Dynamic Mode Decomposition Applied to a Detached-Eddy Simulation of Separated Nozzle Flow
Paper in proceeding, 2017

The paper presents results from a Dynamic Mode Decomposition (DMD) of data from a Detached Eddy Simulation (DES) of a separated flow inside a truncated ideal nozzle. Two cases of different pressure ratios were studied. Sparsity-Promoting algorithm along with computed optimal mode amplitudes were used to determine importance of individual modes. An ovalization mode (a mode with azimuthal wavenumber m = 2) was found for the lower pressure ratio and was linked to a peak in spectra from probe data. At the higher pressure ratio a helical mode (azimuthal wavenumber m = 1) was found and linked to a peak in spectra from probe data and the nozzle side-load spectrum. The paper shows the potential for using DMD for separated nozzle flows to identify im- portant periodic flow behavior but also underlines the challenges that the method faces, such as noise from resolved turbulence and difficulty identifying modes within the broad low-frequency-range of the side-load spectrum.

Detached Eddy Simulation

Nozzle Flow

Separated Nozzle Flow

Dynamic Mode Decomposition


Ragnar Larusson

Chalmers, Applied Mechanics, Fluid Dynamics

Markus Olander Burak

Chalmers, Applied Mechanics, Fluid Dynamics

Niklas Andersson

Chalmers, Applied Mechanics, Fluid Dynamics

Jan Östlund

GKN Aerospace Services

978-162410447-3 (ISBN)

55th AIAA Aerospace Sciences Meeting
Grapevine, USA,

Subject Categories

Aerospace Engineering

Fluid Mechanics and Acoustics


C3SE (Chalmers Centre for Computational Science and Engineering)



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