Turbulence modification by inertial particles and its influence on the spectral energy budget in planar Couette flow

2015 ◽  
Vol 27 (6) ◽  
pp. 063304 ◽  
Author(s):  
David H. Richter
Keyword(s):  
Couette Flow ◽  
Energy Budget ◽  
Spectral Energy ◽  
Inertial Particles ◽  
Turbulence Modification ◽  
Planar Couette Flow

scholarly journals Frequency-Domain Analysis of the Energy Budget in an Idealized Coupled Ocean–Atmosphere Model

2020 ◽  
Vol 33 (2) ◽  
pp. 707-726 ◽  
Author(s):  
Paige E. Martin ◽  
Brian K. Arbic ◽  
Andrew McC. Hogg ◽  
Andrew E. Kiss ◽  
James R. Munroe ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Time Scales ◽  
Energy Budget ◽  
Western Boundary Current ◽  
Spectral Energy ◽  
Western Boundary ◽  
Intrinsic Variability ◽  
Boundary Current ◽  
Ocean Atmosphere ◽  
Atmosphere Model

AbstractClimate variability is investigated by identifying the energy sources and sinks in an idealized, coupled, ocean–atmosphere model, tuned to mimic the North Atlantic region. The spectral energy budget is calculated in the frequency domain to determine the processes that either deposit energy into or extract energy from each fluid, over time scales from one day up to 100 years. Nonlinear advection of kinetic energy is found to be the dominant source of low-frequency variability in both the ocean and the atmosphere, albeit in differing layers in each fluid. To understand the spatial patterns of the spectral energy budget, spatial maps of certain terms in the spectral energy budget are plotted, averaged over various frequency bands. These maps reveal three dynamically distinct regions: along the western boundary, the western boundary current separation, and the remainder of the domain. The western boundary current separation is found to be a preferred region to energize oceanic variability across a broad range of time scales (from monthly to decadal), while the western boundary itself acts as the dominant sink of energy in the domain at time scales longer than 50 days. This study paves the way for future work, using the same spectral methods, to address the question of forced versus intrinsic variability in a coupled climate system.

Influence of gravity on nonlinear transport in the planar Couette flow

1999 ◽  
Vol 11 (4) ◽  
pp. 893-904 ◽  
Author(s):  
Mohamed Tij ◽  
Vicente Garzó ◽  
Andrés Santos
Keyword(s):  
Couette Flow ◽  
Nonlinear Transport ◽  
Planar Couette Flow

A theorem on stability of a planar Couette flow

1989 ◽  
Vol 41 (11) ◽  
pp. 1328-1335
Author(s):  
V. M. Solopenko
Keyword(s):  
Couette Flow ◽  
Planar Couette Flow

Spectral Energy Budget in Wall Turbulence

1964 ◽  
Vol 7 (2) ◽  
pp. 190 ◽  
Author(s):  
J. L. Lumley
Keyword(s):  
Energy Budget ◽  
Wall Turbulence ◽  
Spectral Energy

Fluid n‐decane undergoing planar Couette flow

1992 ◽  
Vol 97 (10) ◽  
pp. 7687-7694 ◽  
Author(s):  
Paz Padilla ◽  
So/ren Toxvaerd
Keyword(s):  
Couette Flow ◽  
Planar Couette Flow

scholarly journals Applications of a Moist Nonhydrostatic Formulation of the Spectral Energy Budget to Baroclinic Waves. Part I: The Lower-Stratospheric Energy Spectra

2015 ◽  
Vol 72 (5) ◽  
pp. 2090-2108 ◽  
Author(s):  
Jun Peng ◽  
Lifeng Zhang ◽  
Jiping Guan
Keyword(s):  
Kinetic Energy ◽  
Potential Energy ◽  
Energy Budget ◽  
Vertical Flux ◽  
Energy Spectra ◽  
Spectral Energy ◽  
Positive Contribution ◽  
Flux Divergence ◽  
Available Potential Energy ◽  
Baroclinic Waves

Abstract The authors investigate the mesoscale dynamics that produce the lower-stratospheric energy spectra in idealized moist baroclinic waves, using the moist nonhydrostatic formulation of spectral energy budget of kinetic energy and available potential energy by J. Peng et al. The inclusion of moist processes energizes the lower-stratospheric mesoscale, helping to close the gap between observed and simulated energy spectra. In dry baroclinic waves, the lower-stratospheric mesoscale is mainly forced by weak downscale cascades of both horizontal kinetic energy (HKE) and available potential energy (APE) and by a weak conversion of APE to HKE. At wavelengths less than 1000 km, the pressure vertical flux divergence also has a significant positive contribution to the HKE; however, this positive contribution is largely counteracted by the negative HKE vertical flux divergence. In moist baroclinic waves, the lower-stratospheric mesoscale HKE is mainly generated by the pressure and HKE vertical flux divergences. This additional HKE is partly converted to APE and partly removed by diffusion. Another negative contribution to the mesoscale HKE is from the forcing of a visible upscale HKE cascade. Besides the conversion of HKE, however, the three-dimensional divergence also has a significant positive contribution to the mesoscale APE. With these two direct APE sources, the lower-stratospheric mesoscale also undergoes a much stronger upscale APE cascade. These results suggest that both downscale and upscale cascades through the mesoscale are permitted in the real atmosphere and the direct forcing of the mesoscale is available to feed the upscale energy cascade.

scholarly journals Modulation of the turbulence regeneration cycle by inertial particles in planar Couette flow

2018 ◽  
Vol 861 ◽  
pp. 901-929 ◽  
Author(s):  
G. Wang ◽  
D. H. Richter
Keyword(s):  
Reynolds Number ◽  
Couette Flow ◽  
Coherent Structures ◽  
Large Scale ◽  
Relative Length ◽  
Dominant Factor ◽  
Inertial Particles ◽  
Streamwise Vorticity ◽  
Turbulent Coherent Structures ◽  
Regeneration Cycle

Two-way coupled direct numerical simulations are used to investigate the effects of inertial particles on self-sustained, turbulent coherent structures (i.e. the so-called regeneration cycle) in plane Couette flow at low Reynolds number just above the onset of transition. Tests show two limiting behaviours with increasing particle inertia, similar to the results from previous linear stability analyses: low-inertia particles trigger the laminar-to-turbulent instability whereas high-inertia particles tend to stabilize turbulence due to the extra dissipation induced by particle–fluid coupling. Furthermore, it is found that the streamwise coupling between phases is the dominant factor in damping of the turbulence and is highly related to the spatial distribution of the particles. The presence of particles in different turbulent coherent structures (large-scale vortices or large-scale streaks) determines the turbulent kinetic energy of particulate phase, which is related to the particle response time scaled by the turnover time of large-scale vortices. By quantitatively investigating the periodic character of the whole regeneration cycle and the phase difference between linked sub-steps, we show that the presence of inertial particles does not alter the periodic nature of the cycle or the relative length of each of the sub-steps. Instead, high-inertia particles greatly weaken the large-scale vortices as well as the streamwise vorticity stretching and lift-up effects, thereby suppressing the fluctuating amplitude of the large-scale streaks. The primary influence of low-inertia particles, however, is to strengthen the large-scale vortices, which fosters the cycle and ultimately reduces the critical Reynolds number.

Planar Couette Flow in a Single Gas

2003 ◽  
pp. 213-270
Author(s):  
Vicente Garzó ◽  
Andrés Santos
Keyword(s):  
Couette Flow ◽  
Planar Couette Flow
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