study the effects of charge motion control on fuel published … · 2018-06-12 · abstract an...

ABSTRACTAn experimental study is performed to investigate the effectsof charge motion control on in-cylinder fuel-air mixturepreparation and combustion inside a direct-injection spark-ignition engine with optical access to the cylinder. High-pressure production injector is used with fuel pressures of 5and 10 MPa. Three different geometries of charge motioncontrol (CMC) device are considered; two are expected toenhance the swirl motion inside the engine cylinder whereasthe third one is expected to enhance the tumble motion.Experiments are performed at 1500 rpm engine speed withthe variation in fuel injection timing, fuel pressure and thenumber of injections. It is found that swirl-type CMC devicessignificantly enhance the fuel-air mixing inside the enginecylinder with slower spray tip penetration than that of thebaseline case without CMC device. Combustion images showthat the flame growth is faster with CMC device compared tothe similar case without CMC device.

INTRODUCTIONImprovement in fuel efficiency and reduction in exhaustemissions are the main goals behind the new developments ininternal combustion engines (Mittal et al., 2010). The conceptof direct-injection spark-ignition (DISI) engine has thepotential to achieve such goals. In this technology, fuel isdirectly injected into the engine cylinder, which offers greatflexibility to control the fuel injection timing, its duration andthe number of injections. Note that the fuel-air mixture

preparation in the combustion chamber is one of the keyfactors that influence the in-cylinder combustioncharacteristics and hence the engine performance (Hung etal., 2007). Therefore, optimizing the fuel-air mixturehomogeneity is an important parameter for the enginedesigners. In general, a homogeneous fuel-air mixture isachieved by injecting the fuel during the intake stroke. Inaddition, the use of a charge motion control (CMC) device isan important factor that affects the flow (Mittal and Schock,2010) and hence the fuel-air mixing and combustion insidethe engine cylinder. It is expected that the CMC deviceimparts an angular momentum to the charge entering theengine cylinder.

Several studies have been reported to investigate theinfluence of charge motion control on the engineperformance. Clarke and Stein (1999) combined the variablevalve timing with the charge motion control valve (CMCV).Variable valve timing was obtained using the dual equalvariable camshaft timing (VCT) strategy. The combination ofdual equal VCT with a CMCV allows an engine to beoperated either at or near stoichiometric or at lean conditions,which allows the use of a NOx trap for the purpose of furtherreducing air pollutants. The authors indicated that the synergybetween the CMCV and the dual equal VCT allows the fuelconsumption to be less than the fuel consumption during leanoperation at standard valve timing. This is due to the fact thatCMCV increases the in-cylinder charge motion, and henceimproves the combustion and the ability to handle the chargedilution, which occurs from increased levels of internal

High-Speed Flow and Combustion Visualization toStudy the Effects of Charge Motion Control on FuelSpray Development and Combustion Inside a Direct-Injection Spark-Ignition Engine

2011-01-1213Published

04/12/2011

Mayank MittalMSU College of Engineering

David L.S. Hung, Guoming Zhu and Harold SchockMichigan State Univ.

Copyright © 2011 SAE International

doi:10.4271/2011-01-1213

SAE Int. J. Engines | Volume 4 | Issue 1 1469

Downloaded from SAE International by Brought To You Michigan State Univ, Tuesday, June 12, 2018

http://dx.doi.org/10.4271/2011-01-1213

exhaust gas recirculation resulting from valve timing retard.Li et al. (2000) investigated the effects of swirl control valveon in-cylinder flow using a laser doppler anemometrytechnique. Mittal and Schock (2010) used molecular taggingvelocimetry to study the influence of charge motion controlon in-cylinder flow inside an internal combustion engineassembly. Kim et al. (2005) investigated the effects ofinjection timing and intake port flow control on fuel wettinginside the engine cylinder. They found that a tumble mixture-motion plate inside the intake port significantly reducedcylinder liner and piston top fuel wetting. This is because theuse of the tumble mixture-motion plate provided moreturbulence, which effectively enhanced the mixing during theintake process. Lee and Heywood (2006) studied the effectsof CMCV on combustion characteristics and hydrocarbonemissions. The authors concluded that CMCV improvedmixture preparation due to increased swirl and tumbleintensities which enhanced fuel transport, distribution, andevaporation. CMCV in the closed condition allowed reducedfuel injection and retarded spark timing strategies thatreduced hydrocarbon emissions significantly during the coldstart due to greater fuel evaporation and faster burning rate.

