Temat: errors - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Influence of TDC determination methods on mean indicated pressure errors in marine diesel engines
Autorzy:: Pawletko, R.
Polanowski, S.
Powiązania:: https://bibliotekanauki.pl/articles/242218.pdf
Data publikacji:: 2011
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: TDC determination
coordinate of zero value of second derivative
TDC position influence on MIP errors
Opis:: The paper presents the results of comparative analysis of influence of different methods of TDC determination for the calculation errors of mean indicated pressure (MP). Lemag method based on zero point of first order derivative, used in PREMET pressure analyzers, was compared to the method based on a polynomial model of the compression process. Comparisons were made on the operating measurement data obtained on the low speed marine engine RTA96C which forms the main propulsion of the vessel and the medium speed engine MAN L28/32A. Measurements were made with onboard combustion PREMET analyzer. It was found that the method based on zero point of first order derivative can give the deviations of position of TDC in excess of 2°CA which is caused by disturbances associated with the measurement of pressure and interference associated with the generation of the angular axis. These errors are related to the accuracy of the methods of determining of the first derivative and the availability of a sufficient range of pure compression after TDC. The best results of determining the TDC position was obtained from the original method based on a polynomial model of the compression process. It should be emphasized that the proposed method enables individual adjustment of TDC for each cylinder and can be used even when the combustion begins before TDC. The conducted research proved the existence of significant influence of indicator graph TDC location on the mean indicated pressure calculation errors.
Źródło:: Journal of KONES; 2011, 18, 2; 355-363
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Evaluation accuracy of combustion chamber tightness in piston engines, on the basis of a developed indicator diagram
Autorzy:: Rosłanowski, J.
Charchalis, A.
Powiązania:: https://bibliotekanauki.pl/articles/246594.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: leakage of combustion chamber
errors of developed indicator diagrams
characteristic points of developed indicator diagrams
Opis:: The following article describes the effect of combustion chamber leakage of piston engine on the quality of its performance. To make a diagnosis of combustion chamber tightness, only such parameters were selected which are characterized by high information value and are closely connected with its defined structure. For this reason such connections are unmistakable, which results in making the right diagnosis of combustion chamber tightness of piston engines. Special attention was paid to the fact, what consequences, combustion chamber leakage, can cause to the piston engine performance. The most dangerous for the engine efficiency is the leakage of combustion chamber. The leakage of combustion chamber brings about the change of such engine parameters as pressure of suction, pressure of final compression and burning and the change of exhaust gases composition, which effect on the engine power and on fuel consumption. Condition of piston rings and their influence on gas pressure in combustion chamber has also been characterized. Pressure of gases taking place in engine cylinder and their connection with leakage of combustion chamber have also been described. The article also exposes random character of combustion pressure in engine cylinder. Besides, the errors of indicator diagrams together with mapping error position GMP have been mentioned too. Reliability of diagnostic parameters of technical condition of combustion piston engines obtained on the basis of developed indicator diagrams has been defined. Such diagram must be made on the basis of measurements and statistic analysis of pressure parameters in correctly adjusted engines, being in perfect technical condition, and not on the basis of measurements obtained in the engine test bench of a new engine. Bad technical condition, especially leaks in its cylinders causes power differences in engine arrangements, which endangers its safe exploitation.
Źródło:: Journal of KONES; 2013, 20, 3; 339-345
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Diagnostic symptoms of piston combustion engines of ship main propulsion received from its developed indicator diagrams
Autorzy:: Rosłanowski, J.
Charchalis, A.
