scholarly journals High-Frequency Asymptotics and One-Dimensional Stability of Zel’dovich–von Neumann–Döring Detonations in the Small-Heat Release and High-Overdrive Limits

2011 ◽  
Vol 203 (3) ◽  
pp. 701-717 ◽  
Author(s):  
Kevin Zumbrun
Keyword(s):  
Heat Release ◽  
Dimensional Stability ◽  
High Frequency ◽  
Von Neumann ◽  
One Dimensional

High-frequency, "quantum" and electromechanical effects in quasi-one-dimensional charge density wave conductors

2013 ◽  
Vol 183 (1) ◽  
pp. 33-54 ◽  
Author(s):  
Vadim Ya. Pokrovskii ◽  
Sergey G. Zybtsev ◽  
Maksim V. Nikitin ◽  
Irina G. Gorlova ◽  
Venera F. Nasretdinova ◽  
...  
Keyword(s):  
Charge Density ◽  
High Frequency ◽  
Charge Density Wave ◽  
Density Wave ◽  
One Dimensional ◽  
Electromechanical Effects

scholarly journals High-order compact LOD methods for solving high-dimensional advection equations

2021 ◽  
Vol 40 (3) ◽  
Author(s):  
Bo Hou ◽  
Yongbin Ge
Keyword(s):  
Truncation Error ◽  
Three Dimensional ◽  
Taylor Series Expansion ◽  
High Order ◽  
High Dimensional ◽  
Analysis Method ◽  
Order Accuracy ◽  
Von Neumann ◽  
One Dimensional ◽  
Von Neumann Analysis

AbstractIn this paper, by using the local one-dimensional (LOD) method, Taylor series expansion and correction for the third derivatives in the truncation error remainder, two high-order compact LOD schemes are established for solving the two- and three- dimensional advection equations, respectively. They have the fourth-order accuracy in both time and space. By the von Neumann analysis method, it shows that the two schemes are unconditionally stable. Besides, the consistency and convergence of them are also proved. Finally, numerical experiments are given to confirm the accuracy and efficiency of the present schemes.

DIAGONALIZATION MODULO NORM IDEALS AND HAUSDORFF DIMENSIONALITY

2000 ◽  
Vol 11 (08) ◽  
pp. 1057-1078
Author(s):  
JINGBO XIA
Keyword(s):  
Hausdorff Measure ◽  
Metric Spaces ◽  
Adjoint Operator ◽  
Trace Class ◽  
Multiplication Operators ◽  
Von Neumann ◽  
Dimensional Hausdorff Measure ◽  
One Dimensional ◽  
Compact Metric Spaces ◽  
The One

Kuroda's version of the Weyl-von Neumann theorem asserts that, given any norm ideal [Formula: see text] not contained in the trace class [Formula: see text], every self-adjoint operator A admits the decomposition A=D+K, where D is a self-adjoint diagonal operator and [Formula: see text]. We extend this theorem to the setting of multiplication operators on compact metric spaces (X, d). We show that if μ is a regular Borel measure on X which has a σ-finite one-dimensional Hausdorff measure, then the family {Mf:f∈ Lip (X)} of multiplication operators on T2(X, μ) can be simultaneously diagonalized modulo any [Formula: see text]. Because the condition [Formula: see text] in general cannot be dropped (Kato-Rosenblum theorem), this establishes a special relation between [Formula: see text] and the one-dimensional Hausdorff measure. The main result of the paper is that such a relation breaks down in Hausdorff dimensions p>1.

A Selective Fast Fourier Filtering Approach Applied to High Frequency Thermoacoustic Instability Analysis

2017 ◽  
Author(s):  
Felix Grimm ◽  
Jean-Michel Lourier ◽  
Oliver Lammel ◽  
Berthold Noll ◽  
Manfred Aigner
Keyword(s):  
Heat Release ◽  
High Frequency ◽  
Compressible Flows ◽  
Acoustic Pressure ◽  
Inverse Transformation ◽  
Turbulent Heat ◽  
Thermoacoustic Instability ◽  
Acoustic Feedback ◽  
Fourier Filtering ◽  
Filtering Approach

