Three-dimensional large-eddy simulations of the early phase of contrail-to-cirrus transition: effects of atmospheric turbulence and radiative transfer

New large-eddy simulations of flow over a flexible plant canopy by Dupont et al. (J. Fluid Mech., 2010, this issue, vol. 652, pp. 5–44) have produced apparently paradoxical results. Work over the last three decades had suggested that turbulent eddies could ‘lock onto’ to the waving frequency of uniform cereal canopies. Their new simulations contradict this view, although a resolution may lie in the essentially three-dimensional nature of the instability process that generates the dominant eddies above plant canopies.

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THE PLUNGING OF HYPERPYCNAL PLUMES ON TILTED BED BY THREE-DIMENSIONAL LARGE-EDDY SIMULATIONS

10.26678/abcm.eptt2020.ept20-0003 ◽

2020 ◽

Author(s):

Felipe Nornberg Schuch ◽

Jorge Silvestrini ◽

Eckart Meiburg ◽

Sylvain Laizet

Keyword(s):

Three Dimensional ◽

Large Eddy Simulations ◽

Large Eddy

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Three-Dimensional Turbulent Vortex Shedding From a Surface-Mounted Square Cylinder: Predictions With Large-Eddy Simulations and URANS

Journal of Fluids Engineering ◽

10.1115/1.4025254 ◽

2014 ◽

Vol 136 (6) ◽

Cited By ~ 6

Author(s):

B. A. Younis ◽

A. Abrishamchi

Keyword(s):

Experimental Data ◽

Turbulence Model ◽

Stokes Equations ◽

Three Dimensional ◽

Large Eddy Simulations ◽

Navier Stokes ◽

Reynolds Stresses ◽

Mean Flow ◽

Navier Stokes Equations ◽

Large Eddy

The paper reports on the prediction of the turbulent flow field around a three-dimensional, surface mounted, square-sectioned cylinder at Reynolds numbers in the range 104–105. The effects of turbulence are accounted for in two different ways: by performing large-eddy simulations (LES) with a Smagorinsky model for the subgrid-scale motions and by solving the unsteady form of the Reynolds-averaged Navier–Stokes equations (URANS) together with a turbulence model to determine the resulting Reynolds stresses. The turbulence model used is a two-equation, eddy-viscosity closure that incorporates a term designed to account for the interactions between the organized mean-flow periodicity and the random turbulent motions. Comparisons with experimental data show that the two approaches yield results that are generally comparable and in good accord with the experimental data. The main conclusion of this work is that the URANS approach, which is considerably less demanding in terms of computer resources than LES, can reliably be used for the prediction of unsteady separated flows provided that the effects of organized mean-flow unsteadiness on the turbulence are properly accounted for in the turbulence model.

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Study of Afterburning in Solid Rocket Booster Jet: Towards a Model for Afterburning in Large Eddy Simulations

Volume 1D, Symposia: Transport Phenomena in Mixing; Turbulent Flows; Urban Fluid Mechanics; Fluid Dynamic Behavior of Complex Particles; Analysis of Elementary Processes in Dispersed Multiphase Flows; Multiphase Flow With Heat/Mass Transfer in Process Technology; Fluid Mechanics of Aircraft and Rocket Emissions and Their Environmental Impacts; High Performance CFD Computation; Performance of Multiphase Flow Systems; Wind Energy; Uncertainty Quantification in Flow Measurements and Simulations ◽

10.1115/fedsm2014-21536 ◽

2014 ◽

Author(s):

Adèle Poubeau ◽

Roberto Paoli ◽

Daniel Cariolle

Keyword(s):

Three Dimensional ◽

Axial Direction ◽

Large Eddy Simulations ◽

Chemical Mechanism ◽

Computational Domain ◽

Time Step ◽

Simple Method ◽

Large Eddy ◽

Solid Rocket ◽

Comparison Of The Results

This paper focuses on two decisive steps towards Large Eddy Simulation of a solid rocket booster jet. First, three-dimensional Large Eddy Simulations of a non-reactive booster jet including the nozzle were obtained at flight conditions of 20 km of altitude. A particularly long computational domain (400 nozzle exit diameters in the jet axial direction) was simulated, thanks to an innovative local time-stepping method via coupling multi instances of a fluid solver. The dynamics of the jet is analysed and comparison of the results with previous knowledge validates the simulations and confirms that this computational setup can be applied for Large Eddy Simulations of a reactive booster jet. The second part of this paper details the implementation of a simple method to study the hot plume chemistry. Despite its limitations, it is accurate enough to observe the various steps of the chemical mechanism and assess the effect of uncertainties of the rate parameters on chlorine reactions. It was also used to reduce the set of chemical reactions into a short scheme involving a minimum of species and having a limited impact on the physical time step of the Large Eddy Simulations.

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Large-Eddy Simulations of Three-Dimensional Spatially-Developing Round Jets

Direct and Large-Eddy Simulation II - ERCOFTAC Series ◽

10.1007/978-94-011-5624-0_4 ◽

1997 ◽

pp. 35-46 ◽

Cited By ~ 15

Author(s):

Gérald Urbin ◽

Olivier Métais

Keyword(s):

Three Dimensional ◽

Large Eddy Simulations ◽

Round Jets ◽

Large Eddy

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Reliable and Accurate Prediction of Three-Dimensional Separation in Asymmetric Diffusers Using Large-Eddy Simulation

Volume 7: Turbomachinery, Parts A and B ◽

10.1115/gt2009-60110 ◽

2009 ◽

Cited By ~ 3

Author(s):

Hayder Schneider ◽

Dominic von Terzi ◽

Hans-Jo¨rg Bauer ◽

Wolfgang Rodi

Keyword(s):

Experimental Data ◽

Reverse Flow ◽

Separation Bubble ◽

Pressure Coefficient ◽

Three Dimensional ◽

Large Eddy Simulations ◽

Navier Stokes ◽

Eddy Simulation ◽

Large Eddy ◽

The Impact

Reynolds-Averaged Navier-Stokes (RANS) calculations and Large-Eddy Simulations (LES) of the flow in two asymmetric three-dimensional diffusers were performed. The numerical setup was chosen to be in compliance with previous experiments. The aim of the present study is to find the least expensive method to compute reliably and accurately the impact of geometric sensitivity on the flow. RANS calculations fail to predict both the extent and location of the three-dimensional separation bubble. In contrast, LES is able to determine the amount of reverse flow and the pressure coefficient within the accuracy of experimental data.

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