A Control Oriented SI and HCCI Hybrid Combustion Model for Internal Combustion Engines

Author(s):  
Xiaojian Yang ◽  
Guoming G. Zhu ◽  
Zongxuan Sun

The combustion mode transition between SI (spark ignited) and HCCI (Homogeneously Charged Compression Ignition) of an IC (Internal Combustion) engine is challenge due to the thermo inertia of residue gas; and model-based control becomes a necessity. This paper presents a control oriented two-zone model to describe the hybrid combustion that starts with SI combustion and ends with HCCI combustion. The gas respiration dynamics were modeled using mean-value approach and the combustion process was modeled using crank resolved method. The developed model was validated in an HIL (Hardware-In-the-Loop) simulation environment for both steady-state and transient operations in SI, HCCI, and SI-HCCI hybrid combustion modes through the exhaust valve timing control (recompression). Furthermore, cooled external EGR (exhaust gas re-circulation) was used to suppress engine knock and enhance the fuel efficiency. The simulation results also illustrates that the transient control parameters of hybrid combustion is quite different from these in steady state operation, indicating the need of a control oriented SI-HCCI hybrid combustion model for transient combustion control.

Author(s):  
Xavier Tauzia ◽  
Pascal Chesse ◽  
Jean-François Hetet ◽  
Nicolas Thouvenel

During the last decades, pollutant emissions from internal combustion engines used for transportation have become a major concern. Today, not only steady state emissions but also emissions during transients are regulated and have to be studied in order to be reduced. In this paper, we describe a new methodology developed to measure the instantaneous level of gaseous emissions from a internal combustion engine during transients, using an analyzer initially designed for steady state operation. Moreover, a new phenomenological thermodynamical combustion model is proposed in order to compute emissions during transients. The results of these two methods are compared on various transients. The measurement method seems to give good results (except for hydrocarbon (HC) measurements), as long as the speed and load variations are not too fast. Otherwise, the frequency of the analyzer which was used becomes the limiting factor. The new combustion heat release developed to simulate transients, coupled with an existing two-zone model for emission calculations, leads to satisfactory results for CO2 and O2 concentrations and NOx emissions. The agreement with measurements is good for smooth transients and seems promising for faster dynamics. The initial goal was reached, although some improvements are still necessary concerning HC measurements and the fastest transients. These results could be helpful when trying to reduce the amount of pollutant emissions at the exhaust during transients, directly or with after treatment devices.


Author(s):  
Jiang Lu ◽  
Ashwani K. Gupta ◽  
Eugene L. Keating

Abstract Numerical simulation of flow, combustion, heat release rate and pollutants emission characteristics have been obtained using a single cylinder internal combustion engine operating with propane as the fuel. The data are compared with experimental results and show excellent agreement for peak pressure and the rate of pressure rise as a function of crank angle. The results obtained for NO and CO are also found to be in good agreement and are similar to those reported in the literature for the chosen combustion chamber geometry. The results have shown that both the combustion chamber geometry and engine operating parameters affects the flame growth within the combustion chamber which subsequently affects the pollutants emission levels. The code employed the time marching procedure and solves the governing partial differential equations of multi-component chemically reacting fluid flow by finite difference method. The numerical results provide a cost effective means of developing advanced internal combustion engine chamber geometry design that provides high efficiency and low pollution levels. It is expected that increased computational tools will be used in the future for enhancing our understanding of the detailed combustion process in internal combustion engines and all other energy conversion systems. Such detailed information is critical for the development of advanced methods for energy conservation and environmental pollution control.


2019 ◽  
Vol 178 (3) ◽  
pp. 182-186
Author(s):  
Zbigniew SROKA ◽  
Maciej DWORACZYŃSKI

The modification of the downsizing trend of internal combustion engines towards rightsizing is a new challenge for constructors. The change in the displacement volume of internal combustion engines accompanying the rightsizing idea may in fact mean a reduction or increase of the defining swept volume change factors and thus may affect the change in the operating characteristics as a result of changes in combustion process parameters - a research problem described in this publication. Incidents of changes in the displacement volume were considered along with the change of the compression space and at the change of the geometric degree of compression. The new form of the mathematical dependence describing the efficiency of the thermodynamic cycle makes it possible to evaluate the opera-tion indicators of the internal combustion engine along with the implementation of the rightsizing idea. The work demonstrated the in-variance of cycle efficiency with different forms of rightsizing.


2021 ◽  
pp. 146808742110442
Author(s):  
Sebastian Welscher ◽  
Mohammad Hossein Moradi ◽  
Antonino Vacca ◽  
Peter Bloch ◽  
Michael Grill ◽  
...  

Due to increasing climate awareness and the introduction of much stricter exhaust emission legislation the internal combustion engine technology faces major challenges. Although the development and state of technology of internal combustion engines generally reached a very high level over the last years those need to be improved even more. Combining water injection with a diesel engine, therefore, seems to be the next logical step in developing a highly efficient drive train for future mobility. To investigate these potentials, a comprehensive evaluation of water injection on the diesel engine was carried out. This study covers >560 individual operating points on the test bench. The tests were carried out on a single-cylinder derived from a Euro 6d four-cylinder passenger car with the port water injection. Furthermore, a detailed pressure trace analysis (PTA) was performed to evaluate various aspects regarding combustion, emission, etc. The results show no significant effects of water injection on the combustion process, but great potential for NOx reduction. It has been shown that with the use of water injection at water-to-fuel rates of 25%, 50%, and 100%, NOx reduction without deterioration of soot levels can be achieved in 62%, 40%, and 20% of the experiments, respectively. Furthermore, water injection in combination with EGR offers additional reduction in NOx emissions.