Overall, previous investigations show that a charge motioncontrol device is an important factor that controls thecombustion process, and hence, influences the engineperformance (Mittal and Schock, 2010). However, to the bestof authors' knowledge, visualization studies of the chargemotion control device on in-cylinder fuel-air mixturepreparation and combustion are not available. Therefore, anexperimental study is performed to investigate the effects ofcharge motion control on in-cylinder fuel-air mixturepreparation and combustion inside a direct-injection spark-ignition engine. Experiments were performed at 1500 rpmengine speed with the variation in fuel injection timing, fuelpressure and the number of injections. In the followingsections, a detail of experimental setup is first outlined,followed by the results of various tests performed. Finally,concluding remarks are summarized from this work.

EXPERIMENTAL SETUPThe engine used in the present work is a four-valve, twointake and two exhaust, 0.4 liter single-cylinder spark-ignition engine. It has a bore diameter of 83 mm and strokelength of 73.9 mm. A flat-top piston with optical access isused. This provided a compression ratio of 9.75:1. Mittal etal. (2010) used a custom-designed piston in the same engine,which allowed the compression ratio of 13.5:1. The headaccommodates a pressure transducer to record the in-cylinderpressure data. A view of the combustion chamber geometryshowing intake and exhaust valves, direct-injector, spark plugand the pressure transducer is illustrated in Figure 1 (Mittal etal., 2010). It should be noted that in this paper 0° crank anglecorresponds to the top dead center (TDC) of the compression,and therefore, −180 crank angle degrees (CAD) corresponds

to the bottom dead center (BDC) of the intake, i.e. 180°BTDC (before top dead center). Different fuel injectiontimings (240°, 210° and 180° BTDC) are considered withgasoline fuel. A high-pressure direct-injection (HPDI) 7-holeinjector (Mittal et al., 2010) is used with the fuel pressures of5 and 10 MPa.

Figure 1. Optical engine combustion chamber

SETUP FOR FUEL SPRAYVISUALIZATIONFigure 2 shows the experimental rig used for sprayvisualization tests. The laser is introduced into the cylinderthrough the flat-top piston with optical access. A Miescattering technique is used to visualize the liquid phase ofthe fuel dispersion inside the combustion chamber. A quartzcylinder is used to provide the optical access to the cylinderfor high-speed imaging. The fuel spray was imaged with aPhotron APX-RS non-intensified highspeed CMOS camerawith a Nikon 105 mm AF micro lens. The camera was set tooperate at 10 kHz, which provided an image size of 512 ×512 pixels. At 1500 rpm engine speed, each framecorresponds to 0.9 crank angle degrees. A high repetition ratepulsed copper vapor laser, synchronized with the high-speedcamera and the fuel injection timing logic, was used toilluminate the liquid fuel dispersion. For each test condition,the engine was first motored to reach the desired rpm, i.e.1500 rpm. Once the engine was stabilized, a signal from theCosworth engine controller was sent out to the fuel injector totrigger the start of injection at a specific crank angle positionas well as to trigger the camera to start recording thespecified number of images in consecutive cycles. The fuelinjection duration at each test point is defined to achieve astoichiometric air-fuel ratio based on gasoline. For eachimaging test, five-injection-cycle spray images were recordedto visualize the fuel dispersion with 400 consecutive framesfrom each cycle.

