Slide 1

ECN Topic 1.1 Modeling ResultsCompiled by David P. SchmidtUMass Amherst

*Hanabusa Itch (16521724)#ECNOrganizationTechniquesSpray A Early InjectionSpray A Main InjectionSpray B#ECNInternal Modeling CodesInstitutionANLUMassCMTIFPENSandiaCodeConvergeHRMFoam

Eulerian Spray AtomizationIFP-C3DCLSVOFOriginConvergent ScienceIn-house

In-houseIn-houseIn-houseExternal CouplingNo for A, Yes for BYesYesYesYes* Also included a few results from M. Bode, Aachen RWTH for a simplified geometry and lower Reynolds number#ECNApproachesInstitution/CodeANLConverge

UMassHRMFoam

CMTESAIFPC3D

SandiaLiquid fueln-dodecanen-dodecanen-dodecanen-dodecanen-dodecaneEquation of StateIncomp.Const. compressibility (input error!), perfect gasNon-linear function of p,T, perfect gasStiffened gas EOS, ideal gasNon-linear function of p,T, perfect gasCavitation Enabled?YesNo for A, Yes for BNoYesNoCavitation ModelHomogenous RelaxationHomogenous Relaxation--GERM-Inclusion of turbulent viscous energy generation?NNYYNTurbulenceRANSk-epsilonLESone-eq. eddyRANSSST k-LESSmagorinksyNoneSpatial Discretization2nd order2nd / 1st order1st order2nd orderCell-integrated semi-Lagrangian#ECNComputational DomainInstitution/CodeANLConverge

UMassHRMFoam

CMTESAIFPC3D

SandiaCLSVOFDimensionality33233Cell TypeHex cut cellHex, polyhedralQuad, polyhedralHexEmbedded boundaryCell count (total interior and exterior)2.5M early, 0.8M main2.8M

64K1M74MNeedle motion?YesNoNoYes (lift, no wobble)YesGeometryCNRS yearly, Same as last year for mainSame as last yearLast year(2D)CNRS scanBased on description#ECNBoundary ConditionsInstitution/CodeANLConverge

UMassHRMFoam

CMTESAIFPC3D

SandiaCLSVOFTime Accurate ROI Profile?YesYesYesYesYesInletTime varying total pressureTime varying velocityTime varying static pressureTime varying static pressureFixed static pressureWall BCsL.O.W.SlipNo-slipSlipNo-slipNeedle motion?YesNoNoYes (lift, no wobble)Yes#ECNSpray A Early InjectionSubmissions bySandia, Marco ArientiANL, Michele Battistoni, Qingluan Xue, Sibendu SomIFP, Chawki Habchi, Rajesh Kumar#ECNEarly InjectionA subset of the contributors submitted results that focused on the details of:early needle liftair ingestionthe start of fuel flowtrapped air#ECN

Needle-Filling Movies by IFPNoted how fuel follows the needle surface into the sac#ECNSimulation starts at 200 s (4 m lift)Ends at 400 s210675LIFT

CNRS stl file for sac and nozzleANL Results#ECNNotes:Based on End-of-Injection studies, the sac is likely to be filled with ambient gas, resulting from a previous injection event.Spray A penetration starts at ~310 s after commandNeedle rises slowly until ~310 s after command; afterwards steep rise11ANL Results#ECN

ANL Results#ECN

ANL Results:Mostly dissolved gas, very little vapor#ECNANL Results:

#ECNt = 2.6 ms

t = 76.5 ms t = 173.3 ms

t = 187.6 ms

t = 235.5 ms

t = 315.5 ms t = 325.0 ms

t = 330.0 ms

t = 320.0 ms Axial velocity early opening transient

40 m/s-40 m/s0m/st = 317.5 ms t = 158.8 ms

Axial velocitySandia Results#ECN

520 m/s0m/st = 390.0 ms

t = 336.2 ms

t = 334.8 ms

t = 337.2 ms t = 332.7 ms t = 338.6 ms under-expanded jetAxial velocity opening transient trapped gas

t = 390.7 ms Axial velocitySandia Results#ECNtime [ms]

mass flow AIR [g/s]mass flow FUEL [g/s]0.002557532.40E-0600.1587736-1.23E-0300.1732709-3.82E-0300.1876011.08E-0300.198372.05E-0300.2355461.42E-0300.280205-2.83E-0300.3155186879.29E-0700.317500687-6.54E-0600.319629-8.46E-0400.3249891.12E-0300.3296547.11E-0300.33265562.71E-0200.3347924.90E-0200.33614971.41E-0100.337172.00E-0100.338061.69E-0100.3390211.34E-011.37E-010.33974943.73E-031.442248Mass flows opening transient time [ms]The flows are calculated by integration of the axial flux over a cross-section of the orifice located just before the exitSandia Results#ECN17Trapped gas at t = 390.7 ms