A method for selective, frequency-resolved analysis of spatially distributed, time-coherent data is introduced. It relies on filtering of Fourier-processed signals with periodic structures in frequency-domain. Therefrom extracted information can be analyzed in both, frequency- and time-domain using an inverse transformation ansatz. In the presented paper, the approach is applied to a laboratory scale, twelve nozzle FLOX®-GT-burner for the investigation of high-frequency thermoacoustic pressure oscillations and limit-cycle mechanisms. The burner is operated at elevated pressure for partially premixed combustion of a hydrogen and natural gas mixture with air. At a certain amount of hydrogen addition to fuel injection, the burner exhibits self-sustained high-frequency thermoacoustic oscillation. This unstable operation is simulated with the fractional step approach SICS (Semi Implicit Characteristic Splitting), a pressure based solver extension of the Finite Volume based research code THETA (Turbulent Heat Release Extension for the TAU Code) for the treatment of weakly compressible flows with combustion. A hybrid LES/URANS simulation delivers time-resolved simulation data of the thermoacoustically unstable operation condition, which is analyzed with the presented SFFFA (Selective Fast Fourier Filtering Approach). Acoustic pressure distribution in the combustion chamber is explicitly resolved and assigned to different characteristic modes by signal decomposition. Furthermore, the SFFFA is used for the analysis of acoustic feedback mechanism by investigating filtered transient heat release, acoustic pressure, velocity and mixture fraction. Coherent structures in flow field and combustion as well as periodic convective processes are resolved and linked to transient acoustic pressure, extensively describing the acoustic feedback of the examined burner configuration.

A One Dimensional, Time Dependent Inlet / Engine Numerical Simulation for Aircraft Propulsion Systems

1997 ◽  
Author(s):  
Doug Garrard ◽  
Milt Davis ◽  
Steve Wehofer ◽  
Gary Cole
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
High Frequency ◽  
Gas Turbine Engine ◽  
Simulation System ◽  
Time Dependent ◽  
Propulsion Systems ◽  
Turbine Engine ◽  
One Dimensional ◽  
Supersonic Inlet

The NASA Lewis Research Center (LeRC) and the Arnold Engineering Development Center (AEDC) have developed a closely coupled computer simulation system that provides a one dimensional, high frequency inlet / engine numerical simulation for aircraft propulsion systems. The simulation system, operating under the LeRC-developed Application Portable Parallel Library (APPL), closely coupled a supersonic inlet with a gas turbine engine. The supersonic inlet was modeled using the Large Perturbation Inlet (LAPIN) computer code, and the gas turbine engine was modeled using the Aerodynamic Turbine Engine Code (ATEC). Both LAPIN and ATEC provide a one dimensional, compressible, time dependent flow solution by solving the one dimensional Euler equations for the conservation of mass, momentum, and energy. Source terms are used to model features such as bleed flows, turbomachinery component characteristics, and inlet subsonic spillage while unstarted. High frequency events, such as compressor surge and inlet unstart, can be simulated with a high degree of fidelity. The simulation system was exercised using a supersonic inlet with sixty percent of the supersonic area contraction occurring internally, and a GE J85-13 turbojet engine.

High-frequency single-electron transport in a quasi-one-dimensional GaAs channel induced by surface acoustic waves

1996 ◽  
Vol 8 (38) ◽  
pp. L531-L539 ◽  
Author(s):  
J M Shilton ◽  
V I Talyanskii ◽  
M Pepper ◽  
D A Ritchie ◽  
J E F Frost ◽  
...  
Keyword(s):  
Electron Transport ◽  
Acoustic Waves ◽  
High Frequency ◽  
Surface Acoustic Waves ◽  
Single Electron ◽  
One Dimensional ◽  
Single Electron Transport

PACKING SUBORDINACY WITH APPLICATION TO SPECTRAL CONTINUITY

2019 ◽  
Vol 108 (2) ◽  
pp. 226-244 ◽  
Author(s):  
V. R. BAZAO ◽  
S. L. CARVALHO ◽  
C. R. DE OLIVEIRA
Keyword(s):  
Continuous Spectrum ◽  
Dimensional Stability ◽  
Schrödinger Operators ◽  
Stability Result ◽  
Schrodinger Operators ◽  
Spectral Measures ◽  
One Dimensional ◽  
Continuity Properties ◽  
Rotation Numbers ◽  
Spectral Continuity

By using methods of subordinacy theory, we study packing continuity properties of spectral measures of discrete one-dimensional Schrödinger operators acting on the whole line. Then we apply these methods to Sturmian operators with rotation numbers of quasibounded density to show that they have purely $\unicode[STIX]{x1D6FC}$-packing continuous spectrum. A dimensional stability result is also mentioned.

High-frequency, 'quantum' and electromechanical effects in quasi-one-dimensional charge density wave conductors

2013 ◽  
Vol 56 (1) ◽  
pp. 29-48 ◽  
Author(s):  
Vadim Ya Pokrovskii ◽  
Sergey G Zybtsev ◽  
Maksim V Nikitin ◽  
Irina G Gorlova ◽  
Venera F Nasretdinova ◽  
...  
Keyword(s):  
Charge Density ◽  
High Frequency ◽  
Charge Density Wave ◽  
Density Wave ◽  
One Dimensional ◽  
Electromechanical Effects
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