Author(s):  
S. Sivrikova ◽  
J. Rojdestvensky ◽  
I. Petrov ◽  
S. Popova

Quality, reliability and fuel efficiency of internal combustion engines (ICE) substantially depend upon optimum choice of lubrication system and tribocontact design and a lubricant liquid. This paper describes a quasistatic method of analysis of ICE lubrication systems for Newtonian and non-Newtonian oils. The method allows for both transient and steady-state conditions.


2019 ◽  
Vol 178 (3) ◽  
pp. 27-37 ◽  
Author(s):  
Denys STEPANENKO ◽  
Zbigniew KNEBA

The mathematical description of combustion process in the internal combustion engines is a very difficult task, due to the variety of phenomena that occurring in the engine from the moment when the fuel-air mixture ignites up to the moment when intake and exhaust valves beginning open. Modeling of the combustion process plays an important role in the engine simulation, which allows to predict in-cylinder pressure during the combustion, engine performance and environmental impact with high accuracy. The toxic emissions, which appears as a result of fuels combustion, are one of the main environmental problem and as a result the air pollutant regulations are increasingly stringent, what makes the investigation of the combustion process to be a relevant task.


Author(s):  
J. Panting ◽  
K. R. Pullen ◽  
R. F. Martinez-Botas

Turbocharging of internal combustion engines is an established technology used for the purpose of increasing both power density and in some cases the cycle efficiency of diesel engines relative to naturally aspirated engines. However, one significant drawback is the inability to match the characteristics of the turbocharger to the engine under full load and also to provide sufficiently good transient response. Under many conditions this results in reduced efficiency and leads to higher exhaust emissions. The design of turbocharger components must be compromised in order to minimize these drawbacks throughout the entire operating range. However, when shaft power can be either added to or subtracted from the turbocharger shaft by means of a direct drive motor-generator, an additional degree of freedom is available to the designer to achieve a better turbocharger-engine matching. Both engine efficiency and transient response can be significantly improved by means of this method, normally described as hybrid turbocharging. This paper describes the results of a theoretical study of the benefits of hybrid turbocharging over a basic turbocharged engine in both steady state and transient operation. The new system and its benefits are described and four different engine-turbocharger systems are analysed in addition to the baseline engine. The main conclusion of the paper is that a significant increase in design point cycle efficiency can be afforded by re-matching the turbocharger components under steady state conditions while at the same time improving full throttle transient performance. Emissions are not considered in this paper.


Author(s):  
Jiang Lu ◽  
Ashwani K. Gupta ◽  
Eugene L. Keating ◽  
Andrew A. Pouring

Abstract Numerical simulation of flow, combustion phenomena and pollutants emission characteristics have been obtained on an homogeneous-charged internal combustion engine having conventional flat piston and five other bowl-in-piston geometries. The code employed here uses the time marching procedure and solves the governing partial differential equations of multi-component chemically reactive flow by finite difference method. The transient solution is marched out in a sequence of time steps. The results show that the piston geometry affects the local flame properties which subsequently influences the pollutants emission level. The numerical results provide a cost effective means of developing advanced internal combustion engine chamber geometry design that provides high efficiency and low pollution. It is expected that increased computational tools will be used in the future for enhancing our understanding of the detailed combustion process in internal combustion engines and all other energy conversion systems. Such detailed information is critical for the development of advanced methods for energy conservation and environmental pollution control.


Author(s):  
Ashwani K. Gupta ◽  
Lu Jiang ◽  
Eugene L. Keating

Abstract Numerical simulation of flow, combustion phenomena and pollutants emission characteristics have been obtained on an internal combustion engine having conventional flat piston and advanced piston geometries. The code employed the time marching procedure that solves the governing partial differential equations of multi-component chemically reactive fluid flow by finite difference method. The transient solution is marched out in a sequence of time steps. The results show that both the piston geometry and inlet flow conditions affects the local flame properties which subsequently alters the pollutants emission levels. The numerical results provide a cost effective means of developing advanced internal combustion engine chamber geometry design that provides high efficiency and low pollution levels. It is expected that increased computational tools will be used in the future for enhancing our understanding of the detailed combustion process in internal combustion engines and all other energy conversion systems. Such detailed information is critical for energy conservation and environmental pollution control.


Author(s):  
L. Andreassi ◽  
A. L. Facci ◽  
S. Ubertini

As a consequence of the endless price growing of oil, and oil derivate fuels, automotive industry is experiencing a concerning decreasing in sales. Accordingly, in order to meet customer needs, there is every day a greater interest in solutions for increasing engine efficiency. On the other hand the growing attention to environmental problems leads to increasingly restrictive regulations, such as European EURO 4 and EURO 5. Direct injection of gaseous fuel has emerged to be a high potential strategy to tackle both environmental and fuel economy requirements. However since the electronic gaseous injection technology is rather new for automotive applications, limited experience exists on the optimum configuration of the injection system and the combustion chamber. To facilitate the development of these applications computer models are being developed to simulate gaseous injection, air entrainment and the ensuing combustion. This paper introduces a new method for modelling the injection process of gaseous fuels in multi-dimensional simulations. The proposed model allows holding down grid requirements, thus making it compatible with the three-dimensional simulation of an internal combustion engine. The model is validated and calibrated by comparing numerical results with available experimental data. To highlight the potential applications, some numerical results of the three-dimensional combustion process in a gas engine are presented.


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