Powiązania:: https://bibliotekanauki.pl/articles/244511.pdf
Data publikacji:: 2013
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: leakage of combustion chamber
errors of developed indicator diagrams
characteristic points of developed indicator diagrams
Opis:: The following article describes parameters of developed indicator diagrams concerning piston combustion engine of ship main propulsion, which can be used to assess its technical condition. To make a diagnosis of the engine combustion only such parameters should be selected which are characterized by high information value, being closely connected with its one defined structure. This is the cause why such connections are of unmistakable character, which allows to make the right diagnosis of technical condition of piston engine. Special attention was also paid to the consequences of diagnostic symptoms qualification from developed indicator diagrams of ship propulsion engine working in different conditions. Deflection of average indicated pressure caused by inappropriate engine performance could be caused by: 1) faulty adjustment of injection pump; 2) leaky combustion chamber, 3) bad technical condition of injection apparatus and the loading air system. Wrong technical condition of the engine caused by a leaky combustion chamber brings about a decrease of its performance. Untight combustion chamber causes the change of such parameters as, suction pressure, pressure of final compression and burning, as well as, the change of exhaust gases composition, which influences the power of the engine and fuel consumption. It has been mentioned what gas pressures of working process in engine cylinders are connected with an untight combustion chamber. Random character of burning pressure course in engine cylinder has also been paid attention to. Reliability of diagnostic parameters of piston engine technical condition received based on developed indicator diagrams have been determined. Diagnostic symptoms have been defined, basing on measurements and statistical analysis of pressure values in the cylinders of properly adjusted engines being in excellent technical condition and not based on measurements received in the engine test bed of a new engine.
Źródło:: Journal of KONES; 2013, 20, 2; 355-362
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: The errors of the numerical calculations of dynamic characteristics of cantilever beam mounted on the plate
Autorzy:: Van Doan, D.
Murawski, L.
Powiązania:: https://bibliotekanauki.pl/articles/241883.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: T-Beam
vibration
ship structure
modal analysis
FEM errors
wibracja
struktura statku
analiza modalna
błędy MES
Opis:: The safety, comfort of the crews, stability, economics of the equipment when ship operating is the leading requirement in the field of designing and manufacturing marine structure and machinery. As a result, all parts of the ships must be tested and inspected to meet the basic safety requirements of the shipping association. The design, manufacture, testing in the maritime field in general and shipbuilding sector in particular are expensive, time consuming: such as aerodynamic experiments of the engine, collision test, ship manoeuvring, vibration test and balance of deck beams, hull beams, hatch covers, shafts ...thus experimental works are sometimes impossible. Along with the development of computer science, many numerical models and software programs have been developed to solve these difficult problems. There are many numerical modelling methods, starting with the finite difference method, the boundary element method, the finite element method, the no mesh method, the weight residue or the energy method. The Work will be limited to the analysis of the most popular numerical modelling method - finite element method using Patran and Nastran software. In the first step of our research, T-beam was analysed as a part of ship hull structure (thin-walled structure). The article goes into the analysis of the accuracy of selected numerical models for the natural vibration frequency of the T-beams mounted on the plate. After modelling, calculating the natural frequency of the T-beam using the Patran - Nastran software, the results were compared with the theoretical values. From that, we evaluate the dispersion and error of different numerical models and select the optimal numerical model. Optimal model will be used for modelling full ship hull with superstructure.
Źródło:: Journal of KONES; 2018, 25, 1; 433-440
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: The magnetic field curvature correction algorithm dedicated for helmet mounted cueing systems
Autorzy:: Adamski, M.
Szelmanowski, A.
Powiązania:: https://bibliotekanauki.pl/articles/949523.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport
avionics
helmet-mounted cueing systems
errors of the angular positioning
magnetic field measurement
flat coil profile modelling
Opis:: The article presents the new built in Poland helmet mounted cueing system NSC-1 Orion with a magnetic method, dedicated to the multi-purpose helicopters W-3PL Gluszec. This system uses the magnetic field generated by the system of three mutually orthogonal electric coils. The principle of operation of this system is described and the method of determining the angular position of the pilot's helmet relative to the helicopter's cabin using the reference magnetic field and the directional cosines matrix are discussed. Electrical flat coils, constructed in the Polish Air Force Institute of Technology (AFIT), generating a magnetic field with curved symmetry axis characteristics, causing errors in determining the angular position of the pilot's helmet are shown. As a way to minimize these errors, an original proprietary algorithm for correcting the negative impact of the magnetic field curvature generated by the on-board system has been presented. Mathematical relations describing the presented correction process as well as selected results of simulation and experimental investigations in the area of inaccuracy of the "before" and "after" systems of applying the developed algorithm were given. Inaccuracies determined from computer simulations of the developed mathematical relations were compared with experimental data from magnetic field measurements using the integrated three-axis sensor ADIS-16405, used in the laboratory of the AFIT Avionics Division for helmet control of the angular position of the moving observation and sighting head and reflector-search light.
Źródło:: Journal of KONES; 2018, 25, 2; 15-30
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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