This content is not included in
your SAE MOBILUS subscription, or you are not logged in.
Investigations of the Effect of Ambient Condition on SACI Combustion Range
Technical Paper
2015-01-0828
ISSN: 0148-7191, e-ISSN: 2688-3627
Annotation ability available
Sector:
Language:
English
Abstract
HCCI (Homogeneous Charge Compression Ignition) has the potential for significant fuel efficiency improvements and low engine-out emissions but a major limitation is its relatively small operating range, limited by pressure rise rate at high loads and cyclic variability and incomplete combustion at low loads. Spark Assisted Compression Ignition (SACI) can extend the operating range of HCCI, but since SACI includes both flame propagation and auto-ignition, it experiences higher cyclic variance than HCCI combustion and phasing control can be challenging. This paper investigates the effects of environmental conditions on SACI combustion.
The first part of the paper investigates whether CA50 (the location of 50% heat release and the most commonly used combustion parameter for describing combustion phasing) is the best metric to describe combustion phasing and facilitate its control. CA50 and four other combustion phasing metrics are evaluated and compared in this study. To perform this evaluation, IMEP (Indicated Mean Effective Pressure) and RI (Ringing Intensity), key combustion outputs that are directly perceived by a driver, are plotted versus each combustion control parameter and the physical correlation between each parameter and IMEP and RI are examined for individual cycles in the SACI combustion mode. It is concluded that CA50 is the best metric for SACI combustion control because CA50 shows the best correlation with IMEP and RI and does not have high computational requirements.
The second and main part of the paper investigates the impact of environmental conditions (i.e. intake air temperature and humidity) on CA50 and the allowable range of CA50 in a production-feasible SACI engine. The allowable operating range is defined by a RI of 5 bar/degree and a coefficient of variance (COV) of IMEP of 4%. Higher ambient temperature is found to advance combustion phasing, while higher humidity is found to retard combustion phasing. The early and late combustion phasing bounds of the operable range are observed to undergo a similar shift.
Recommended Content
Authors
Citation
Mendrea, B., Chang, Y., Akkus, Y., Sterniak, J. et al., "Investigations of the Effect of Ambient Condition on SACI Combustion Range," SAE Technical Paper 2015-01-0828, 2015, https://doi.org/10.4271/2015-01-0828.Also In
References
- Najt , P. and Foster , D. Compression-Ignited Homogeneous Charge Combustion SAE Technical Paper 830264 1983 10.4271/830264
- Juttu , S. , Thipse , S. , Marathe , N. , and Gajendra Babu , M. Homogeneous Charge Compression Ignition (HCCI): A New Concept for Near Zero NOx and Particulate Matter (PM) from Diesel Engine Combustion SAE Technical Paper 2007-26-020 2007 10.4271/2007-26-020
- Thring , R. Homogeneous-Charge Compression-Ignition (HCCI) Engines SAE Technical Paper 892068 1989 10.4271/892068
- Yun , H. , Wermuth , N. , and Najt , P. Extending the High Load Operating Limit of a Naturally-Aspirated Gasoline HCCI Combustion Engine SAE Int. J. Engines 3 1 681 699 2010 10.4271/2010-01-0847
- Temel , V. and Sterniak , J. Characterization of SACI Combustion for Use in Model Based Controls SAE Technical Paper 2014-01-1289 2014 10.4271/2014-01-1289
- Brehob , D.D. Humidity-based combustion control in a multiple combustion mode engine U.S. Patent 7,363,911 April 29 2008
- Shibata , G. and Urushihara , T. The Interaction Between Fuel Chemicals and HCCI Combustion Characteristics Under Heated Intake Air Conditions SAE Technical Paper 2006-01-0207 2006 10.4271/2006-01-0207
- Kubesh , J. and Podnar , D. Humidity Effects and Compensation in a Lean Burn Natural Gas Engine SAE Technical Paper 971706 1997 10.4271/971706
- Rakopoulos , C.D. Ambient temperature and humidity effects on the performance and nitric oxide emission of spark ignition engined vehicles in Athens/Greece Solar & Wind Technology 5 3 1988 315 320
- Pickett , L.M. , Siebers , D.L. Soot in diesel fuel jets: effects of ambient temperature, ambient density, and injection pressure Combustion and Flame 138 1 2004 114 135
- Whitehouse , N.D. , Stotter , Janota , M.S. Estimating the effects of altitude, ambient temperature and turbocharger match on engine performance Proceedings of the Institution of Mechanical Engineers 178 1 1963 483 500
- Andreae , M. , Cheng , W. , Kenney , T. , and Yang , J. Effect of Air Temperature and Humidity on Gasoline HCCI Operating in the Negative-Valve-Overlap Mode SAE Technical Paper 2007-01-0221 2007 10.4271/2007-01-0221
- Yang , D. , Li , Z.P. , Hong , O.Y. Effects of humidity, temperature and slow oxidation reactions on the occurrence of gasoline-air explosions Journal of Fire Protection Engineering 23 3 2013 226 238