SAE Int. J. Engines | Volume 4 | Issue 11470


SETUP FOR COMBUSTIONVISUALIZATIONFigure 3 shows the experimental rig for combustionvisualization. Note that the quartz cylinder was replaced withthe metal cylinder for the combustion tests. Experiments wereperformed at 1500 rpm engine speed with part-load condition(0.45 bar MAP). This part-load condition was selected due tooptical limitations of the flattop piston. The effects of split (ordual) injection were also studied and compared with thecorresponding cases of single injection by maintaining thesame relative air-to-fuel ratio (λ), inverse of fuel-to-airequivalence ratio (φ). With the split injection, the secondinjection was 90 CAD apart from the first injection and thetwo pulse widths (of fuel injection) were kept the same. Thecombustion images were captured by Photron APX-RShighspeed camera (operated at 10 kHz) through the opticalpiston. For each test condition, the engine was first motoredto reach the desired rpm. Once the engine was stabilized, asignal from the Opal-RT engine controller was sent out to thefuel injector to trigger the start of injection at a specific crankangle position as well as to trigger the camera at the sparktiming crank angle position to start recording the specifiednumber of images in consecutive cycles. The fuel injectionduration at each test point was selected to achieve the desiredrelative air-to-fuel ratio. For each imaging test, fortyconsecutive cycles were recorded to visualize the combustionprocess with 200 frames from each cycle. Due to opticalengine limitations, the fuel supply was cut off as soon as the

camera recorded the specified number of cycles. In-cylinderpressure was recorded with one degree of crank angleresolution that has been synchronized with the imagingsignal. The Kistler piezoelectric pressure transducer was usedwith the measurement range varying from 0 to 250 bars. Theaveraged in-cylinder pressure data is then used to evaluate theengine performance. Mass fraction burned (MFB) and burndurations are determined using the well-known Rassweiler-Withrow method (Rassweiler and Withrow, 1938). A linearmodel for the polytropic index during the combustion processis used to evaluate the pressure change due to the volumechange (Mittal et al., 2009).

Figure 2. Experimental rig for in-cylinder fuel spray visualization

Figure 3. Experimental rig for combustion visualization



CHARGE MOTION CONTROL DEVICEThe charge motion control device was installed between theintake manifold and the intake port. The nature of CMCdevice influence depends on its geometry. Three differentgeometries of charge motion control device were considered(see Figure 4); two are expected to enhance the swirl motioninside the engine cylinder whereas the third one is expectedto enhance the tumble motion. Each CMC device used in thisstudy reduced the port cross sectional area by about 75%, i.e.,the flow area about 25%. Experiments were performed withboth the conditions: CMC device open (i.e. without CMCdevice) and CMC device closed (i.e. with CMC device).

RESULTS AND DISCUSSIONResults of fuel spray development; combustion visualizationand in-cylinder pressure analyses are presented for a direct-injection spark-ignition engine with both open (without) andclosed (with) charge motion control devices. Three differentgeometric configurations of charge motion control device areconsidered.

FUEL SPRAY VISUALIZATIONFigure 5 shows the spray development of gasoline with open(left column) and closed CMC devices of all threeconfigurations, i.e. swirl-types 1 (second column) and 2 (thirdcolumn) and tumble-type (right column). In each case, high-pressure direct-injection injector is used with 5 MPa ofinjection pressure at 1500 rpm engine speed. The start ofinjection (SOI) is at −240 crank angle degrees (or 240°BTDC). The size of each spray image shown in this paper is512 × 512 pixels. The physical size of a pixel is about 0.19mm. Note that the intake valves are located towards the leftside of each spray image. The spray development at 223.8°BTDC shows that the spray tip penetration is faster withtumble-type CMC device compared to the baseline case withopen CMC device. However, it is to be noticed that the spraytip penetration is slower with swirl-type CMC devicescompared to both open and tumble-type CMC devices. Sprayimages at 216.6° BTDC clearly show that the spray tippenetration is even slower with swirl type-1 CMC devicecompared to the swirl type-2 CMC device. It is interesting tonote that no significant difference is observed in spray

development when the baseline case (with open CMC device)is compared with the tumble-type CMC device. However, thefuel dispersion is wider with swirl-type CMC devices. Also,note that the intensity values in these images (with swirl-types 1 and 2) are relatively low compared to the intensityvalues in spray images of both open and tumble-type CMCdevices (see the presence of more liquid fuel towards the leftside of the piston top with both open and tumble-type CMCdevices). This clearly shows that the air-fuel mixing improveswith swirl-type CMC devices with reduced piston topimpingement.

