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Flame propagation model for a rotary Atkinson cycle SI engine

  • Mohammad Hassan Shojaeefard
  • Mojtaba Keshavarz
Article
  • 193 Downloads

Abstract

The rotary Atkinson cycle engine includes two modes of combustion: combustion initiation and propagation in ignition chamber and then flame jet entrainment and propagation in expansion chamber. The turbulent flame propagation model is a predictive model for SI engines which could be developed for this type of combustion for the rotary Atkinson engine similar to the congenital engine with pre-chamber; in split combustion chamber SI engines, small amount of fuel is burned in pre-chamber while the fuel burned in ignition chamber of rotary Atkinson cycle is considerable. In this study a mathematical modeling of spherical flame propagation inside ignition chamber and new combined conical flame and spherical flame propagation model of a new two-stroke Atkinson cycle SI engine will be presented. The mathematical modeling is carried out using two-zone combustion analysis and the model also is validated against experimental tests and compared with previous study using non-predictive Weibe function model.

Keywords

Turbulent flame Jet entrainment Internal combustion engine Rotary engine 

Nomenclature

A

Area

C

model calibration factor

Cd

discharge coefficient

Ce

entrainment coefficient

fxp

flame expansion factor

e

the rotor offset

fd

dilution multiplier

k

turbulent kinetic energy

Kr

turbulent speed multiplier

L

position of moving piston

Ljet

jet length in expansion chamber

le

turbulent length scale

lt

unburned eddy size

m

mass

mass flow rate

P

pressure

rc

imflamation radius

rf

flame radius at ignition chamber

ri

initial flame kernel radius

Re

Reynolds number

Rc

trailing rotor radius

Rm

main rotor radius

Rf

flame radius at expansion chamber

Rg

gas constant

S

Flame speed

t

time

T

Temperature

U

velocity

Ū

average velocity

u'

turbulent intensity

V

volume

x

fraction of burned masses

xr

residual gases fraction

γ

the specific heat ratio of the gas

δ

expansion chamber height

θ

the main rotor rotation angle

φ

equivalence ratio

ρ

density

μ

dynamic viscosity

τb

characteristic burne time

Subscripts

0

condition at start of closed cycle

A

upstream

b

burned

c

conical

Cr

critical

e

entrained

ent

entrainment

exp

expansion chamber

F

flame

in

inlet

int

intake

ign

ignition chamber

L

laminar

s

Spherical

T

turbulent

u

unburned

w

wall effect

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References

  1. Ahmed, I. (2014). Simulation of Turbulent Flames Relevant to Spark-ignition Engines. Ph. D. Dissertation. University of Cambridge. Cambridge, UK.Google Scholar
  2. Auer, M. and Wachtmeister, G. (2009). Phenomenological models for pre-calculation of the combustion in gas engines. MTZ Worldwide 70, 6, 52–59.CrossRefGoogle Scholar
  3. Bayraktar, H. and Durgun, O. (2005). Investigating the effects of LPG on spark ignition engine combustion and performance. Energy Conversion and Management 46, 13-14, 2317–2333.CrossRefGoogle Scholar
  4. Beretta, G. P., Rashidi, M. and Keck, J. C. (1983). Turbulent flame propagation and combustion in spark ignition engines. Combustion and Flame, 52, 217–245.CrossRefGoogle Scholar
  5. Boretti, A. and Scalzo, J. (2011). Exploring the advantages of atkinson effects in variable compression ratio turbo GDI engines. SAE Paper No. 2011-01-0367.CrossRefGoogle Scholar
  6. Danieli, G. A., Keck, J. C. and Heywood, J. B. (1978). Experimental and theoretical analysis of wankel engine performance. SAE Paper No. 780416.CrossRefGoogle Scholar
  7. Dong, G., Han, X., Stobart, R. and Lu, S. (2013). Dynamic analysis of the libralato thermodynamic cycle based rotary engine. SAE Paper No. 2013-01-1620.CrossRefGoogle Scholar
  8. Hernandez, J., Lapuerta, M. and Serrano, C. (2005). Estimation of the laminar flame speed of producer gas from biomass gasification. Energy and Fuels 19, 5, 2172–2178.CrossRefGoogle Scholar
  9. Heywood, J. B. (1988). Internal Combustion Engine Fundamentals. 1st edn. McGraw-Hill. Singapore.Google Scholar
  10. Hiereth, H. and Preninger, P. (2003). Charging the Internal Combustion Engines. 1st edn. Springer-Verlag Vienna. Vienna, Austria.Google Scholar
  11. Hires, S. D., Tabaczynski, R. J. and Novak, J. M. (1978). The prediction of ignition delay and combustion intervals for homogenous charge spark ignition engine. SAE Paper No. 780232.Google Scholar
  12. Lämmle, C. (2005). Numerical and Experimental Study of Flame Propagation and Knock in a Compressed Natural Gas Engine. Ph. D. Dissertation. Swiss Federal Institute of Technology Zurich. Zurich, Switzerland.Google Scholar
  13. Papagiannakis, R. G., Hountalas, D. T. and Rakopoulos, C. D. (2007). Theoretical study of the effects of pilot fuel quantity and its injection timing on the performance and emissions of a dual fuel diesel engine. Energy Conversion and Management 48, 11, 2951–2961.CrossRefGoogle Scholar
  14. Qian, T., Zuo, C., Tan, J. and Xu, H. (2005). Combustion and emissions in a spark-ignition engine fueled with coal-bed gas–Modeling and experimental results. SAE Paper No. 2005-01-3804.CrossRefGoogle Scholar
  15. Shojaeefard, M. and Keshavarz, M. (2015). Mathematical modeling of the complete thermodynamic cycle of a new atkinson cycle gas engine. Applied Thermal Engineering, 91, 866–874.CrossRefGoogle Scholar
  16. Tagalian, J. and Heywood, J. B. (1986). Flame initiation in a spark-ignition engine. Combustion and Flame, 64, 243–246.CrossRefGoogle Scholar
  17. Thomas, G. (2013). Thomas’ Calculus Early Transcendentals. 13rd edn. Pearson. USA.Google Scholar
  18. Watanabe, S., Koga, H. and Kono, S. (2006). Research on extended expansion general-purpose engine: Theoretical analysis of multiple linkage system and improvement of thermal efficiency. SAE Paper No. 2006-32-0101.Google Scholar
  19. Zuo, T. and Zhao, K. (1997). A quasidimensional model of SI natural gas engines with prechamber. SAE Paper No. 972994.CrossRefGoogle Scholar

Copyright information

© The Korean Society of Automotive Engineers and Springer-Verlag GmbH Germany 2018

Authors and Affiliations

  • Mohammad Hassan Shojaeefard
    • 1
  • Mojtaba Keshavarz
    • 2
  1. 1.Department of Mechanical EngineeringIran University of Science and TechnologyTehranIran
  2. 2.Department of Automotive EngineeringIran University of Science and TechnologyTehranIran

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