0
Research Papers: Internal Combustion Engines

Comparison of Diesel Engine Efficiency and Combustion Characteristics Between Different Bore Engines

[+] Author and Article Information
Jue Li

Department of Mechanical Engineering,
Texas A&M University,
3123 TAMU,
College Station, TX 77843-3123

Timothy J. Jacobs

Department of Mechanical Engineering,
Texas A&M University,
3123 TAMU,
College Station, TX 77843-3123
e-mail: tjjacobs@tamu.edu

Tushar Bera

Shell Global Solutions (US), Inc.,
Houston TX 77082
e-mail: Tushar.Bera@shell.com

Michael A. Parkes

Shell Research Limited,
London SE1 7NA, UK
e-mail: Michael.Parkes@shell.com

Contributed by the IC Engine Division of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received June 20, 2017; final manuscript received February 20, 2018; published online June 25, 2018. Assoc. Editor: David L. S. Hung.

J. Eng. Gas Turbines Power 140(10), 102807 (Jun 25, 2018) (13 pages) Paper No: GTP-17-1225; doi: 10.1115/1.4040092 History: Received June 20, 2017; Revised February 20, 2018

This study investigates the effects of engine bore size on diesel engine performance and combustion characteristics, including in-cylinder pressure, ignition delay, burn duration, and fuel conversion efficiency, using experiments between two diesel engines of different bore sizes. This study is part of a larger effort to discover how fuel property effects on combustion, engine efficiency, and emissions may change for differently sized engines. For this specific study, which is centered only on diagnosing the role of engine bore size on engine efficiency for a typical fuel, the engine and combustion characteristics are investigated at various injection timings between two differently sized engines. The two engines are nearly identical, except bore size, stroke length, and consequently displacement. Although most of this diagnosis is done with experimental results, a one-dimensional model is also used to calculate turbulence intensities with respect to geometric factors; these results help to explain observed differences in heat transfer characteristics of the two engines. The results are compared at the same brake mean effective pressure (BMEP) and show that engine bore size has a significant impact on the indicated efficiency. It is found that the larger bore engine has a higher indicated efficiency than the smaller displaced engine. Although the larger engine has higher turbulence intensities, longer burn durations, and higher exhaust temperature, the lower surface area to volume ratio and lower reaction temperature leads to lower heat losses to the cylinder walls. The difference in the heat loss to the cylinder walls between the two engines is found to increase with increasing engine load. In addition, due to the smaller volume-normalized friction loss, the larger sized engine also has higher mechanical efficiency. In the net, since the brake efficiency is a function of indicated efficiency and mechanical efficiency, the larger sized engine has higher brake efficiency with the difference in brake efficiency between the two engines increasing with increasing engine load. In the interest of efficiency, larger bore designs for a given displacement (i.e., shorter strokes or few number of cylinders) could be a means for future efficiency gains.

FIGURES IN THIS ARTICLE
<>
Copyright © 2018 by ASME
Your Session has timed out. Please sign back in to continue.

