Measurement of Residual Gas Fraction using a Fast Response NO Sensor

Ford, Richard G.; Collings, Nick

doi:10.4271/1999-01-0208

Cited by 27 publications

(4 citation statements)

References 12 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Recent developments in gas sampling hardware [17] and fastresponse emissions analysers [18][19][20] have created new opportunities for experimental investigation of transient engine operation. The capabilities of the instrumentation for direct in-cylinder gas sampling [21][22][23][24][25][26][27][28], exhaust port measurements [28][29][30][31][32][33][34][35][36][37], or both [38][39][40][41], have been demonstrated. The majority of these studies have used spark-ignition engines or focused on only one constituent of the cylinder charge, such as residual fraction.…”

Section: Introductionmentioning

confidence: 99%

Cycle-resolved measurements of in-cylinder constituents during diesel engine transients and insight into their impact on emissions

Hagena

Assanis

Filipi

2011

Proceedings of the Institution of Mechanical Engineers, Part D:

View full text Add to dashboard Cite

Diesel engine transients, in particular the rapid increase of load from idle, lead to significant excursions of operating parameters from normal, steady-state operation. A typical transient event is initiated by a sudden increase of fuelling followed by a turbo lag period. The trajectories of key parameters, such as boost pressure, air/fuel ratio, and amount of residual in the cylinder, depend on the complex interplay between the control system behaviour, actuator response, and time scales of physical processes. The end result is a significant deviation of the combustion event and emission formation. For example, it has been shown that transient spikes of soot may be responsible for up to half of total particulate emissions during a city driving cycle. The present paper introduces an experimental technique to quantify cycle-resolved pre-combustion in-cylinder constituents during transient engine operation and uses measurements to generate insight into mechanisms that cause increased emissions during a diesel engine transient event. A 6.0-litre V-8 diesel engine is instrumented for fuel injector needle lift and injection pressure measurements, cylinder pressure, simultaneous fast measurements of CO2 concentrations in the exhaust and in the cylinder, and fast measurements of NO and particulate spectrum. Analytical techniques are introduced to process measurements and determine cycle-resolved mass of fuel, air, and stoichiometric combustion products, thus providing insight into reasons for significant variations of emission during the transient. The technique is utilized to study engine behaviour over an FTP-72 driving cycle.

show abstract

Section: Introductionmentioning

confidence: 99%

Cycle-resolved measurements of in-cylinder constituents during diesel engine transients and insight into their impact on emissions

Hagena

Assanis

Filipi

2011

Proceedings of the Institution of Mechanical Engineers, Part D:

View full text Add to dashboard Cite

show abstract

“…This residual gas fraction is supported to some extent by measurements of residual gas levels presented by Miller et al [19]. These measurements were taken in a modern four- [20] show values above 15 per cent at an inlet manifold pressure of 70 kPa and 1000 r/min. The assumption of a 10 per cent residual molar fraction may thus be an underestimation in the case of the engine used here.…”

Section: Experimental Equipment and Methodsmentioning

confidence: 60%

A study of the influence of exhaust gas recirculation and stoichiometry on the heat release in the end-gas prior to knock using rotational coherent anti-Stokes-Raman spectroscopy thermometry

Grandin

Denbratt

Bood³

et al. 2002

International Journal of Engine Research

View full text Add to dashboard Cite

Heat release in the end-gas prior to autoignition was investigated using different experimental methods including transducers for heat flux and pressure as well as rotational coherent anti-Stokes-Raman spectroscopy, which is a laser-based method for non-intrusive instantaneous thermometry of the gas. The time history was examined in the cases of mixtures of various stoichio-metries, where some were diluted with exhaust gas recir-culation (EGR). The measured temperature history was compared with the isentropic temperature calculated from the cylinder pressure trace. This comparison revealed a difference in heat release from low-temperature reactions in the end-gas for the various mixtures tested at a constant indicated mean effective pressure and a fixed position of 50 per cent burnt charge. It is shown that lean mixtures tend to exhibit the highest knock intensity, mainly due to a decrease in specific heat, as compared to the richer mixtures, which result in an earlier knock onset and as a consequence higher knock intensity. Furthermore, the comparison of temperatures indicates that the rich mixtures have a high heat release from low-temperature chemistry, which to some extent negates the higher specific heat of the charge. As a consequence, a slight enrichment of the charge can lead to higher knock intensity in comparison with a stoichiometric mixture. In spite of the lower specific heat of the charge when a stoichiometric charge was diluted with cooled EGR, these mixtures showed a very low tendency to knock.

show abstract

“…The experimental measurement methods for RGM (or fraction) are either pressure [15][16][17] or emissions based. [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] Pressure-based methods are relatively less expensive than emissionbased methods, but they require a combination of accurate modeling and experimental measurements to produce accurate results. Emission-based methods combine a tracer species and a measurement technique.…”

Section: Experimental Setup and Data Collectionmentioning

confidence: 99%

Control-oriented residual gas mass prediction for spark ignition engines

Wang

Prucka

et al. 2014

International Journal of Engine Research

View full text Add to dashboard Cite

Trapped residual gas mass is an important physical factor that influences combustion phasing and variation, fuel consumption, and air mass prediction for fuel control. There are currently no mass-production sensors available to directly measure in-cylinder residual gas mass, so prediction models must be utilized for control. Residual gas content of the cylinder can be difficult to directly model for control purposes because it involves complex flows during gas exchange that are driven by fluctuating pressures in the intake and exhaust systems. Capturing these effects in an accurate manner generally requires high model complexity and computational effort outside of the capability of most production intent engine controllers. This paper presents a semi-physics-based control oriented residual gas mass (RGM) prediction method. The RGM model is based on Bernoulli’s principle and considers engine operating conditions, valve timing and geometry, and piston motion effects. Moreover, to more accurately estimate the burned gas back flow, this model captures gas wave dynamic effects in intake and exhaust manifold pressures. The model is described in detail and its prediction accuracy is compared to that of a high fidelity simulation that utilizes experimentally measured crank angle resolved intake, exhaust, and cylinder pressures as boundary conditions. The new model is incorporated into a rapid-prototype control system for real-time operation during transient and steady-state engine operation. The results show that the proposed RGM model provides real-time predictions within 1.9-2.3% RGF, creating relative estimation errors in the range of 10-24%, and is capable of running real-time for engine control.

show abstract

Measurement of Residual Gas Fraction using a Fast Response NO Sensor

Cited by 27 publications

References 12 publications

Cycle-resolved measurements of in-cylinder constituents during diesel engine transients and insight into their impact on emissions

Cycle-resolved measurements of in-cylinder constituents during diesel engine transients and insight into their impact on emissions

A study of the influence of exhaust gas recirculation and stoichiometry on the heat release in the end-gas prior to knock using rotational coherent anti-Stokes-Raman spectroscopy thermometry

Control-oriented residual gas mass prediction for spark ignition engines

Contact Info

Product

Resources

About