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Modelling a Duaul-fuelled Multi-cylinder HCCI Engine Using a PDF based Engine Cycle Simulator

Behave, Amit; Kraft, Markus; Montorsi, Luca and Mauss, Fabian LU (2004) In SAE Technical Paper Series
Abstract
Operating the HCCI engine with dual fuels with a large difference in auto-ignition characteristics (octane number) is one way to control the HCCI operation. The effect of octane number on combustion, emissions and engine performance in a 6-cylinder SCANIA truck engine, fuelled with n-heptane and isooctane, and running in HCCI mode, are investigated numerically and compared with measurements taken from Olsson et al. To correctly simulate the HCCI engine operation, we implement a probability density function (PDF)-based stochastic reactor model (including detailed chemical kinetics and accounting for inhomogeneities in composition and temperature) coupled with GT-POWER, a 1-D fluid-dynamics-based engine cycle simulator. Such a coupling... (More)
Operating the HCCI engine with dual fuels with a large difference in auto-ignition characteristics (octane number) is one way to control the HCCI operation. The effect of octane number on combustion, emissions and engine performance in a 6-cylinder SCANIA truck engine, fuelled with n-heptane and isooctane, and running in HCCI mode, are investigated numerically and compared with measurements taken from Olsson et al. To correctly simulate the HCCI engine operation, we implement a probability density function (PDF)-based stochastic reactor model (including detailed chemical kinetics and accounting for inhomogeneities in composition and temperature) coupled with GT-POWER, a 1-D fluid-dynamics-based engine cycle simulator. Such a coupling proves to be ideal for the understanding of the combustion phenomenon as well as the gas dynamics processes intrinsic to the engine cycle. The convective heat transfer in the engine cylinder is modeled as a stochastic jump process and accounts for the fluctuations and fluid-wall interaction effects. Curl's coalescence-dispersion model is used to describe turbulent mixing. A good agreement is observed between the predicted values and measurements for in-cylinder pressure, auto-ignition timing and CO, HC as well as NOx emissions for the base case. The advanced PDF-based engine cycle simulator clearly outperforms the widely used homogeneous model-based full cycle engine simulator. The trends in combustion characteristics such as ignition crank angle degree and combustion duration with respect to varying octane numbers are predicted well as compared to measurements. The integrated model provides reliable predictions for in-cylinder temperature, CO, HC as well as NOx emissions over a wide range of octane numbers studied. (Less)
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Contribution to specialist publication or newspaper
publication status
published
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categories
Popular Science
in
SAE Technical Paper Series
issue
No 2004-01-0561
ISSN
0148-7191
language
English
LU publication?
yes
id
5012f4d9-b25d-4350-8362-36fdcb364e55 (old id 1293859)
date added to LUP
2009-02-10 14:19:15
date last changed
2016-04-16 06:36:48
@misc{5012f4d9-b25d-4350-8362-36fdcb364e55,
  abstract     = {Operating the HCCI engine with dual fuels with a large difference in auto-ignition characteristics (octane number) is one way to control the HCCI operation. The effect of octane number on combustion, emissions and engine performance in a 6-cylinder SCANIA truck engine, fuelled with n-heptane and isooctane, and running in HCCI mode, are investigated numerically and compared with measurements taken from Olsson et al. To correctly simulate the HCCI engine operation, we implement a probability density function (PDF)-based stochastic reactor model (including detailed chemical kinetics and accounting for inhomogeneities in composition and temperature) coupled with GT-POWER, a 1-D fluid-dynamics-based engine cycle simulator. Such a coupling proves to be ideal for the understanding of the combustion phenomenon as well as the gas dynamics processes intrinsic to the engine cycle. The convective heat transfer in the engine cylinder is modeled as a stochastic jump process and accounts for the fluctuations and fluid-wall interaction effects. Curl's coalescence-dispersion model is used to describe turbulent mixing. A good agreement is observed between the predicted values and measurements for in-cylinder pressure, auto-ignition timing and CO, HC as well as NOx emissions for the base case. The advanced PDF-based engine cycle simulator clearly outperforms the widely used homogeneous model-based full cycle engine simulator. The trends in combustion characteristics such as ignition crank angle degree and combustion duration with respect to varying octane numbers are predicted well as compared to measurements. The integrated model provides reliable predictions for in-cylinder temperature, CO, HC as well as NOx emissions over a wide range of octane numbers studied.},
  author       = {Behave, Amit and Kraft, Markus and Montorsi, Luca and Mauss, Fabian},
  issn         = {0148-7191},
  language     = {eng},
  number       = {No 2004-01-0561},
  series       = {SAE Technical Paper Series},
  title        = {Modelling a Duaul-fuelled Multi-cylinder HCCI Engine Using a PDF based Engine Cycle Simulator},
  year         = {2004},
}