Mihai Aurel CRIŞAN


31-77 CONTRIBUȚII LA CERCETAREA APLICATIVĂ A ASPECTELOR CINEMATIC-FENOMENOLOGICE ALE SEGMENȚILOR UNUI MOTOR CU APRINDERE PRIN COMPRIMARE UTILIZAT ÎN AGRICULTURĂ ȘI INDUSTRIA AUTO

Contributions to applied research OF kinematic-phenomenological aspects of PISTON-rings for compression ignited engine used in agriculture and automotive industry

 

The present scientific paper synthesizes an applied work on the engineering task of piston-ring displacement modelling and simulation in the case of an internal combustion engine for agricultural application. Piston-rings configuration and displacement, as well as their particular role in the whole assembly, materials, dimensions and lubrication process, in various working cases, are quite significant in influencing the engine’s performance and economy (oil consumption and pollution). In this paper are highlighted the piston-ring displacement modelling and their critical efforts analyse for an agricultural engine, defined on the bases Lombardini tractor engine (510 ccm). The opportunity and importance of modelling the piston-rings movement at different levels and cases in the operational cycle lay on the possibility of highlighting their stresses and predict work expectancy.

 

Keywords: analyse, engine, rings, simulation, tractor

Cuvinte cheie: analiză, motor, segmenți, simulare, tractor

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31-63 CONTRIBUȚII LA CERCETAREA EXPERIMENTALĂ A VISCOZITĂȚII ȘI DENSITĂȚII LUBRIFIANTULUI UNUI MOTOR CU APRINDERE PRIN COMPRIMARE DE LA TRACTOR ALIMENTAT CU BIOCOMBUSTIBIL

Contributions to experimental research OF lubricant viscosity and density from tractor compression ignition engine supplied with biofuel

 

The present research paper shows some of the results achieved during practical tests on the compression ignited engine of a mini-tractor for agricultural use.

The developed tests were conducted in order to point out the influence of working time, type of fuel and temperature regime on the main physical properties of the lubricant. There were monitored the viscosity and density of lubricant and of few blends between the lubricant and the supplied fuels. In the research work are also highlighted the main engine components and the test-bed infrastructure in order to facilitate further improvement and development of the procedure.

The necessity and high importance of testing the lubricant main properties, as viscosity and density, at different temperature levels and in various cases of fuel supply methods and substances in the compression ignited engine is based on the ubiquity of biofuel implementation in modern commercial fuels.

 

Keywords: cylinder, friction, lubricant, tribology, viscosity

Cuvinte cheie: cilindru, frecare, lubrifiant, tribologie, viscozitate

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30-50 CERCETĂRI PRIVIND MODELAREA SISTEMULUI DE UNGERE LA MOTORUL LOMBARDINI 3LD51

RESEARCHES CONCERNING MODELING OF LUBRICATION
SYSTEM IN 3LD510 LOMBARDINI ENGINE
Lubricating system from any engine plays an significant role in
generating all of its dynamic performances. Fuel economy and energetic
performances from all compression ignition engines correlate with the working
degree of its lubricating system. The present work studies the mathematical
models of important phenomena from lubricating process. Compression ignition
engine lubrication process has a considerable part in influencing all sequences
of the working cycle and the components life duration. Some phenomena that
influence the lubricating process have a significant role in the engine durability
and consequently on pollution level. Environmental problem and engine’s
working time are significant problems for everyone in the present days. Human
life style has a specific relation with the ambient and modern engines. The
present article studies and outlines the influence of fuel type and engine’s
speed upon the compression ignition engine power losses, due to the
lubrication process through simulation and modeling. It is obvious that there are
very important factors which highly influence the quality of the lubricating
process and thus of the engine’s losses. In this study are presented the
variations and graphs of some important factors that are influenced by the
lubricating process in various situations, determined by complex analyze of
available data with a virtual model in simulation program.
Keywords: engine component, compression, fuel economy, lubrication, wear
Cuvinte cheie: componente motor, compresie, economie, lubrifiere, uzură

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26-49 EVALUAREA ANALIZELOR DE LABORATOR ALE LUBRIFIANŢILOR ŞI PROCESELOR DE UNGERE ÎN MECANISMELE MOTORULUI CU APRINDERE PRIN COMPRIMARE ÎN FUNCŢIE DE CONŢINUTUL DE BIODIESEL ÎN COMBUSTIBIL

EVALUATION OF LABORATORY ANALYSIS OF LUBRICANTS AND LUBRICATING PROCESSES IN COMPRESSION IGNITED ENGINES’ MECHANISMS DEPENDING ON BIODIESEL CONTENT IN FUEL
Biodiesel use as fuel is a reality today. It is used in compression ignited engines throughout the entire planet. It may come alone or in mixtures with other fuels, either conventional ones or alternative solutions. Biodiesel itself is a bio-alternative solution for fossil fuels. In the present days the content of biodiesel in commercial fuels throughout the country does not exceed 10 %, but in the coming years it will increase toward 20 % and more. There have to be an extensive knowledge and scientific approach related to the effects that biodiesel has upon engine’s lubricants and lubrication processes. In this paper are presented some studies that were developed toward this specific objective and the significant conclusions which were made possible after the research. There are important influences of the biodiesel use as fuel even in the quality of engine lubrication process.
Keywords: biodiesel, lubrication, compression-ignition engines, engine lubricant, physic-chemical characteristics

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