ecn 3 diesel combustion topic 2: mixing/chemistry interaction synthesis
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ECN 3 Diesel Combustion Topic 2: Mixing/chemistry interaction SYNTHESIS. José M. García Oliver CMT-UPVLC Ann Arbor, April 4th 2014. ACKNOWLEDGEMENTS. Organizers & contributors Gilles Bruneaux , Raúl Payri , Lyle Pickett Unvisible contributors …. - PowerPoint PPT PresentationTRANSCRIPT
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ECN 3
Diesel Combustion Topic 2: Mixing/chemistry interaction
SYNTHESISJos M. Garca Oliver CMT-UPVLCAnn Arbor, April 4th 2014ACKNOWLEDGEMENTSOrganizers & contributors
Gilles Bruneaux, Ral Payri, Lyle PickettUnvisible contributorsMichele BardiMichelle BollaYuri WrightETH-ZurichHuber Baya-TodaLouis-Marie MalbecIFPENOlawole KutiKAUSTSeong-Young LeeMTUDan HaworthPenn StGianluca D'ErricoPoli. di MilanoLyle PickettScott SkeenSandiaSandiaMaarten MeijerBart SomersTU/eEvatt HawkesUNSWHu WangUWiscECNECN 3 Synthesis of Topic 2
#April 4th 2014ECN1ECN2StandardizationComparison among contributorsStandardization Comparison among contributorsSA standardSA + parametricsShort/Long Injection
LOL, IDLOL,ID2D: PIV, SVF
SPRAY COMBUSTION FROM ECN1 TO ECN3
EXPERIMENTSECNECN 3 Synthesis of Topic 2
#April 4th 2014ECN1ECN2Comparison among modelsComparison among modelsn-heptaneSA + parametricsShort InjectionLOL, IDLOL, IDSVF (n-heptane)SPRAY COMBUSTION FROM ECN1 TO ECN3
SIMULATIONSECNECN 3 Synthesis of Topic 2
#April 4th 2014ACHIEVEMENTSExtension of experimental DB information with Injectors/Techniques/SootLOL ID extensively used
New indicators (sr, FL) bring in new information on TCIMore validation from modelling is needed
Analysis on OH*/OH
Detailed analysis of OH and CH2O fields
Improved analysis of soot under SA conditions
ECNECN 3 Synthesis of Topic 2
#April 4th 2014
Ignition Delay (All Data)
Lift-off length (LOL)ID/LOL - EXPERIMENTSLOL shows a single trend with small differences among institutions + low uncertaintyID shows more scattering, with high uncertainty when measured with pressure signalECNECN 3 Synthesis of Topic 2
#April 4th 20146Clear overestimation of ID, mainly due to limitations of the chemistry descriptionMore evident with well-mixed modelsBetter prediction of LOL
ID/LOL - MODELLINGECNECN 3 Synthesis of Topic 2
#April 4th 20147Fuel injection pressure sweep
Ignition delay and Lift-off have opposite trend as function of the injection pressure
ID/LOL - MODELLINGHow do models explain the effect of injection pressure on ignition delay?ECNECN 3 Synthesis of Topic 2
#April 4th 20148ACHIEVEMENTSExtension of experimental DB information with Injectors/Techniques/SootLOL ID extensively used
New indicators (sr, FL) bring in new information on TCIMore validation from modelling is needed
Analysis on OH*/OH
Detailed analysis of OH and CH2O fields
Improved analysis of soot under SA conditions
ECNECN 3 Synthesis of Topic 2
#April 4th 2014
REACTIVE SPRAY TIP PENETRATIONGlobal combustion indicatorGood repeatability among institutions/injectors in the experimentsMore scattering when comparing modelling approaches
EXPERIMENTSMODELLINGECNECN 3 Synthesis of Topic 2
#April 4th 201410REACTIVE SPRAY TIP PENETRATIONReacting vs non-reactingComparison with inert case is key issue for understanding Sr (see Bridge the gap on April 5th)Sr/Si should be further analyzed
EXPERIMENTSMODELLING
ECNECN 3 Synthesis of Topic 2
#April 4th 201411Experimental definition + Scaling lawStabilized Flame Length is a combustion indicator that contains both mixing and combustion-related info
CMT 675 - Spray A - 15% O2STABILIZED FLAME LENGTHmixing Combustion-relatedCFD VALIDATION?ECNECN 3 Synthesis of Topic 2
#April 4th 201412ACHIEVEMENTSExtension of experimental DB information with Injectors/Techniques/SootLOL ID extensively used
New indicators (sr, FL) bring in new information on TCIMore validation from modelling is needed
Analysis on OH*/OH
Detailed analysis of OH and CH2O fields
Improved analysis of soot under SA conditions
ECNECN 3 Synthesis of Topic 2
#April 4th 2014
Experimental LOLFair agreement in LOL between both results although with inconsistencies
Can this be standardized?OH LIF vs OH* chemECNECN 3 Synthesis of Topic 2
#April 4th 201414Is it possible to use a LOL definition based on OH*?
