Compact finite difference schemes on non-uniform meshes. Application to direct numerical simulations of compressible flows

Gamet, Lionel; Ducros, F.; Nicoud, Franck; Poinsot, Thiérry

doi:10.1002/(sici)1097-0363(19990130)29:2<159::aid-fld781>3.0.co;2-9

Cited by 141 publications

(94 citation statements)

References 20 publications

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“…Equation (1) are discretized on collocated, Cartesian meshes with non-uniform grid spacing. The spatial derivatives are computed with a sixth-order compact scheme reformulated for stretched grids (Lele, 1992;Gamet et al, 1999). A high-order selective artificial dissipation was used to enforce numerical stability while retaining the sixth-order spectral-like resolution at the resolved scales (see Barone, 2003 for details).…”

Section: Model Equationsmentioning

confidence: 99%

Large-eddy simulation of contrail evolution in the vortex phase and its interaction with atmospheric turbulence

et al. 2015

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Abstract. In this work, the evolution of contrails in the vortex and dissipation regimes is studied by means of fully three-dimensional large-eddy simulation (LES) coupled to a Lagrangian particle tracking method to treat the ice phase. In this paper, fine-scale atmospheric turbulence is generated and sustained by means of a stochastic forcing that mimics the properties of stably stratified turbulent flows as those occurring in the upper troposphere and lower stratosphere. The initial flow field is composed of the turbulent background flow and a wake flow obtained from separate LES of the jet regime. Atmospheric turbulence is the main driver of the wake instability and the structure of the resulting wake is sensitive to the intensity of the perturbations, primarily in the vertical direction. A stronger turbulence accelerates the onset of the instability, which results in shorter contrail descent and more effective mixing in the interior of the plume. However, the self-induced turbulence that is produced in the wake after the vortex breakup dominates over background turbulence until the end of the vortex regime and controls the mixing with ambient air. This results in mean microphysical characteristics such as ice mass and optical depth that are slightly affected by the intensity of atmospheric turbulence. However, the background humidity and temperature have a first-order effect on the survival of ice crystals and particle size distribution, which is in line with recent studies.

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Section: Model Equationsmentioning

confidence: 99%

Large-eddy simulation of contrail evolution in the vortex phase and its interaction with atmospheric turbulence

et al. 2015

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“…Equations (4a)-(4d) are discretised on colocated meshes with non-uniform grid spacing using a threedimensional, finite differences Navier-Stokes solver. The spatial derivatives are computed using the sixth order compact scheme by Lele (1992) with modified coefficients to take into account the exact metrics of the mesh (Gamet et al, 1999). Compact schemes are known to provide spectral-like resolution, which is particularly helpful to represent accurately turbulent fluctuations in DNS and LES of turbulent flows (Lele, 1992).…”

Section: S Unterstrasser Et Al: Dimension Of Aircraft Plumes: Effecmentioning

confidence: 99%

Dimension of aircraft exhaust plumes at cruise conditions: effect of wake vortices

et al. 2014

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Abstract. The dispersion of aircraft emissions during the vortex phase is studied using a 3-D LES model with Lagrangian particle tracking. The simulations start with a fully rolled-up vortex pair of a type B747/A340 airplane and the tracer centred around the vortex cores. The tracer dilution and plume extent is studied for a variety of ambient and aircraft parameters until aircraft-induced effects have ceased. For typical upper tropospheric conditions, the impact of stratification is more dominant compared to turbulence intensity or vertical wind shear. Moreover, the sensitivity to the initial tracer distribution was found to be weak. Along the transverse direction, the tracer concentrations can be well approximated by a Gaussian distribution, along the vertical a superposition of three Gaussian distributions is adequate. For the studied parameter range, the vertical plume expansion ranges from 400 m to 550 m and cross-sectional area from 4.0 × 10 4 m 2 to 6 × 10 4 m 2 after six minutes. For validation, selected simulations were compared to an alternative LES model and to in-situ NO-measurements.

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“…These compact schemes become unstable when used with a nonuniform mesh via a coordinate mapping. However, this unstable behavior disappears when integrating the metrics, as we do here, in the definition of the spatial scheme (Le Saout 2003; see also Gamet et al 1999).…”

Section: Spatial Schemementioning

confidence: 99%

Siphon flows and oscillations in long coronal loops due to Alfvén waves

Grappin

Léorat²,

Habbal³

2005

A&A

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Abstract.Using an isothermal axisymmetric MHD model of the solar corona with transparent boundary conditions, we study how coronal loops with apex height between one third and two solar radii react to Alfvén waves generated at the base of the corona. The first response is a steady increase of the density along the excited loops. Density oscillations are also observed, along the apex of the longest loops, that is, those along which waves are substantially damped. Both the steady and the oscillating component scale as the square of the Alfvén wave amplitude, and accordingly, the frequency is double that of the mother wave. Siphon flows may also appear, along short or long loops, depending on whether both or a single foot-point of the loop system is excited.

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Compact finite difference schemes on non-uniform meshes. Application to direct numerical simulations of compressible flows

Cited by 141 publications

References 20 publications

Large-eddy simulation of contrail evolution in the vortex phase and its interaction with atmospheric turbulence

Large-eddy simulation of contrail evolution in the vortex phase and its interaction with atmospheric turbulence

Dimension of aircraft exhaust plumes at cruise conditions: effect of wake vortices

Siphon flows and oscillations in long coronal loops due to Alfvén waves

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