Wyniki wyszukiwania - Biblioteka Nauki

1

Diagnostics of internal combustion diesel engines operated in construction and mining

100%

Magdziak-Tokłowicz M. , Miksiewicz K. , Reksa M. , Magdziak D.

Journal of KONES

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2015

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tom Vol. 22, No. 4

191--199

EN

Mining machinery and equipment belong to the group of special machines working in extreme conditions. Mining machines are used in difficult conditions such as limited supplies of fresh air, heat from the rock, in places with high humidity and heavy dust. In other specifics related to the extraction process is brine, harmful compounds such as sulphur dioxide, or rock debris raining down. The machines are operated in continuous mode, the clock. Working in mining conditions machines are exposed to frequent breakdowns and malfunctions. Identifying of failure diesel engines can be cumbersome in these conditions and time-consuming, leading to longer downtime, thereby reducing operating efficiency and increased cost. Therefore, in the paper was a review and analysis methods for the diagnosis of internal combustion diesel engines used in machines built and used to power machines in underground mining. On the basis of diagnostic testing was performed analysis of cases occurring malfunctions and failures.

2

The Laser Doppler Vibrometry in mechatronics diagnostics

100%

Sitnik L. , Pentoś K. , Magdziak-Tokłowicz M. , Wrobel R.

Archives of Civil and Mechanical Engineering

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2015

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tom Vol. 15, no. 4

962--970

EN

The article presents the possibility to diagnose a machine – physical object – in particular diesel engine. Studies were organized to demonstrate the possibility to use LDV (Laser Doppler Vibrometry) in the fundamental (diagnostic) studies. The object tested is a common model of modern diesel engine, frequently used in currently available vehicles. This paper describes the results of researches performed based on the displacement and the velocity, which indicates usefulness of each of these variables. In addition, the article presents older type of vibration detection system uses in vehicles (based on accelerometers) and conditioning path of the received vibroacoustic signal to become complete and fully useful diagnostic information.

3

Testing of internal combustion engines of motorcycles with the use of thermal imaging methods

100%

Magdziak-Tokłowicz M. , Skrętowicz M. , Wróbel R. , Sroka Z.

Journal of KONES

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2017

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tom Vol. 24, No. 4

181--186

EN

The internal combustion engine should be rated for the thermal loads that come from different sources. Thermal analysis is important both for design purposes and for evaluating the conditions of its use. Very good results are obtained by a combination of non-invasive measurement techniques, such as research using infrared thermal imaging techniques [3, 11]. The purpose of the study was to determine the engine thermal load by evaluating the average temperature on the outside surface of the engine at many of its points for two selected motorcycle engines with similar displacement capacities. For many reasons, such as ecology, durability, engine strength and thermal performance when heating and cooling are critical. To accomplish this task, a thermographic technique for indirect evaluation has been used, thus creating the possibility of measuring the temperature in a dynamic manner. These are accurate measurements and most importantly do not interfere with the construction of the object under investigation. The engine was tested during operation according to external and load characteristics. As a result of the work, graphs of temperature curves of heating and cooling of the tested engines were compiled. The article presents a methodology for measuring the temperature fields of outer surface engines. The collected material will be used in the future for studying the equable load on the cylinders, and as accurately as possible determine the conditions of movement such as power, revolutions, flow rates, temperatures and pressures.

4

Vehicle vibration in human health

100%

Sitnik L. J. , Magdziak-Tokłowicz M. , Wróbel R. , Kardasz P.

Journal of KONES

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2013

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tom Vol. 20, No. 4

411--418

EN

Fast development of technology over the last decades has contributed to the adverse effects that may affect human health (both physical and mental). Such negative effects may include noise and vibration. These phenomena are accompanied by most of the technological processes. Need for more efficient and productive processes is causing rising trend in intensifying of these phenomena. It is unavoidable to increase efficiency without increasing the operating speed of machinery and equipment. The main goal of this paper is to carry out NVH (noise, vibration and harshness) analysis of engines; compression-ignition engine (diesel) and spark-ignition engine (gasoline) equipped in the same type of vehicle. But purpose is laying on presented methodology, not results of researches (but of course it will be presented too) which often (mainly) is made for failure detections. This paper will also cover influence of the engine mounting on generated acoustic vibrations followed by comparative NVH analysis of states occurring in diesel and gasoline engine. Scope of the work: a) theoretical introduction, b) presentation of vibration measurement (using LDV: Laser Doppler Vibrometry), c) NVH analysis in two types of engines, d) comparison of results, e) conclusions.

5

Comparative analysis of the vibrations of a different kind of engine mounted in the same new motor vehicles

100%

Sitnik L. , Magdziak-Tokłowicz M. , Wróbel R.

Journal of KONES

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2011

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tom Vol. 18, No. 4

443-448

EN

The paper presents the results of tests carried out on two spark-ignition engines: 1.4BZ 90CV CD and 1.4BZ 120CV CD installed in new Fiat Bravo (model 198, version 54A) motor cars. The latter engine model (120CV) was equipped with a supercharging system. The research consisted in comparing engine vibrations measured in specific and representative points. In order to determine the vertical component vibrations, the measurements were performed via a mirror. A PSV-400 laser Doppler vibrometer made by Polytec was used to measure vibration velocities. The vibrometric system directly measures two quantities: displacement and velocity. In the investigated case, vibration velocity is the variable which supplies better diagnostic information. Vibrations were measured for the car standing on its wheels and for the car jacked up to reduce the influence of the car vibration damping systems on the measurement results. The latter are presented in the form of comparative diagrams. Moreover, the fast Fourier transform was used to determine the frequency distribution. Prior to that signal was subjected to conditioning operations using parametric windowing and filtering. Interesting conclusions emerge from the obtained results and on their basis the effect of the drive unit on the behaviour of the car body can be assessed for different engine types and rotational speeds. It is shown that the way in which the engine is mounted affects the vibrations of the car.