POLIMI - AROH OH*
Trend seems to captured despite the very low values.A different threshold would be needed to be consistent with the OH based definition.
OH vs OH*How reliable are OH* predictions by the simulationECNECN 3 Synthesis of Topic 2
#April 4th 201415ACHIEVEMENTSExtension of experimental DB information with Injectors/Techniques/SootLOL ID extensively used
New indicators (sr, FL) bring in new information on TCIMore validation from modelling is needed
Analysis on OH*/OH
Detailed analysis of OH and CH2O fields
Improved analysis of soot under SA conditions
ECNECN 3 Synthesis of Topic 2
#April 4th 2014FLAME STRUCTUREEXPERIMENTS + MODELINGDetailed analysis of flame evolution: OH, CH2OInteresting similarities in spite of the differences in starting conditions
Stage I (around 0.6 ms) : CH2O @ 0.4ms
ECNECN 3 Synthesis of Topic 2
#April 4th 2014
FLAME STRUCTUREEXPERIMENTS + MODELINGDetailed analysis of flame evolution: OH, CH2OInteresting similarities in spite of the differences in starting conditionsStage I (around 0.6 ms) : OH @ 0.55ms
ECNECN 3 Synthesis of Topic 2
#April 4th 2014FLAME STRUCTUREEXPERIMENTS + MODELINGDeeper understanding of flow structure evolution along different stages by comparing both predictions and experiments relatingReactive penetrationVelocity/density fields
To which extent are differences in local flow due to the spray or the TCI models?ECNECN 3 Synthesis of Topic 2
#April 4th 2014ACHIEVEMENTSExtension of experimental DB information with Injectors/Techniques/SootLOL ID extensively used
New indicators (sr, FL) bring in new information on TCIMore validation from modelling is needed
Analysis on OH*/OH
Detailed analysis of OH and CH2O fields
Improved analysis of soot under SA conditions
ECNECN 3 Synthesis of Topic 2
#April 4th 2014
1.5 ms2 ms2.5 msExperiment: KL signalSimulation: SVFSOOTQualitative agrement, further work is neededWhich differences are due to combustion model?ECNECN 3 Synthesis of Topic 2
#April 4th 2014
TOTAL SOOT MASSOnset of soot formation
SOOTOnset of soot delayed with IDInitial peak due to transient head, why is it not predicted?ECNECN 3 Synthesis of Topic 2
#April 4th 2014RECOMMENDATIONS FOR ECN3SIMULATIONSA more accurate chemistry model is needed Subtopic for ECN4?Why not testing spray A with a fuel with a better known chemistry, e.g. n-heptane?
Well-mixed model issue less accurate predictions of ID/LOL than TCI ones
BUT more validation is needed to fully discern prediction capabilities regardingVelocity field (PIV), FL, PenetrationECNECN 3 Synthesis of Topic 2
#April 4th 2014RECOMMENDATIONS FOR ECN3SIMULATIONSInert vs reacting spray Always simulate an inert case as a baseline upon which the reacting case can be comparedThis can rule out differences due to spray mixing
Soot models need to be investigated with a closer look at the combustion model
LES contributions are welcome
ECNECN 3 Synthesis of Topic 2
#April 4th 2014RECOMMENDATIONS FOR ECN3EXPERIMENTSAny technique that delivers information on local temperature/composition under reacting condition is welcome!More 2D Information is essential
More extensive radiation measurementsCloser look into soot-radiation link
ANALYSIS FROM EXPERIMENTS+MODELLINGAre we able to describe the spray flow time evolution?
ECNECN 3 Synthesis of Topic 2
#April 4th 2014RECOMMENDATIONS FOR ECN3ADDITIONAL IDEASAfter EOI flame dynamics
DB extension with multiple injections/larger orifice size
ECNECN 3 Synthesis of Topic 2
#April 4th 2014