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@PHDTHESIS{Werner:959034,
author = {Werner, Michael},
othercontributors = {Schröder, Wolfgang and Rein, Martin},
title = {{N}umerische {U}ntersuchung der {W}irbel-{W}irbel- und
{W}irbel-{S}toß-{I}nteraktion in transsonischen
{S}trömungen},
school = {Rheinisch-Westfälische Technische Hochschule Aachen},
type = {Dissertation},
address = {Aachen},
publisher = {RWTH Aachen University},
reportid = {RWTH-2023-05542, DLR-FB-2023-7},
pages = {1 Online-Ressource : Illustrationen, Diagramme},
year = {2023},
note = {Veröffentlicht auf dem Publikationsserver der RWTH Aachen
University. - Überarbeitete Auflage mit ergänzter
Nomenklatur verfügbar; Dissertation,
Rheinisch-Westfälische Technische Hochschule Aachen, 2023},
abstract = {The flow topology around modern multiple-swept delta wings
at transonic flow speeds is dominated by strong longitudinal
vortices. Depending on the flow conditions, these vortices
can interact with each other or with shocks that form above
the wing. In the scope of this work, these vortex-vortex-
and vortex-shock-interactions are investigated numerically
using the DLR-TAU code. Special emphasis is placed on the
stability of the vortices with respect to vortex breakdown.
The majority of the numerical simulations is based on
conventional URANS simulations. For selected cases, a
scale-resolving IDDES method is also applied. The first part
of this work deals with the flow around a generic
multiple-swept delta wing, the DLR-F22 model. The flow
topology at the DLR-F22 model is dominated by several
primary vortices. Additionally, at transonic speeds shocks
occur above the wing. During the study the influence of the
angle of attack and angle of sideslip as well as that of the
freestream Mach number and the planform of the model on the
resulting vortex interactions is investigated. Over a broad
range of angle of attack as well as freestream Mach number,
strong vortex-vortex interactions, including vortex merging,
are observed. Additionally, at transonic conditions,
shock-induced vortex-breakdown occurs above the model.In the
second part of this work, the interaction of generic
longitudinal vortices with an oblique shock is investigated
using a simple ramp flow. In a first step, the influence of
the circulation and the axial velocity of the vortex on the
stability against vortex breakdown due to the vortex-shock
interaction is analyzed by means of a parametric study. In a
second step, a second vortex is introduced into the flow
field to investigate vortex-vortex interaction. Depending on
the distance between the vortices and the relative sense of
rotation, either a stabilisation or a destabilisation of the
main vortex is observed. Based on the numerical results, a
revised vortex breakdown criterion is defined and validated
using data from the literature. The predictions of the new
criterion prove to be more accurate over a wide range of
Mach numbers than those of previously existing criteria.
Additionally, a global stability analysis framework is
implemented and applied to the case of
vortex-shock-interaction for the first time. A comparison
with unsteady simulations is used to confirm the stability
boundary identified by the global stability analysis and
thus the applicability of the approach to the case of
vortex-shock-interaction.},
cin = {415110},
ddc = {620},
cid = {$I:(DE-82)415110_20140620$},
typ = {PUB:(DE-HGF)11},
doi = {10.18154/RWTH-2023-05542},
url = {https://publications.rwth-aachen.de/record/959034},
}
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