Thermodynamische Grundlagen

Basshuysen, Richard van; Schäfer, Fred

doi:10.1007/978-3-8348-8624-8_5

Cited by 11 publications

(19 citation statements)

References 8 publications

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“…The in-cylinder mass and composition at intake valve closing (IVC) can be determined using the mass flows and a mass balance. The theoretical (isentropic) one-dimensional (1D) stationary flow through a channel is defined as 44…”

Section: Governing Physical Equationsmentioning

confidence: 99%

Development and experimental validation of a real-time capable field programmable gate array–based gas exchange model for negative valve overlap

Gordon

Wouters

Wick

et al. 2018

International Journal of Engine Research

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Homogeneous charge compression ignition has the potential to significantly reduce NO x emissions, while maintaining a high fuel efficiency. Homogeneous charge compression ignition is characterized by compression-induced autoignition of a lean homogeneous air–fuel mixture. Combustion timing is highly dependent on the in-cylinder state including pressure, temperature and trapped mass. To control homogeneous charge compression ignition combustion, it is necessary to have an accurate representation of the gas exchange process. Currently, microprocessor-based engine control units require that the gas exchange process is linearized around a desired operating point to simplify the model for real-time implementation. This reduces the models’ ability to handle disturbances and limits the flexibility of the model. However, using a field programmable gate array, a detailed simulation of the physical gas exchange process can be implemented in real time. This paper outlines the process of converting physical governing equations to an offline zero-dimensional gas exchange model. The process used to convert this model to a field programmable gate array capable model is described. This model is experimentally validated using a single cylinder research engine with electromagnetic valves to record real-time field programmable gate array gas exchange results and comparing to the offline zero-dimensional physical model. The field programmable gate array model is able to accurately calculate the cylinder temperature and cylinder mass at 0.1 °CA intervals during the gas exchange process for a range of negative valve overlaps, boost conditions and engine speeds making the model useful for future real-time control applications.

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Section: Governing Physical Equationsmentioning

confidence: 99%

Development and experimental validation of a real-time capable field programmable gate array–based gas exchange model for negative valve overlap

Gordon

Wouters

Wick

et al. 2018

International Journal of Engine Research

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“…As long as engine knock does not occur, higher engine loads and geometric compression ratios enhance combustion rates due to elevated cylinder pressures. 35…”

Section: Physical Background Of CCVmentioning

confidence: 99%

A physical-based approach for modeling cycle-to-cycle variations within a zero-dimensional/one-dimensional simulation environment

Krost

Hübner

Hasse

2017

International Journal of Engine Research

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In the spark-ignition engine development and optimization process, the cyclic variability of combustion is an essential and current issue. Cycle-to-cycle variations are extensively investigated by means of quasi-dimensional (zero-dimensional/ one-dimensional) simulation modeling. To date, these model approaches have been limited either because they neglected particularly significant physical causes and factors influencing cyclic combustion variations or because of their solely empirical combustion modeling basis. However, in order to ensure the high validity of simulation results, quasidimensional model approaches have to accurately describe the physical background of engine combustion. Therefore, a new cyclic combustion variation model is introduced in this study. This cycle-to-cycle variation model is based on previously developed, highly sophisticated physical turbulence, ignition and combustion models, thus for the first time enabling the physical description of cycle-to-cycle variation. The model integrates the most significant physical causes of combustion variations and the factors which influence them, obtained from a literature study. Hence, the derived cycle-to-cycle variation model can physically react to changes in engine parameters such as the engine speed, load, spark timing, valve lift and timing as well as the air-fuel equivalence ratio l. For validation, the new cycle-to-cycle variation model is compared to a state-of-the-art cycle-to-cycle variation model and analyzed by means of engines with different combustion processes. This new cycle-to-cycle variation model uniquely features the physical background of the underlying combustion model and the integration of more influencing factors than in previous approaches. Another unique feature is its basis on extensive experimental data, gained by changing various engine parameters for homogeneous charge sparkignition engines with different combustion/engine concepts. These include engines with high turbulence generation or a long expansion stroke via crank and valve train.

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“…1) of the engine gas distribution mechanism [3,4]. The valve, being heated during operation up to 1000°С, is the most heat-stressed engine part [5]. It is in permanent contact with its guide and during operation it moves in a reciprocating motion in it.…”

Section: Introductionmentioning

confidence: 99%

“…To ensure a long life of the gas distribution mechanism one, first of all, should pay attention to materials used for making valves and guides as in most cases the cause of failures of this mechanism is incorrect selection of materials for the given purposes. By present, a great variety of materials (steels, nickel and titanium alloys, ceramic materials and other) have been developed the wear-out rate of which is significantly lower than that of valve guides [2,5]. Therefore, when selecting materials, one should, first of all, pay attention to materials for valve guides.…”

Section: Introductionmentioning

confidence: 99%

Analysis of operating conditions of heavy-loaded and heat-stressed friction units of powerful internal combustion engines and development of copper nanocomposite powder materials for them

Shalunov

Shalunov²,

Vladimirova

2019

MATEC Web Conf.

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The article provides analysis of operating conditions for the «valve – valve guide» heavy-loaded and heat-stressed friction unit of the gas distribution mechanism of powerful internal combustion engines and establishes requirements to materials for valve guides. It describes nanoc omposite materials based on copper powder with aluminum, carbon, iron and oxygen additives developed by the authors of the present article. The reactionary mechanical alloying method and powder metallurgy technologies in use made it possible to develop materials having a dispersion-strengthened structure with nano-disperse level sizes of structural components (dispersoids, subgrains). They have a recrystallization temperature of over 950оС, good therm-conductivity, a low linear thermal expansion coefficient and excellent tribotechnical properties. For example, a copper nanocomposite material containing 0.9 wt % aluminum, 0.3 wt % carbon, 0.4 wt % iron and 0.017 wt % oxygen, by its tribotechnical properties, greatly surpasses CuNi2Si (F65 DIN 17666) bronze widely used by many leading engine-making companies for production of valve guides. By their properties, the developed materials meet requirements that have to be imposed on modern and promising materials for valve guides of powerful internal combustion engines.

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Thermodynamische Grundlagen

Cited by 11 publications

References 8 publications

Development and experimental validation of a real-time capable field programmable gate array–based gas exchange model for negative valve overlap

Development and experimental validation of a real-time capable field programmable gate array–based gas exchange model for negative valve overlap

A physical-based approach for modeling cycle-to-cycle variations within a zero-dimensional/one-dimensional simulation environment

Analysis of operating conditions of heavy-loaded and heat-stressed friction units of powerful internal combustion engines and development of copper nanocomposite powder materials for them

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