Nikolai Ardey - Academia.edu (original) (raw)

Papers by Nikolai Ardey

MTZ worldwide, Apr 2, 2014

Mtz - Motortechnische Zeitschrift, Jun 18, 2014

MTZ worldwide, Jun 18, 2014

Springer eBooks, 1999

The propagation of gaseous explosions is governed by the interaction of chemical kinetics with th... more The propagation of gaseous explosions is governed by the interaction of chemical kinetics with the molecular and turbulent heat and mass transport. Combustion processes like deflagration and detonation depend on the different valence of physical effects under certain conditions. Geometry and the expansion flow of the flame itself affect the turbulence and therefore the transport of fuel into the reaction zone. The present paper discusses the different hydrogen combustion processes and reports on the experimental investigations of transport phenomena during flame propagation with highly blocking obstacles. Several facilities have been operated with sophisticated optical measurement techniques like high speed schlieren videographie, laser induced predissociation fluorescence and laser doppler velocimetry to obtain detailed information about the combustion process. It will be shown that the turbulent quenching of flames leads to an amount of free radicals resulting in sensitive clouds of those radicals with corresponding high chemical reaction rates, which has a strong influence on the efficiency of the combustion processes.

Heat Transfer 1998, Proceedings of 11th IHTC, Vol. 7 August 23-28, 1998, Kyongju. Korea EFFECT OF... more Heat Transfer 1998, Proceedings of 11th IHTC, Vol. 7 August 23-28, 1998, Kyongju. Korea EFFECT OF TURBULENT TRANSPORT AND MIXING ON FLAME ACCELERATION THROUGH HIGHLY BLOCKING OBSTACLES Martin Jordan, Nikolai Ardey, Franz Mayinger Lehrstuhl A filr ...

Transactions of the American Nuclear Society, Dec 31, 1995

Because of hydrogen release during a hypothetical severe accident in a light water reactor, an in... more Because of hydrogen release during a hypothetical severe accident in a light water reactor, an intense investigation of premixed hydrogen-air combustion and connected safety aspects is being conducted. Hydrogen combustion in the course of a gradual hydrogen release normally starts out from slow deflagrations, which, however, can be accelerated to very high flame speeds by flame-obstacle interaction yielding a complex superimposition of chemical kinetics and turbulent heat and mass transfer. Numerical models for the turbulent burning rate rely mainly on the assumption of continuous wrinkled or corrugated flame fronts, which are stretched or quenched, respectively, by flow strain and small-scale fluctuations. Considerable deviations in calculated burning rates point at physical mechanisms that are not yet satisfactorily understood.

Mtz - Motortechnische Zeitschrift, Dec 1, 2000

Mtz - Motortechnische Zeitschrift, Aug 29, 2015

BMW verbindet die fahrdynamischen Vorteile eines leistungsstarken elek trischen Antriebs mit der ... more BMW verbindet die fahrdynamischen Vorteile eines leistungsstarken elek trischen Antriebs mit der Alltagstauglichkeit eines Verbrennungsmotors im Konzeptfahrzeug Power-E-Drive. Die Betriebsstrategie setzt den Drei zylinder abhängig von der Geschwindigkeit, der Last und des Ladezustands der Batterie ein. © BMW 10I2015 76. Jahrgang BILD 7 Das Beschleunigungsvermögen im Vergleich zu einem Achtzylinder-Turbomotor (© BMW)

MTZ worldwide, Sep 2, 2015

BMW combines the vehicle dynamics of a high-performance electric drive with the road capability o... more BMW combines the vehicle dynamics of a high-performance electric drive with the road capability of an internal combustion engine in its Power E Drive concept vehicle. Depending on speed, load and the battery's state of charge, the operating strategy brings the three-cylinder engine into operation.

40. Internationales Wiener Motorensymposium 15.-17. Mai 2019, 2019

Mit dem neuen 3.0l V6-TDI Gen.3 mit EAV lanciert Audi den Nachfolger des erfolgreichen 3.0l V6-TD... more Mit dem neuen 3.0l V6-TDI Gen.3 mit EAV lanciert Audi den Nachfolger des erfolgreichen 3.0l V6-TDI Biturbo. Der Motor hat eine Leistung von 257 kW und ein maximales Drehmoment von 700 Nm. Die Basis für dieses Aggregat liefert die bereits seit 2017 in Serie befindliche 170/210 kW Variante der Gen.3 Motorenfamilie. Die Kombination aus einstufiger Abgasturboaufladung mit elektrisch angetriebenem Verdichter (EAV) und 48 V Mild-Hybrid-System erlaubt eine noch dynamischere Kraftentfaltung über den gesamten Drehzahlbereich. Die Erfüllung der neuen Zulassungsbedingungen nach WLTP und RDE mit der Emissionsnorm EU6d-Temp sind neben einer hohen Effizienz und herausragendem Anfahrverhalten die Ergebnisse der Weiterentwicklung dieser V6-TDI Motorengeneration. Die Weiterentwicklung des Kühlund Ölkreislaufs, Maßnahmen im Kurbeltrieb, bis zu 2.500 bar Einspritzdruck und Optimierungen des Brennverfahrens tragen wesentlich zur Leistungsund Effizienzsteigerung bei. Ein kombiniertes Niederdruck(ND) und...

Transactions of the American Nuclear Society, 1995

Revista De Administracao Publica, Nov 30, 2012

Este trabalho resume os resultados da primeira parte de um estudo maior sobre o crescimento e des... more Este trabalho resume os resultados da primeira parte de um estudo maior sobre o crescimento e desenvolvimento de elites profissionais no serviço público. Tal estudo espera apresentar um quadro mais realista da natureza do emprego no serviço público brasileiro. Em particular, este ensaio fo-__ caliza os profissionais ou técnicos, estes misteriosos grupos anônimos de pessoas que são às vezes, considerados responsáveis pelos rápidos ganhos industriais da última década e, às vezes, criticados devido às distorções no quadro da distribuição de renda ou, ainda. supostamente. por marginalizar a classe política do Brasil. * Trabalho apresentado no Secap, promovido pela Seplan•Semor, em julto de 1975.

Proceeding of International Heat Transfer Conference 11