Estimated gas volume ~ 3 10-7 cm3 = 0.0015 VsacThe average density of the gas inside the bubble is ~ 0.2 g/cm3The estimated residual gas mass is therefore 6 10-8 g

ZY

Sandia Results#ECNObservationsComputationally, we can predict air ingestion and delay due to sac filling

Unresolved: Is fuel filling the sac as a quasi one-dimensional process or does the fuel follow the needle?

Prediction of under-expanded jet

Unresolved: Prediction of trapped air#ECNSpray A Main InjectionSubmissions byANL, Qingluan Xue, Michele Battistoni, Sibendu SomUMass, Maryam Moulai, David SchmidtCMT, Pedro Marti Gomez-Aldaravi, Raul PayriIFP, Chawki Habchi#ECNMass Flow Rate

#ECNCoefficient of Discharge

#ECNWhat are the latest experimental values of discharge coefficients?22Coefficient of Velocity

#ECNCoefficient of Area

#ECNSpray A SnapshotsAll taken at t = 0.75 ms#ECN

Velocity, Transverse (x-y) ViewANLUMass

CMT

IFPEN

#ECN

Velocity at the Exit

ANL

IFPENCMTUMass

Aachen

#ECN

Density, Transverse (x-y) ViewUMassCMT

ANL

IFPEN

* Due to input error, the UMass density was too low.#ECNIdea from Pedro MartiPerhaps viscous dissipation in the turbulent boundary layer raises the temperature and decreases the density of the liquid near the wall#ECN

Density at the Exit

ANLUMassIFPENCMTDensity at nominal exit t,p : 741 kg/m3* Due to input error, the UMass density was too low.#ECNTemperature, Transverse (x-y) View

ANLUMassIFPEN

CMT

#ECN

Temperature at the Exit

UMassIFPEN

ANLCMT

#ECNTurbulence, Transverse (x-y) View

ANLUMassIFPENCMT

#ECN

Turbulence at the Exit

ANLUMassIFPEN

Aachen

CMT#ECNSpray BESRF geometry is incomplete, but more accurateInitial simulation with the Phoenix tomography

ESRFPhoenix#ECNContributionsInstitutionsUMassANLPeopleMaryam Moulai, David Schmidt Michele Battistoni, Qingluan Xue, Sibendu Som

ApproachEulerian cavitation, spray developmentAdaptive mesh Eulerian-EulerianCodeIn-houseConvergeNeedle motionnoneyesGeometryReduces ESRFPhoenix#ECN

ANL Contribution

#ECN

Hole 3Hole 2Hole 1Spray B: Hole slices of liquid volume fraction and velocity

ANL Contribution#ECNA closer examination of hole 3ANL Contributiont = 100 ms ASOI

#ECNSpray BRough geometry from Phoenix STL is smoothed, slightlyRoughness causes large spatial pressure fluctuations in nozzle, especially near exitHole 3 produces a wider spray than the other holes

UMass contributionHole 1Hole 2Hole 3#ECN

Connecting internal flow to external spray

Hole 1Hole 2Hole 3UMass contribution

Mass fraction of gas#ECNCavitation?

Volume fraction of fuel vaporAs the holes diverge near the exit, trace amounts of vapor appearNo cavitation predicted at nozzle inletsUMass contributionHole 1Hole 2Hole 3#ECNMain Injection ConclusionsSome differences between results with new and old 675 geometriesWith no slip walls, temperature variation due to viscous energy generationStiffened gas EOS is overly compressible, UMass results included incorrect density inputMostly, matched experimental Cv,Ca, CdRoughness effects in Phoneix spray B geometryMatched mass flow trends with CSI spray B geometryWide spray from hole 3, with perhaps, a little cavitation, just at the exit

#ECN