOINot the same structure ?Laser profile correction ?Timing ?AI delay differences ?Not the same penetrationAmbient conditions ?Injector to injector variations ?Hydraulic delay ?
11. DIESEL COMBUSTION EXPERIMENTS
12. DESCRIPTION OF REACTING FLOWIncreased spray tip penetrationFlow accelerationRadial dilationNOMINAL Spray AEvidences of:
13. Engine vs Vessel: ID and Lift-off LengthB211200B211200B211200Ignition delayLift-off lengthCombustion indicators are similar between spray B in vessels and engines
14. DIESEL COMBUSTION EXPERIMENTSECN5Enlarged SC/SD experiment databaseDetailed SA ignition experiments
15. DIESEL COMBUSTION MODELLING
16. Good agreement for qualitative trends with some outliers.Over-prediction for most models in Spray A, and models straddle spray H.Absolute agreement generally worse at lower T with over-predicted ignition delay.Spray H results better than spray A. Lower O2 in spray A? Or worse chemistry model?Ignition delay versus Ta
17. DIESEL COMBUSTION MODELLING
18. OH
19. MOTIVATIONFlow analysis @ECN2Large scattering in modelling resultsBoundary conditions?No analysis of velocity/reactive penetration data
20. DIESEL COMBUSTION MODELLING
21. REACTING SPRAY AETHGood description of the flow under reacting conditionsVery high expansion in the Inert-to-reacting transitionEXP-REACTEXP-INERTtime = 1500 us
22. REACTING SPRAY ACMT/Polimi Good overall agreementEXP-REACTEXP-INERTtime = 1500 us
23. Flame structureEarly stages clear differences (AR)ECN4 Kyoto 2015/Flame Structure23OHCH2OOH*
24. DIESEL COMBUSTION MODELLINGECN5Improved mechanismSA Detailed analysis from SOC till EOI
25. DIESEL COMBUSTION AGENDASummary of ECN 5 plansExperimentsEnlarged SC/SD experiment databaseDetailed SA ignition experimentsModellingImproved mechanismSA Detailed analysis from SOC till EOI
26. DIESEL COMBUSTION AGENDA13:00-13:10 DIESEL COMBUSTION TOPICS INTRODUCTION,Jose Garcia-Oliver (CMT)13:10-13:40 SPRAY C & D EXPERIMENTAL SUMMARYJose Garcia-Oliver (CMT)13:40-14:20 IGNITION CHEMISTRYEvatt Hawkes (UNSW)14:20 15:00 IGNITION PROGRESSION TO LIFT-OFF STABILIZATION AND COMBUSTION RECESSIONBart Somers (TU/e)15:30-16:30 SOOTNoud Maes (TU/e), Scott Skeen (Sandia)16:30-16:50 SPRAY B: TEST RIGS VERSUS ENGINESLouis-Marie Malbec (IFPEN)17:00-17:30 FUTURE DIRECTIONS FOR DIESEL COMBUSTION TOPICS