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Charakterystyka akustyczna turbosprężarek szybkoobrotowych silników ZS

Opaliński A., Willmann M., Mass U.

Silniki Spalinowe

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2005

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R. 44, nr 4

60--64

PL

Zwiększenie mocy i momentu obrotowego nowoczesnych silników o zapłonie samoczynnym przy jednoczesnym obniżeniu emisji związków szkodliwych i zużycia paliwa nie byłoby możliwe bez zastosowania doładowania turbosprężarkowego. Szerokie rozpowszechnienie tego typu silników spowodowało zmianę stosunku użytkownika do hałasu emitowanego przez turbosprężarki. Współcześni kierowcy cenią sobie właściwości trakcyjne doładowanych silników ZS, jednak hałas emitowany przez turbospreżarki przestał być symbolem mocy i nowoczesności, i jest obecnie postrzegany jako czynnik obniżający komfort jazdy. Z tego powodu przy projektowaniu i testowaniu silników turbodoładowanych konieczne jest uwzględnienie nie tylko zagadnień związanych z termodynamiką i niezawodnością, ale także z akustyką. W artykule dokonano systematyki dźwięków emitowanych przez turbosprężarki, opisano ich źródła, drogi transmisji oraz metody zapobiegania.

EN

The continuously increasing performance data of the modern diesel engines as well as the fulfillment of the very restricted emission standards cannot be realized without the aid of the turbocharger. Due to the prevalence of the turbo charged engines the customer's attitude to the emitted noises has been changed. The customer wishes a high power output, but no longer wants to hear it. Thus the consideration of the noise characteristics during the development work is recently as important as the thermodynamic or durability issues. This paper deals with different turbocharger noises, describes its sources, transmission routes and possibilities of noise reduction.

2

Interaction between injection timing, EGR – rate and rate of heat release in the TDI – engine

Willmann M., Opaliński A., Wisłocki K.

Journal of KONES

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2002

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Vol. 9, No. 1-2

275-282

EN

The high-speed diesel engine has been developed intensively in the past few years. Customer-relevant engine performance data such as BMEP, fuel consumption, exhaust and noise emissions have been improved and the advantages in comparison to the gasoline engine (fuel consumption and torque characteristics) has become more significant. To comply with the very low soot and NOx – limits diesel engines operate with high injection pressure, high EGR – rate and very late injection timing. As these low emissions are the result of different Rates of Heat Release (ROHR), it has to be investigated which features of ROHR are relevant to emissions. They provide important information as to the direction that further development work should take. The investigations were made for broad parameter variation at different engine operating points. As one result it can be pointed out that ROHR itself is not sufficient to describe emissions. At some operating points with different A/F ratios the ROHR were the same and emissions were different. However, ROHR in connection with A/F – ratio and other thermodynamic parameters give very good information on NOx and soot emissions which indicates the practical possibilities to reduce these emissions.

3

A practical approach in the thermodynamical analysis of the TDI - process

Willmann M., Vanhaelst R., Opalinski A.

Journal of KONES

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2001

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Vol. 8, No. 1-2

35-44

EN

High speed diesel engines have been developed intensively in the past few years.The customers relevant engine performance data as: bmep, fuel consumption, exhaust and noise emissions have been improved. To reach all objectives in time, all affords of designers and scientists with the aid of a modern development will be necessary. This paper deals with new methods and theories in the thermodynamical analysis of the TOI engine, which need a cylinder indicating pressure, optical measurements and new calculation models. To evaluate the rate of heat-release, which is introduced into the 2-zone-model, the measured cylinder pressure has to be adjusted. With the aid of a new procedure the absolute level of the measured pressure can be determined. In addition to that an improved method for evaluation of the cylinder-mass in the EGR-mode will be presented. The combination of the calculated rate of heat - release and measured values from the test cell like the composition of exhaust gas will be read into a new theory of two zones. The concentration of NO and soot will be calculated in dependence of the crank angle and verified by optical measurements. The goal of this research work is to reduce the exhaust gas emissions through a better understanding of the internal combustion process. With the so obtained results it would be able to modify engine control and design. The report about the use of the new methods and theories during thermodynamic analysis at the TDI-research will be continued.