Figure 6 shows the spray development of gasoline with openand closed CMC devices of all three configurations. In eachcase, an HPDI injector is used with 5 MPa of injectionpressure at 1500 rpm engine speed. The start of injection is at180° BTDC. Similar to the results observed with SOI at 240°BTDC, the spray tip penetration is slower with swirl-typeCMC devices than that of open and tumble-type CMCdevices. Note that the fuel dispersion is wider with swirl- andtumble-type CMC devices than that of open CMC device.Therefore, it is expected that the air-fuel mixing improveswith the charge motion control device.

SPRAY TIP PENETRATIONFigure 7 shows the effects of injection pressure (at 5 and 10MPa) and the injection timing (at 240° and 180° BTDC with5 MPa of injection pressure) on spray tip penetration withopen CMC device. The penetration length is determined asthe axial location of the spray tip from the injector tip. Asexpected, the spray tip penetration is faster with the injectionpressure of 10 MPa than that of 5 MPa. Note that the spraytip penetration is slower when fuel injection starts at 180°BTDC than that of 240° BTDC injection timing due toupward movement of the piston. Figure 8 shows the effects ofdifferent configurations of charge motion control devices onspray tip penetration. As observed in spray images (of Figure5), the spray tip penetration is faster with tumble-type CMCdevice compared to open and swirl-type CMC devices. Notethat the spray tip penetration is slowest with swirl type-1CMC device compared to open and other configurations(swirl type-2 and tumble-type) of CMC devices.

Figure 4. Three different types of charge motion control devices: (a) Swirl type-1, (b) Swirl type-2 and (c) Tumble type CMCdevices



Figure 5. Spray development with (a) Open, (b) swirl-type 1, (c) swirl-type 2 and (d) tumble-type CMC devices at 5 MPa ofinjection pressure with SOI at 240° BTDC



Figure 6. Spray development with (a) Open, (b) swirl-type 1, (c) swirl-type 2 and (d) tumble-type CMC devices at 5 MPa ofinjection pressure with SOI at 180° BTDC



COMBUSTION VISUALIZATION ANDIN-CYLINDER PRESSURE ANALYSESCombustion visualization and in-cylinder pressure analysesare presented with open and closed (swirl type-2) CMCdevices. The characteristics displayed in the combustionimages, such as the flame sizes, shapes and appearance, mayprovide useful insight into what happens over the combustionperiod (Aleiferis et al., 2008). It should be pointed out herethat the images presented are a two-dimensionalrepresentation of the three-dimensional flame developmentinside the engine cylinder. Also, it is to be noticed that eachcombustion image shown in this paper is a reduced form ofits original image size of 512 × 512 pixels to 420 × 420 pixels(for better visibility to the reader) by eliminating the darkarea band of pixels outside the cylinder. The physical size ofa pixel is about 0.22 mm.

Figure 9 shows the stoichiometric combustion images ofgasoline with single injection for both open and closed (swirltype-2) CMC devices at 25.2°, 28.8°, 31.5° and 34.2° afterspark timing (AST). High-pressure direct-injection injector isused at 5 MPa of injection pressure. The images are enhancedso that the early flame development and its growth is clearlyvisible to the reader for comparison purpose. The sparktiming (ST) was at 35° BTDC based on MBT. The MBTtiming at each test point was determined based on themaximum value of the mean IMEP during the spark sweep.The engine was operated at 1500 rpm with part-loadcondition. In each case the start of injection was considered at210° BTDC. Note that Mittal et al. (2010) showed lessoverall impingement on in-cylinder surfaces in the sameengine at this injection timing, and due to this, injection

