Wyniki wyszukiwania - Biblioteka Nauki

1

Badania wpływu liczby cetanowej oleju napędowego na właściwości rozruchowe silników o ZS

100%

Koliński K. , Pszczółkowski J.

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2000

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tom Vol. 49, nr 7

126-135

PL

Przedstawiono wyniki badań wpływu liczby cetanowej, składu grupowego i frakcyjnego olejów napędowych na właściwości rozruchowe silników o zapłonie samoczynnym. Badania rozruchowe przeprowadzono w komorze niskich temperatur na siedmiu różnych silnikach o zapłonie samoczynnym.

EN

The test results of influence the diesel fuels cetane number, group and frakcion compound on the diesel with autoignition start-up basic parameters are presented. The start-up tests were conducted in low temperature chamber with using the seven engines with autoignition.

2

Design of the rapid compression machines for combustion researches in spark ignition engines

100%

Leżański T. , Sęczyk J. , Wolański P.

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tom Vol. 19, No. 4

379-391

EN

The rapid compression machines (RCM) are extensive applied to combustion process researches and mixture process preparation research in the internal combustion engines (ICE). The principal advantage of these arrangements is easy optical access to the inside space of combustion chamber. This enables to observe the course of ignition process and the flame propagation process. There are some RCM designs, which they differ, first of all, the modelling method of piston movement into cylinder. The most known designs use the pneumatic and hydraulic drives. Their concern is that they enable the modelling compression stroke only but combustion is performed in constant volume combustion chamber. It was not relevant for the research of the new combustion system elaborated at Aircraft Engine Department of Warsaw University of Technology (AED). The RCM elaborated at AED has unique form it includes the crank mechanism, speedy operating electromagnetic clutch and flywheel. The applying of this design enables modelling the compression stroke and working stroke (two-stroke from engine cycle). It enables assessment of the system with semi-open combustion chamber what it will be impossible using other RCM designs. The different designs RCM used for combustion research at the research and development centres, on worldwide will be compared with the design of RCM developed at AED. The most known designs of the different RCM were described and the research result examples were given in this paper. The advantages and disadvantages of the different designs were discussed too in this paper.

3

Research of flame propagation in combustion system with semi-open combustion chamber for gasoline SI engines

100%

Leżański T. , Sęczyk J. , Wolański P.

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tom Vol. 18, No. 2

251-260

EN

Some results of visualization researches of combustion system with divided, semi - open combustion chamber for SI engines, using rapid compression machine (RPM) and experimental visualization engine (EVE) are presented in his paper. Short description of combustion system operation, description of test stands and research equipment can be found in the paper. The tests were performed at stoichiometric ratio natural gas-air and propane-air mixtures. A few the most characteristic of results are shown; to explain how should be operate the combustion system, to yield the better performance. They are compared the research results (photographs of combustion sequence, diagrams of in-cylinder pressure histories) during visualization testing with using RCM and EVE. During RCM testing we obtained the combustion photographs in the plain pass in cylinder axis but during ECE testing at the plain perpendicular to the cylinder axis. All researches shown that the best performance are yielded when a spark advance angle (ignition timing) is such selected that stream outflow prechamber to main combustion chamber starts when the piston is at TDC and it has adequate energy to travel a main combustion chamber with higher velocity than burning velocity in quiescent chamber. Then the shortest time of combustion, the highest peak pressure in the cycle and bigger useful working are yielded. The impact of spark advance angle on flame propagation process into combustion chamber in extreme cases has been analyzed too.

4

Numeryczna symulacja wpływu podziału dawki paliwa na jego rozpylenie w układzie wysokociśnieniowego wtrysku benzyny

63%

Pielecha I. , Maslennikov D. , Czajka J. , Wisłocki K.

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2011

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tom nr 6

PL

Artykuł dotyczy badań wtrysku benzyny w aspekcie wpływu czasu przerwy między kolejnymi dawkami paliwa na ich interakcje. Przeprowadzono badania zasięgu strugi paliwa z wtryskiem dwuczęściowym w różnych odstępach czasu, takich aby wtrysk kolejnej porcji paliwa swoim zasięgiem obejmował porcję pierwszą. W tym celu określono zasięg oraz powierzchnię zajmowaną przez strugi paliwa. Przeprowadzono analizę koncentracji paliwa w przekrojach strugi: pojedynczej oraz tzw. kumulowanej, wynikającej z wtrysku dodatkowej porcji paliwa. Badania przeprowadzono dla zróżnicowanych wartości: wielkości dawki paliwa, ciśnienia paliwa oraz odstępów czasowych między kolejnymi porcjami paliwa. Wykorzystanie metod optycznych pozwoliło na określenie mechanizmów działających w strudze paliwa podczas wtrysku wieloczęściowego.

EN

The experimental and numerical investigations of a multiple gasoline injection in the aspect of the influence of the injection dwell time on the interactions between the fuel doses have been discussed in the paper. The fuel spray penetration has been analyzed at a two-stage injection of different dwell times ensuring that the injection of the second fuel dose covered the area already occupied by the first one. To this end, the fuel spray penetration and area occupied by the spray were determined. The analysis of the fuel concentration in the fuel spray cross section has been performed (single and cumulative fuel spray the latter resulting from the overlapping injection of an additional fuel portion). The utilization of optical methods in the investigations allowed determining of the mechanisms governing inside the fuel spray during a multiple injection.