One-dimensional turbulence modeling for cylindrical and spherical flows: model formulation and application
Artikel i vetenskaplig tidskrift, 2018

The one-dimensional turbulence (ODT) model resolves a full range of time and length scales and is computationally efficient. ODT has been applied to a wide range of complex multi-scale flows, such as turbulent combustion. Previous ODT comparisons to experimental data have focused mainly on planar flows. Applications to cylindrical flows, such as round jets, have been based on rough analogies, e.g., by exploiting the fortuitous consistency of the similarity scalings of temporally developing planar jets and spatially developing round jets. To obtain a more systematic treatment, a new formulation of the ODT model in cylindrical and spherical coordinates is presented here. The model is written in terms of a geometric factor so that planar, cylindrical, and spherical configurations are represented in the same way. Temporal and spatial versions of the model are presented. A Lagrangian finite-volume implementation is used with a dynamically adaptive mesh. The adaptive mesh facilitates the implementation of cylindrical and spherical versions of the triplet map, which is used to model turbulent advection (eddy events) in the one-dimensional flow coordinate. In cylindrical and spherical coordinates, geometric stretching of the three triplet map images occurs due to the radial dependence of volume, with the stretching being strongest near the centerline. Two triplet map variants, TMA and TMB, are presented. In TMA, the three map images have the same volume, but different radial segment lengths. In TMB, the three map images have the same radial segment lengths, but different segment volumes. Cylindrical results are presented for temporal pipe flow, a spatial nonreacting jet, and a spatial nonreacting jet flame. These results compare very well to direct numerical simulation for the pipe flow, and to experimental data for the jets. The nonreacting jet treatment overpredicts velocity fluctuations near the centerline, due to the geometric stretching of the triplet maps and its effect on the eddy event rate distribution. TMB performs better than TMA. A hybrid planar-TMB (PTMB) approach is also presented, which further improves the results. TMA, TMB, and PTMB are nearly identical in the pipe flow where the key dynamics occur near the wall away from the centerline. The jet flame illustrates effects of variable density and viscosity, including dilatational effects.

One-dimensional turbulence

Turbulence modeling

Cylindrical

ODT

Författare

David Lignell

Brigham Young University

Victoria B. Lansinger

Brigham Young University

Juan Medina

Brandenburgische Technische Universität

Marten Klein

Brandenburgische Technische Universität

Alan R. Kerstein

H. Schmidt

Brandenburgische Technische Universität

Marco Fistler

Chalmers, Mekanik och maritima vetenskaper, Förbränning

Michael Oevermann

Chalmers, Mekanik och maritima vetenskaper, Förbränning

Theoretical and Computational Fluid Dynamics

0935-4964 (ISSN) 1432-2250 (eISSN)

Vol. 32 4 495-520

Ämneskategorier

Teknisk mekanik

Havs- och vattendragsteknik

Strömningsmekanik och akustik

DOI

10.1007/s00162-018-0465-1

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Senast uppdaterat

2018-08-31