Spatial Structure of a Reacting Flow of a Turbulent Swirled Jet during Combustion of a Propane-Air Mixture

Abstract Resolvent analysis is applied to a nonreacting and a reacting swirled jet flow. Time-averaged flows as input for the resolvent analysis and validation for the results of the resolvent analysis are obtained by experiments. We show that in the nonreacting (cold) flow case, the resolvent analysis is capable of predicting the hydrodynamic response to upstream harmonic acoustic forcing if the flow shows low-rank behavior. This is the case for low and moderate acoustic forcing amplitudes. Even for very strong acoustic velocity amplitudes that are of the same order of magnitude as the flow velocity, the resolvent analysis still provides reasonable results. The method also yields very good results for the reacting flow in terms of velocity fluctuation and heat release response to the acoustic forcing. This confirms the idea that the resolvent method could be applied to estimate the flame transfer function (FTF) based on the mean flow and flame.

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Prediction of the Flow Response of a Turbulent Flame to Acoustic Pertubations Based on Mean Flow Resolvent Analysis

Volume 4A: Combustion, Fuels, and Emissions ◽

10.1115/gt2019-90438 ◽

2019 ◽

Author(s):

Thomas Ludwig Kaiser ◽

Lutz Lesshafft ◽

Kilian Oberleithner

Keyword(s):

Turbulent Flame ◽

Low Rank ◽

Reacting Flow ◽

Mean Flow ◽

Cold Flow ◽

Flow Response ◽

Hydrodynamic Response ◽

Order Of Magnitude ◽

Acoustic Forcing ◽

Swirled Jet

Abstract Resolvent analysis is applied to a non-reacting and a reacting swirled jet flow. Time-averaged flows as input for the resolvent analysis and validation for the results of the resolvent analysis are obtained by experiments. We show that in the non-reacting (cold) flow case, the resolvent analysis is capable of predicting the hydrodynamic response to upstream harmonic acoustic forcing if the flow shows low-rank behavior. This is the case for low and moderate acoustic forcing amplitudes. Even for very strong acoustic velocity amplitudes, that are of the same order of magnitude as the flow velocity, the resolvent analysis still provides reasonable results. The method also yields very good results for the reacting flow in terms of velocity fluctuation and heat release response to the acoustic forcing. This confirms the idea that the resolvent method could be applied to estimate the Flame Transfer Function based on the mean flow and flame.

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Observations of the spatial structure of interstellar hydrogen

Symposium - International Astronomical Union ◽

10.1017/s007418090010066x ◽

1967 ◽

Vol 31 ◽

pp. 45-46

Author(s):

Carl Heiles

Keyword(s):

High Resolution ◽

Spatial Structure ◽

Velocity Dispersion ◽

Temperature Variations

High-resolution 21-cm line observations in a region aroundlII= 120°,b11= +15°, have revealed four types of structure in the interstellar hydrogen: a smooth background, large sheets of density 2 atoms cm-3, clouds occurring mostly in groups, and ‘Cloudlets’ of a few solar masses and a few parsecs in size; the velocity dispersion in the Cloudlets is only 1 km/sec. Strong temperature variations in the gas are in evidence.

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Relation between electronic and spatial structure and spin-transition parameters in chain-like Fe(II) compounds

Solid State Ionics ◽

10.1016/s0167-2738(97)00383-4 ◽

1997 ◽

Vol 101-103 (1-2) ◽

pp. 571-577 ◽

Cited By ~ 2

Author(s):

S Erenburg

Keyword(s):

Spatial Structure ◽

Spin Transition ◽

Electronic And Spatial Structure

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Results of Spatial Structure of Atmosphere Radiation in a Spectral Range (1.5–2) µm Research

Light & Engineering ◽

10.33383/2017-061 ◽

2018 ◽

pp. 7-13

Author(s):

Anton M. Mishchenko ◽

Sergei S. Rachkovsky ◽

Vladimir A. Smolin ◽

Igor V . Yakimenko

Keyword(s):

Spatial Structure ◽

Unmanned Aerial Vehicle ◽

Wavelength Range ◽

Spectral Range ◽

Near Ir ◽

Optoelectronic Systems ◽

Aerial Vehicle

Results of experimental studying radiation spatial structure of atmosphere background nonuniformities and of an unmanned aerial vehicle being the detection object are presented. The question on a possibility of its detection using optoelectronic systems against the background of a cloudy field in the near IR wavelength range is also considered.

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