Figure 8. Effect of charge motion control device on spray tip penetration

Figure 7. Effect of injection pressure and injectiontiming on spray tip penetration



Figure 9. Flame images of gasoline with single injection (λ =1 and ST = 35° BTDC) using HPDI injector at 5 MPa with open(upper) and closed (lower) CMC devices

Figure 10 shows the combustion images of gasoline with split(or dual) injection for both open and closed CMC devices at25.2°, 28.8°, 31.5° and 34.2° after the spark timing. In eachcase, the start of first injection was at 210° BTDC withinjection pressure of 5 MPa. The start of second injection wasat 120° BTDC (90 CADs apart from the first injection). Notethat the total amount of fuel was divided equally in both theinjections for stoichiometric air-to-fuel condition. The sparktiming was at 32° BTDC based on MBT. The combustionimages show that the flame growth is much faster with closedCMC device than that of open CMC device. It is to benoticed that some bright rich spots are also visible in thecombustion images (more with open CMC device than that ofclosed CMC device) of split injection. This may be occurringdue to droplet burning (Aleiferis et al., 2008). Early start ofthe second injection may help to reduce these hot spots byallowing more mixing time. Also, hot in-cylinder conditionsof the metal engine may help to reduce these hot spots due tofaster evaporation of liquid fuel inside the engine cylinder.Aleiferis et al. (2008) discussed that gasoline is particularlysusceptible to these hot spots.

timing of 210° BTDC is selected. The intake valves in all thecombustion images are located towards the upper half of theimages. It is evident from the images that the flame growth isslower with open CMC device than that of closed CMCdevice. It is expected that there will be some cycle-to-cyclevariations in the flame development.

Figure 11 shows the averaged in-cylinder pressures forgasoline at stoichiometric conditions for both open and closedCMC devices with both single and split injections. An HPDIinjector at 5 MPa is used in each case. It can be observed thatthe peak in-cylinder pressure increases with the split injection

that of its corresponding open CMC device case for singleinjections. Similarly, for open CMC device the peak in-cylinder pressure location is 2 CAD earlier with splitinjection than that of its corresponding case of singleinjection. The mean IMEPs are 2.59 and 2.73 bar with openCMC device for single and split injections, respectively. Thisshows that the mean IMEP increases with the split injectionthan that of its corresponding case with the single injection.The mean IMEPs with closed CMC device are 2.52 and 2.58bar for single and split injections, respectively. This showsthat the mean IMEP reduces with closed CMC device thanthat of its corresponding case with open CMC device. This isexpected due to increased pumping power with the closedCMC device.

than that of the corresponding case with single injection.Also, the peak in-cylinder pressure is slightly higher with theclosed CMC device than that of open CMC device. It isnoticed that the crank angle at which the peak in-cylinderpressure occurs is 2 CAD earlier for closed CMC device than



Figure 11. Averaged in-cylinder pressure for gasoline (λ=1) with open and closed CMC devices for both single

and split injections at 5 MPa of injection pressure

Figure 10. Flame images of gasoline with split injection (λ =1 and ST = 32° BTDC) using HPDI injector at 5 MPa with open(upper) and closed (lower) CMC devices

Figure 12. Mass fraction burned for gasoline (λ =1) withboth open and closed CMC devices for single and split

injections at 5 MPa of injection pressure



Figure 12 shows the mass fraction burned curves calculatedfrom the averaged in-cylinder pressure data shown in Fig. 11.It can be observed that the burning is faster with closed CMCdevice than that with open CMC device. Similarly, it is fasterwith split injection than that of single injection. The 10%burn locations for single injections are at 0 and −1 CAD foropen and closed CMC devices, respectively. With splitinjections, the total burn durations (10% - 90%) are 24 and 27CAD for closed and open CMC devices, respectively.Therefore, the total burn duration decreases with the closedCMC device more than with the open CMC device.