6

Impact analysis of air humidity on operating parameters of diesel engine

88%

Haller P. , Jankowski A. , Kolanek C. , Magdziak-Tokłowicz M. , Wróbel R.

Journal of KONES

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2015

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tom Vol. 22, No. 3

37--42

EN

A major problem in the combustion diesel engines is the different distribution of the mixture of air and fuel and also temperatures inside the combustion chamber. It helps the formation of points of the high and low oxygen concentration in the combustion chamber of the engine. In areas with a high concentration of oxygen, the combustion process produces very harmful NOx, and in places with low oxygen concentration, as a result of incomplete fuel combustion particles are created in the form of soot. This not regular distribution of the mixture of air and fuel and temperatures in the combustion chamber affect the limited maximum engine power and efficiency at his every operating cycle. One method for improving the combustion process is feeding into the engine air with high relative humidity. The study was conducted on a chassis dynamometer at the Department of Vehicles Engineering Wroclaw University of Technology. For the purposes of the study determined the external characteristics, including maximum engine power and maximum engine torque at different air relative humidity and quite similar air temperature. Analysis of the results of research shows that high air relative humidity has a positive effect on the work parameters of the diesel engine.

7

Transmission of vibrations from the engine to the car body

88%

Aleksieva V. , Valchanov H. , Magdziak-Tokłowicz M. , Wróbel J. , Włostowski R.

Journal of KONES

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2016

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tom Vol. 23, No. 4

17--23

EN

Vibrations have become an important factor of vehicles. Vibration tests help identify, and then tune the automotive vehicle to improve the structural strength. Due to the increasing development of vehicles and machines and their widespread use. Increased research-using vibrations due to their low or zero interference with the vehicle under test. Vibration testing is often carried out using Laser Doppler Vibrometry (LDV), a device that is used for contactless measurement of vibration on the surface. The laser beam is directed from the device to the surface of interest, and the amplitude and frequency of vibration are extracted from the Doppler shift frequency of the reflected laser beam due to the movement surface. High values of vibration transmitted from the engine, and the way significantly affect the body of the vehicle and the driver. Article presents results of research carried out on vehicles powered by three different engines and rpm. Tests were carried out on an engine dynamometer in the same environmental conditions. Two of engines were with spark ignition, including one with a supercharged engine and compression ignition engine. The measurements were made using the Laser Doppler Vibrometry using Fast Fourier Transform. The spectrum obtained is used for further analysis to determine the acceleration level at various frequencies. Obtained from Fast Fourier Transform readings used for drawing graphs of frequency V acceleration. The results of the study are interesting and promising, as they show a significant difference in the velocity for spark ignition engines and compression-ignition.

8

Entrance research on pressure distribution in combustion chamber of gasoline engine applied in electric generator, fuelled by syngas, for different ignition timing

75%

Janicka A. , Magdziak-Tokłowicz M. , Rodak M. , Trzmiel K. , Włostowski R. , Zawiślak M.

Journal of KONES

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2015

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tom Vol. 22, No. 4

125--131

EN

Synthetic gas (syngas) produced form waste organic matter may be used as a fuel for internal combustion engines. Possibilities of syngas application as an independent IC engine energy carrier are limited. Designed system of energy conversion from waste to electricity is expected to produce gas consists mainly carbon monoxide, methane, hydrogen and carbon dioxide. Based on theoretical study and own research, as the main factors which impact on floating syngas composition the quality of input substance, process temperature and gasifying medium application were identified. The fluctuation of syngas composition contributes important challenge in aspect of energetic efficiency and mechanical durability of generator system. The researches were provided on research test bed, which enables pressure distribution measurement in the combustion chamber (for various mixture of synthetic gases) and correction of ignition timing. The results of the researches indicate that proper correction of the ignition advance allows syngas mixtures combustion in wide range of their composition.

9

The methodology of grade of gasification reactor effectivity

75%

Jagiełło A. , Magdziak-Tokłowicz M. , Górniak A. , Trzmiel K. , Włostowski R. , Wróbel R.

Journal of KONES

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2015

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tom Vol. 22, No. 4

109--116

EN

Ecology problems are addressed in all areas of engineering. Gasification is widely used methodology, which allows to power vehicles and fuel generators via alternative fuel. The more it seems important to address the issues of gasification in the group of scientists dealing with machines. In article authors present results of methodology in effectivity of gasification graduation. The base of experiment is the complimentary reactor, which was made for gasification of different materials. Gases that are achieved on the output of the system are used to supply combustion engines. In article, expect mentioned methodology, authors present reactor build and measurement (including complimentary software) system, mounted on system. The new energy supplies are still discovered. At the same time, researchers on good know substances are in progress. In article, authors are presented one of the methods of gasification reactor effectivity. Authors’ reactor has a burning chamber, and outlet circuit. Presented methodology was relayed on E-E system with software part. System is contained a few thermocouples with multiplexing ADC card for acquisition of data. All parts are presented in an article. An article is a result of progressing grant in DEMONSTRATOR+ program (no. WND-DEM-1-527/001).