N. Peters

RWTH Aachen University

363Publications

56H-index

12.5kCitations

Publications 363

Newest

#1Alexander Rubbert (RWTH Aachen University)H-Index: 1

#2Fabian Hennig (RWTH Aachen University)H-Index: 3

Last.N. Peters (RWTH Aachen University)H-Index: 56

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A turbulent flow in a wavy channel was investigated by tomographic particle-image velocimetry measurements and direct numerical simulations. To analyze the turbulent structures and their scaling behavior in a flow undergoing favorable and adverse pressure gradients, the streamline segmentation method proposed by Wang (J Fluid Mech 648:183–203, 2010) was employed. This method yields joint statistical information about velocity fluctuations and length scale distributions of non-overlapping structu...

Propagation speed and stability of spherically expanding hydrogen/air flames: Experimental study and asymptotics

#1Joachim Beeckmann (RWTH Aachen University)H-Index: 10

#2Raik Hesse (RWTH Aachen University)H-Index: 1

Last.Moshe Matalon (UIUC: University of Illinois at Urbana–Champaign)H-Index: 27

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Abstract Here, outwardly propagating spherical hydrogen/air flames are examined theoretically and experimentally with respect to flame propagation speed and the onset of instabilities which develop due to thermal expansion and non-equal diffusivities. Instabilities increase the surface area of the spherical flame, and hence the flame propagation speed. The theory applied here accounts for both hydrodynamic and diffusive-thermal effects, incorporating temperature dependent transport coefficients....

#1K. Seshadri (UCSD: University of California, San Diego)H-Index: 28

#2N. Peters (RWTH Aachen University)H-Index: 56

Last.Guenter Paczko (RWTH Aachen University)H-Index: 2

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A skeletal chemical-kinetic mechanism for n-heptane cool flames is simplified to the maximum extent possible by introduction of steady-state approximations for intermediaries, following procedures employed previously in addressing two-stage ignition. A pair of ordinary differential equations in mixture-fraction space is thereby obtained, describing the quasi-steady structures of the temperature and heptylketohydroperoxide fields. Application of activation-energy asymptotics for the partial-burni...

#1N. Peters (RWTH Aachen University)H-Index: 56

#2Jonas Boschung (RWTH Aachen University)H-Index: 4

Last.Heinz Pitsch (RWTH Aachen University)H-Index: 50

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The two-point theory of homogeneous isotropic turbulence is extended to source terms appearing in the equations for higher-order structure functions. For this, transport equations for these source terms are derived. We focus on the trace of the resulting equations, which is of particular interest because it is invariant and therefore independent of the coordinate system. In the trace of the even-order source term equation, we discover the higher-order moments of the dissipation distribution, and...

#1Jonas Boschung (RWTH Aachen University)H-Index: 4

#2Fabian Hennig (RWTH Aachen University)H-Index: 3

Last.N. Peters (RWTH Aachen University)H-Index: 56

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#1Luke Bates (University of Leeds)H-Index: 3

#2Derek Bradley (University of Leeds)H-Index: 39

Last.N. Peters (RWTH Aachen University)H-Index: 56

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Abstract Many direct numerical simulations of spherical hot spot auto-ignitions, with different fuels, have identified different auto-ignitive regimes. These range from benign auto-ignition, with pressure waves of small amplitude, to super-knock with the generation of damaging over-pressures. Results of such simulations are generalised diagrammatically, by plotting boundary values of ξ , the ratio of acoustic to auto-ignition velocity, against ɛ. This latter parameter is the residence time of th...

JSPS Supported Symposium on Interscale Transfers and Flow Topology in Equilibrium and Non-equilibrium Turbulence (Sheffield, UK, September 2014)

#1Christopher J. Keylock (University of Sheffield)H-Index: 19

#2Shigeo Kida (Dodai: Doshisha University)H-Index: 4

Last.N. Peters (RWTH Aachen University)H-Index: 56

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#1Michael Gauding (Freiberg University of Mining and Technology)H-Index: 7

#2Achim Wick (RWTH Aachen University)H-Index: 2

Last.C. Hasse (Freiberg University of Mining and Technology)H-Index: 23

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The energy transfer between different scales of a passive scalar advected by homogeneous isotropic turbulence is studied by an exact generalized transport equation for the second moment of the scalar increment. This equation can be interpreted as a scale-by-scale energy budget equation, as it relates at a certain scale r terms representing the production, turbulent transport, diffusive transport and dissipation of scalar energy. These effects are analyzed by means of direct numerical simulation ...

#1Fabian Hennig (RWTH Aachen University)H-Index: 3

#2Jonas Boschung (RWTH Aachen University)H-Index: 4

Last.N. Peters (RWTH Aachen University)H-Index: 56

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In this study we investigate the statistical properties of so called streamline segments in a turbulent channel flow with one plane and one wavy wall. We give a short overview of the concept of streamline segments and recent results in description and modeling in this field. We find that streamline segments in the vicinity of the wavy wall are significantly smaller on average than in the core region. However, normalizing the length distribution with the mean segment length leads to an almost per...

#1Michael GaudingH-Index: 7

#2Jens Henrik GoebbertH-Index: 4

Last.C. HasseH-Index: 23

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