Figure 13 shows the stoichiometric combustion images ofgasoline with single injection for both open and closed CMCdevices at 25.2°, 28.8°, 31.5° and 34.2° after the sparktiming. An high-pressure direct-injection injector is used at10 MPa of injection pressure. The spark timing was at 35°BTDC based on MBT. The engine was operated at 1500 rpmwith part-load condition. In each case the start of injectionwas at 210° BTDC. It is evident from the images that theflame growth is much faster at higher injection pressure of 10MPa than that of lower injection pressure of 5 MPa (seeFigure 9 for comparison). Also, at this higher injectionpressure of 10 MPa, some bright spots are visible with openCMC device compared to the combustion images with closedCMC device.

Figure 13. Flame images of gasoline with single injection (λ =1 and ST = 35° BTDC) using HPDI injector at 10 MPa with open(upper) and closed (lower) CMC device

Figure 14. Averaged in-cylinder pressure for gasoline (λ=1) with open and closed CMC devices (single injections)

at 10 MPa of injection pressure

Figure 14 shows the averaged in-cylinder pressures forgasoline at stoichiometric conditions for both open and closedCMC devices with single injection. An HPDI injector wasused with 10 MPa pressure in each case. No significantdifference is observed in peak in-cylinder pressure values atthis higher injection pressure (of 10 MPa) with open andclosed CMC devices. However, the crank angle at which thepeak in-cylinder pressure occurs is 1 CAD earlier for closedCMC device than that of open CMC device. The peak in-cylinder pressure is about 14.8 bar for both cases. The meanIMEPs are 2.78 and 2.62 bar with open and closed CMCdevices, respectively.



Figure 15. Mass fraction burned for gasoline (λ =1) withopen and closed CMC devices (single injections) at 10

MPa of injection pressure

Figure 15 shows the mass fraction burned curves calculatedfrom the averaged in-cylinder pressure data shown in Figure14. As seen earlier, it can be observed that the burning isfaster with closed CMC device than that of open CMC deviceat this higher injection pressure of 10 MPa. The 10% burnlocations are at −2 and −3 CAD for open and closed CMCdevices, respectively. The total burn durations (10% - 90%)are 23 and 26 CAD for closed and open CMC devices,respectively. Therefore, similar to the results at 5 MPa ofinjection pressure, the total burn duration decreases withclosed CMC device than that of open CMC device.

CONCLUSIONSAn experimental study was performed to investigate theeffects of charge motion control on in-cylinder fuel-airmixture preparation and combustion of a direct-injectionspark-ignition engine. High-pressure production injector wasused with fuel pressures of 5 and 10 MPa. Experiments wereperformed at 1500 rpm engine speed with the variation in fuelinjection timing, fuel pressure and the number of injections. Itis found that swirl-type charge motion control devicessignificantly enhance the fuel-air mixing inside the enginecylinder compared to the baseline case with open CMCdevice. In addition, the spray tip penetration is found to beslower with swirl-type CMC devices compared to the casewith open CMC device. The results of combustionvisualization show that the flame growth increases with theincreased fuel injection pressure. The peak in-cylinderpressure also increases with the increased injection pressure.The effects of CMC device on flame growth are moresignificant at lower fuel injection pressure of 5 MPa than thatof higher injection pressure of 10 MPa. Overall, it can beconcluded that charge motion control is an effective way toenhance the fuel-air mixing and hence to improve the engineperformance.

REFERENCES1. Mittal, M., Hung, D.L.S., Zhu, G. and Schock, H.J., “AStudy of Fuel Impingement Analysis on In-Cylinder Surfacesin a Direct-Injection Spark-Ignition Engine with Gasoline andEthanol-Gasoline Blended Fuels,” SAE Technical Paper2010-01-2153, 2010, doi:10.4271/2010-01-2153.

2. Hung, D.L.S., Zhu, G., Winkelman, J.R., Stuecken, T.,Schock, H., and Fedewa, A., “A High Speed FlowVisualization Study of Fuel Spray Pattern Effect on MixtureFormation in a Low Pressure Direct Injection GasolineEngine,” SAE Technical Paper 2007-01-1411, 2007, doi:10.4271/2007-01-1411.

