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Improving Diesel Engine Reliability Using an Optimal Prognostic Model to Predict Diesel Engine Emissions and Performance Using Pure Diesel and Hydrogenated Vegetable Oil

Žvirblis Tadas, Hunicz Jacek, Matijošius Jonas, Rimkus Alfredas, Kilikevičius Artūras, Gęca Michał

Eksploatacja i Niezawodność

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2023

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Vol. 25, no. 4

art. no. 174358

EN

The reliability of internal combustion engines becomes an important aspect when traditional fuels with biofuels. Therefore, the development of prognostic models becomes very important for evaluating and predicting the replacement of traditional fuels with biofuels in internal combustion engines. The models have been made to model AVL 5402 engine emission, vibration, and sound pressure parameters using a three-stage statistical regression models. The fifteen parameters might be accurately predicted by a single statistic presented here. Both fuel type (diesel fuel and HVO) and engine parameters that can be adjusted were considered, since this analysis followed the symmetry of the methods. The data analysis process included three distinct steps and symmetric statistical regression testing was performed. The algorithm examined the effectiveness of various engine settings. Finally, the optimal fixed engine parameter and the optimal statistic were used to construct an ANCOVA model. The ANCOVA model improved the accuracy of prediction for all fifteen missing parameters.

2

Comparative study of combustion and emissions of diesel engine fuelled with FAME and HVO

Hunicz Jacek, Krzaczek Paweł, Gęca Michał, Rybak Arkadiusz, Mikulski Maciej

Combustion Engines

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2021

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R. 60, nr 1

72--78

EN

This study investigates combustion and emission characteristics of a contemporary single-cylinder compression ignition engine fuelled with diesel, fatty acid methyl esters (FAME) and hydrotreated vegetable oil (HVO). These two drop-in fuels have an increasing share in automotive supply chains, yet have substantially different physical and auto-ignition properties. HVO has a lower viscosity and higher cetane number, and FAME has contrary characteristics. These parameters heavily affect mixture formation and the following combustion process, causing that the engine preoptimized to one fuel option can provide deteriorated performance and excess emissions if another sustainable option is applied. To investigate the scale of this problem, injection pressure sweeps were performed around the stock, low NOx and low PM engine calibration utilizing split fuel injection. The results showed that FAME and HVO prefer lower injection pressures than diesel fuel, with the benefits of simultaneous reduction of all emission indicators compared to DF. Additionally, reduction of injection pressure from 80 MPa to 60 MPa for biodiesels at low engine load resulted in improved brake thermal efficiency by 1 percentage point, due to reduced parasitic losses in the common rail system.

3

Effects of combustion timing on pressure rise rates in a residual effected HCCI engine

Hunicz Jacek, Gęca Michał, Kordos Paweł, Rybak Arkadiusz

Combustion Engines

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2019

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R. 58, nr 3

46--50

EN

Realization of a low temperature combustion concept in homogeneous charge compression ignition (HCCI) engines is a cutting-edge technology that offers clean combustion in parallel with high thermal efficiency. Low combustion temperature prevents from NOx formation whereas homogeneous mixture assures smokeless exhaust. However, achieving the production feasibility by HCCI technology is hampered by high pressure rise rates and the resulting combustion noise at a high load operation. This paper explores combustion timing parameters that are capable of maintaining permissible levels of pressure rise rates under a high load regime. On the basis of experimental data collected at a high load HCCI operation, pressure rise level was correlated with combustion duration. Furthermore, combustion duration has been found to scale with in-cylinder volume, for which 50% of mass fraction burned appeared. The results showed quantitatively limitations of engine load, pointing out on required combustion timings to achieve acceptable combustion harshness depending on engine load.

4

The air flow influence on the drag force of a sports car

Czyż Zbigniew, Karpiński Paweł, Gęca Michał, Diaz Jacobo Ulibarrena

Advances in Science and Technology. Research Journal

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2018

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Vol. 12, no 2

121--127

EN

The paper presents the numerical analysis of the drag force generated on the body of a sports car, based on the CFD method in the Ansys Fluent program. The three-dimensional model of the vehicle was taken from an open CAD database. Based on this, a computational grid was developed, boundary conditions and a turbulence model were defined. As a result of the calculations, the pressure distribution on the individual body parts and the velocity distribution in selected cross sections were obtained. In the next part of the research, the simulation results are used to optimize the shape of the bodywork of different passenger vehicles in order to reduce the generated drag force.

5

HCCI jako alternatywny system spalania w silnikach tłokowych

Gęca Michał, Hunicz Jacek, Kordos Paweł, Niewczas Andrzej

Zeszyty Naukowe WSEI. Seria Transport i Informatyka

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2012

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T. 2, nr 1

17--26

PL

W pracy przedstawiono koncepcję oraz energetyczne i ekonomiczne efekty zastosowania systemu spalania HCCI (ang. homogeneous charge compression ignition) w silniku tłokowym zasilanym benzyną. System spalania HCCI wykorzystuje samozapłon mieszanki jednorodnej, co pozwala na zwiększenie sprawności cieplnej oraz radykalne obniżenie emisji tlenków azotu z cylindra w porównaniu z silnikami o zapłonie iskrowym. Aby umożliwić samozapłon benzyny, przy stopniu sprężania typowym dla silnika o zapłonie iskrowym, do dostarczania ciepła do czynnika roboczego wykorzystano wewnętrzną recyrkulację spalin uzyskaną poprzez ujemne współotwarcie zaworów. Badania eksperymentalne potwierdziły zalety tego nowego systemu spalania. W zakresie małych obciążeń uzyskano około 15% redukcję zużycia paliwa w porównaniu ze spalaniem ładunku jednorodnego przy zapłonie iskrowym oraz zmniejszenie emisji tlenków azotu o 99%.

EN

The paper presents an idea of HCCI (homogeneous charge compression ignition) combustion system. Efficiency improvement and ecological effects of its application were also presented in this study. The HCCI combustion system utilizes homogeneous charge auto-ignition and allows for increase of thermal efficiency and simultaneous reduction of nitrogen oxides emission in comparison to spark ignition engines. In order to achieve gasoline auto-ignition, at compression ratio typical to spark ignition engines, additional heat was introduced to working fluid via application of internal gas re-circulation obtained with the use of the negative valve overlap technique. Experimental results proved advantages of this new combustion concept. In the low load range of engine operation reduction of specific fuel consumption at level of 15% was achieved, while simultaneous drop in terms of nitrogen oxides emission was about 99%.