References

Altin, İ. , Sezer, İ. , and Bilgin, A. , 2008, “ Effects of the Stroke/Bore Ratio on the Performance Parameters of a Dual-Spark-Ignition (DSI) Engine,” Energy Fuels, 23(4), pp. 1825–1831. [CrossRef]
Wittek, K. , Tiemann, C. , and Pischinger, S. , 2009, “ Two-Stage Variable Compression Ratio With Eccentric Piston Pin and Exploitation of Crank Train Forces,” SAE Int. J. Engines, 2(1), pp. 1304–1313. [CrossRef]
Bilgin, A. , 2002, “ Geometric Features of the Flame Propagation Process for an SI Engine Having Dual-Ignition System,” Int. J. Energy Res., 26(11), pp. 987–1000. [CrossRef]
Kleeberg, H. , Tomazic, D. , Dohmen, J. , Wittek, K. , and Balazs, A. , 2013, “ Increasing Efficiency in Gasoline Powertrains With a Two-Stage Variable Compression Ratio (VCR) System,” SAE Paper No. 2013-01-0288.
Filipi, Z. , and Assanis, D. , 2000, “ The Effect of the Stroke-to-Bore Ratio on Combustion, Heat Transfer and Efficiency of a Homogeneous Charge Spark Ignition Engine of Given Displacement,” Int. J. Engine Res., 1(2), pp. 191–208. [CrossRef]
Thornhill, D. , Douglas, R. , Kenny, R. , and Fitzsimons, B. , 1999, “ An Experimental Investigation into the Effect of Bore/Stroke Ratio on a Simple Two-Stroke Cycle Engine,” SAE Paper No. 1999-01-3342.
Aceves, S. , Flowers, D. , Espinosa-Loza, F. , Martinez-Frias, J. , Robert, W. D. , Christensen, M. , Johansson, B. , and Hessel P. R. , 2002, “ Piston-Liner Crevice Geometry Effect on HCCI Combustion by Multi-Zone Analysis,” SAE Paper No. 2002-01-2869.
Hyvönen, J. , Wilhelmsson, C. , and Johansson, B. , 2006, “ The Effect of Displacement on Air-Diluted Multi-Cylinder HCCI Engine Performance,” SAE Paper No. 2006-01-0205.
Dong, J. , Ouyang, L. , Zhou, Y. , and Pan, Q. , 2012, “ Study on Variable Combustion Chamber (VCC) Engines,” SAE Paper No. 2012-01-1607.
Dong, J. , Ouyang, L. , Zhou, Y. , He, Y. , and Pan, Q. , 2013, “ Effect of Design Features on Dynamic Characteristics of VCC Piston for I. C. Engine,” SAE Int. J. Engines, 6(1), pp. 209–216. [CrossRef]
Lancaster, D. R. , Krieger, R. B. , and Lienesch, J. H. , 1975, “ Measurement and Analysis of Engine Pressure Data,” SAE Trans., 84, pp. 155–172.
Stricker, K. , Kocher, L. , Koeberlein, Ed. , Alstine, D. V. , and Shaver, G. M. , 2012, “ Estimation of Effective Compression Ratio for Engines Utilizing Flexible Intake Valve Actuation,” Proc. Inst. Mech. Eng., Part D, 226(8), pp. 1001–1015. [CrossRef]
Modiyani, R. , Kocher, L. , Van Alstine, D. G. , Koeberlein, E. , Stricker, K. , Meckl, P. , and Shaver, G. , 2011, “ Effect of Intake Valve Closure Modulation on Effective Compression Ratio and Gas Exchange in Turbocharged Multi-Cylinder Engines Utilizing EGR,” Int. J. Engine Res., 12(6), pp. 617–631. [CrossRef]
Gamma Technologies, 2012, “ GT-Suit Engine Performance Application Manual,” Gamma Technologies, Inc., Westmont, IL, p. 106.
Hawley, J. G. , Wallace, F. J. , Cox, A. , Horrocks, R. W. , and Bird, G. L. , 1999, “ Reduction of Steady State NOx Levels From an Automotive Diesel Engine Using Optimized VGT/EGR Schedules,” SAE Paper No. 1999-01-0835.
Patterson, M. , Kong, S. , Hampson, G. , and Reitz, R. , 1994, “ Modeling the Effects of Fuel Injection Characteristics on Diesel Engine Soot and NOx Emissions,” SAE Paper No. 940523.
Jung, D. , and Assanis, D. N. , 2001, “ Multi-Zone DI Diesel Spray Combustion Model for Cycle Simulation Studies of Engine Performance and Emissions,” SAE Paper No. 2001-01-1246.
Xue, X. , and Caton, J. A. , 2012, “ Detailed Multi-Zone Thermodynamic Simulation for Direct-Injection Diesel Engine Combustion,” Int. J. Engine Res., 13(4), pp. 340–356. [CrossRef]
Depcik, C. , Jacobs, T. , Hagena, J. , and Assains, D. , 2007, “ Instructional Use of a Single-Zone, Premixed Charge, Spark-Ignition Engine Heat Release Simulation,” Int. J. Mech. Eng. Educ., 35(1), pp. 1–31. [CrossRef]
Woschni, G. , 1967, “ A Universally Applicable Equation for the Instantaneous Heat Transfer Coefficient in the Internal Combustion Engine,” SAE Paper No. 670931.
Patton, K. J. , Nitschke, R. G. , and Heywood, J. B. , 1989, “ Development and Evaluation of a Friction Model for Spark-Ignition Engines,” SAE Paper No. 890836.

Figures

Grahic Jump Location
Fig. 1

Injection profiles between the two engines at (a) low-load and (b) medium-load conditions. Each condition is at 1500 rev/min engine speed and injection timing = −9 deg ATDC.

Grahic Jump Location
Fig. 2

In-cylinder pressure for the two studied engines of different displacements and S/B ratios at a motored condition

Grahic Jump Location
Fig. 3

(a) In-cylinder pressure, (b) heat release rate at low-load condition, (c) in-cylinder pressure, and (d) heat release rate at medium-load condition as functions of engine crank angle for experimental (EXP) and simulated (SIM) data of the medium duty

Grahic Jump Location
Fig. 4

(a) In-cylinder pressure, (b) heat release rate at low-load condition, (c) in-cylinder pressure, and (d) heat release rate at medium-load condition as functions of engine crank angle for experimental (EXP) and simulated (SIM) data of the light-duty

Grahic Jump Location
Fig. 5

Comparison of brake fuel conversion efficiency between both engines at (a) low-load and (b) medium-load conditions as functions of injection timing corresponding to 95% confidence

Grahic Jump Location
Fig. 6

Comparison of net indicated thermal efficiency between the two engines at (a) low-load and (b) medium-load conditions as functions of injection timing corresponding to 95% confidence

Grahic Jump Location
Fig. 7

(a) Ignition delay, (b) mixture temperature at time of injection, and (c) air/fuel (A/F) ratio for the two studied engines at low- and medium-load conditions, as functions of injection timing corresponding to 95% confidence

Grahic Jump Location
Fig. 8

Burned mass faction profiles between the two engines at (a) low-load and (b) medium-load conditions at the same CA50 location (effected through different injection timings)

Grahic Jump Location
Fig. 9

Simulated turbulence intensity for the two studied engines at (a) low-load and (b) medium-load conditions, 11.5 deg CA ATDC CA50 location

Grahic Jump Location
Fig. 10

Calculated mixture gas temperature between the two engines at (a) low-load and (b) medium-load conditions, 11.5 deg CA ATDC CA50 location (effected through different injection timings)

Grahic Jump Location
Fig. 11

Comparison of heat rejection to cylinder wall between two engines at (a) low-load and (b) medium-load conditions as functions of injection timing corresponding to 95% confidence

Grahic Jump Location
Fig. 12

Comparison of combustion efficiency between both engines at (a) low-load and (b) medium-load conditions as functions of injection timing corresponding to 95% confidence

Grahic Jump Location
Fig. 13

(a) Mechanical efficiency, (b) friction loss, and (c) PMEP as a fraction of indicated power for both engines at low- and medium-load conditions as functions of injection timing corresponding to 95% confidence

Tables

Errata

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In