3. Mittal, M., and Schock, H.J., 2010, “A study of cycle-to-cycle variations and the influence of charge motion controlon in-cylinder flow in an I.C. engine,” ASME Journal ofFluids Engineering, 132(5), 051107, pp. 1-8.

4. Clarke, J. R., and Stein, R. A., 1999, “Internal CombustionEngine With Variable Camshaft Timing, Charge MotionControl Valve, and Variable Air/Fuel Ratio,” U.S. Patent No.5,957,096.

5. Li, Y., Liu, S., Shi, S., and Xu, Z., “Effect of the SwirlControl Valve on the In-Cylinder Air Motion in a Four-ValveSI Engine,” SAE Technical Paper 2000-01-2058, 2000, doi:10.4271/2000-01-2058.6. Kim, H., Yoon, S., Xie, X. B., Lai, M. C., Quelhas, S.,Boyd, R., Kumar, N., and Moran, C., “Effects of InjectionTimings and Intake Port Flow Control on the In-CylinderWetted Fuel Footprints During PFI Engine Startup Process,”SAE Technical Paper 2005-01-2082, 2005, doi:10.4271/2005-01-2082.7. Lee, D. and Heywood, J. B., “Effects of Charge MotionControl During Cold Start of SI Engines,” SAE TechnicalPaper 2006-01-3399, 2006, doi:10.4271/2006-01-3399.8. Rassweiler, G. M. and Withrow, L., “Motion Pictures ofEngine Flames Correlated with Pressure Cards,” SAETechnical Paper 380139, 1938, doi:10.4271/380139.9. Mittal, M., Zhu, G., and Schock, H.J., 2009, “Fast massfraction burned calculation using net pressure method forreal-time applications,” Proc. IMechE, Part D: J. AutomobileEngineering, 223(3), pp. 389-394.10. Aleiferis, P.G., Malcolm, J.S., Todd, A.R., Cairns, A.,and Hoffmann, H., “An Optical Study of Spray Developmentand Combustion of Ethanol, Iso-Octane and Gasoline Blendsin a DISI Engine,” SAE Technical Paper 2008-01-0073,2008, doi:10.4271/2008-01-0073.



ACKNOWLEDGMENTSThis work was supported in part by the U.S. Department ofEnergy under Grant DE-FC26-07NT43275.

DEFINITIONS/ABBREVIATIONSλ

Relative air-to-fuel ratio

φFuel-to-air equivalence ratio

180° BTDC180 crank angle degrees before TDC of compression

25.2° AST25.2 crank angle degrees after spark timing

BDCBottom dead center

BTDCBefore top dead center

CADCrank angle degree

CMCCharge motion control

CMCVCharge motion control valve

DIDirect-injection

DISIDirect-injection spark-ignition

HPDIHigh-pressure direct-injection

IMEPIndicated mean effective pressure

MAPManifold absolute pressure

MFBMass fraction burned

RPMRevolutions per minute

SOIStart of injection

STSpark timing

CONTACT INFORMATIONAuthor for correspondence:

Mayank Mittal, PhDDepartment of Mechanical EngineeringMichigan State UniversityEast Lansing, MI - 48824, [email protected]

TDCTop dead center

VCTVariable camshaft timing



http://www.sae.org/technical/papers/2010-01-2153

http://dx.doi.org/10.4271/2010-01-2153


http://dx.doi.org/10.4271/2007-01-1411


http://dx.doi.org/10.4271/2000-01-2058


http://dx.doi.org/10.4271/2005-01-2082


http://dx.doi.org/10.4271/2006-01-3399

http://www.sae.org/technical/papers/380139

http://dx.doi.org/10.4271/380139


http://dx.doi.org/10.4271/2008-01-0073

mailto:[email protected]

study the effects of charge motion control on fuel published … · 2018-06-12 · abstract an...

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