---
_id: '5943'
abstract:
- lang: eng
text: The hairpin instability of a jet in a crossflow (JICF) for a low jet-to-crossflow
velocity ratio is investigated experimentally for a velocity ratio range of R
∈ (0.14, 0.75) and crossflow Reynolds numbers ReD ∈ (260, 640). From spectral
analysis we characterize the Strouhal number and amplitude of the hairpin instability
as a function of R and ReD. We demonstrate that the dynamics of the hairpins is
well described by the Landau model, and, hence, that the instability occurs through
Hopf bifurcation, similarly to other hydrodynamical oscillators such as wake behind
different bluff bodies. Using the Landau model, we determine the precise threshold
values of hairpin shedding. We also study the spatial dependence of this hydrodynamical
instability, which shows a global behaviour.
article_processing_charge: No
article_type: original
author:
- first_name: Lukasz
full_name: Klotz, Lukasz
id: 2C9AF1C2-F248-11E8-B48F-1D18A9856A87
last_name: Klotz
orcid: 0000-0003-1740-7635
- first_name: Konrad
full_name: Gumowski, Konrad
last_name: Gumowski
- first_name: José Eduardo
full_name: Wesfreid, José Eduardo
last_name: Wesfreid
citation:
ama: Klotz L, Gumowski K, Wesfreid JE. Experiments on a jet in a crossflow in the
low-velocity-ratio regime. Journal of Fluid Mechanics. 2019;863:386-406.
doi:10.1017/jfm.2018.974
apa: Klotz, L., Gumowski, K., & Wesfreid, J. E. (2019). Experiments on a jet
in a crossflow in the low-velocity-ratio regime. Journal of Fluid Mechanics.
Cambridge University Press. https://doi.org/10.1017/jfm.2018.974
chicago: Klotz, Lukasz, Konrad Gumowski, and José Eduardo Wesfreid. “Experiments
on a Jet in a Crossflow in the Low-Velocity-Ratio Regime.” Journal of Fluid
Mechanics. Cambridge University Press, 2019. https://doi.org/10.1017/jfm.2018.974.
ieee: L. Klotz, K. Gumowski, and J. E. Wesfreid, “Experiments on a jet in a crossflow
in the low-velocity-ratio regime,” Journal of Fluid Mechanics, vol. 863.
Cambridge University Press, pp. 386–406, 2019.
ista: Klotz L, Gumowski K, Wesfreid JE. 2019. Experiments on a jet in a crossflow
in the low-velocity-ratio regime. Journal of Fluid Mechanics. 863, 386–406.
mla: Klotz, Lukasz, et al. “Experiments on a Jet in a Crossflow in the Low-Velocity-Ratio
Regime.” Journal of Fluid Mechanics, vol. 863, Cambridge University Press,
2019, pp. 386–406, doi:10.1017/jfm.2018.974.
short: L. Klotz, K. Gumowski, J.E. Wesfreid, Journal of Fluid Mechanics 863 (2019)
386–406.
date_created: 2019-02-10T22:59:15Z
date_published: 2019-03-25T00:00:00Z
date_updated: 2023-08-24T14:43:13Z
day: '25'
department:
- _id: BjHo
doi: 10.1017/jfm.2018.974
ec_funded: 1
external_id:
arxiv:
- '1902.07931'
isi:
- '000526029100016'
intvolume: ' 863'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1902.07931
month: '03'
oa: 1
oa_version: Preprint
page: 386-406
project:
- _id: 260C2330-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '754411'
name: ISTplus - Postdoctoral Fellowships
publication: Journal of Fluid Mechanics
publication_status: published
publisher: Cambridge University Press
quality_controlled: '1'
scopus_import: '1'
status: public
title: Experiments on a jet in a crossflow in the low-velocity-ratio regime
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 863
year: '2019'
...
---
_id: '5878'
abstract:
- lang: eng
text: We consider the motion of a droplet bouncing on a vibrating bath of the same
fluid in the presence of a central potential. We formulate a rotation symmetry-reduced
description of this system, which allows for the straightforward application of
dynamical systems theory tools. As an illustration of the utility of the symmetry
reduction, we apply it to a model of the pilot-wave system with a central harmonic
force. We begin our analysis by identifying local bifurcations and the onset of
chaos. We then describe the emergence of chaotic regions and their merging bifurcations,
which lead to the formation of a global attractor. In this final regime, the droplet’s
angular momentum spontaneously changes its sign as observed in the experiments
of Perrard et al.
article_number: '013122'
article_processing_charge: No
article_type: original
author:
- first_name: Nazmi B
full_name: Budanur, Nazmi B
id: 3EA1010E-F248-11E8-B48F-1D18A9856A87
last_name: Budanur
orcid: 0000-0003-0423-5010
- first_name: Marc
full_name: Fleury, Marc
last_name: Fleury
citation:
ama: 'Budanur NB, Fleury M. State space geometry of the chaotic pilot-wave hydrodynamics.
Chaos: An Interdisciplinary Journal of Nonlinear Science. 2019;29(1). doi:10.1063/1.5058279'
apa: 'Budanur, N. B., & Fleury, M. (2019). State space geometry of the chaotic
pilot-wave hydrodynamics. Chaos: An Interdisciplinary Journal of Nonlinear
Science. AIP Publishing. https://doi.org/10.1063/1.5058279'
chicago: 'Budanur, Nazmi B, and Marc Fleury. “State Space Geometry of the Chaotic
Pilot-Wave Hydrodynamics.” Chaos: An Interdisciplinary Journal of Nonlinear
Science. AIP Publishing, 2019. https://doi.org/10.1063/1.5058279.'
ieee: 'N. B. Budanur and M. Fleury, “State space geometry of the chaotic pilot-wave
hydrodynamics,” Chaos: An Interdisciplinary Journal of Nonlinear Science,
vol. 29, no. 1. AIP Publishing, 2019.'
ista: 'Budanur NB, Fleury M. 2019. State space geometry of the chaotic pilot-wave
hydrodynamics. Chaos: An Interdisciplinary Journal of Nonlinear Science. 29(1),
013122.'
mla: 'Budanur, Nazmi B., and Marc Fleury. “State Space Geometry of the Chaotic Pilot-Wave
Hydrodynamics.” Chaos: An Interdisciplinary Journal of Nonlinear Science,
vol. 29, no. 1, 013122, AIP Publishing, 2019, doi:10.1063/1.5058279.'
short: 'N.B. Budanur, M. Fleury, Chaos: An Interdisciplinary Journal of Nonlinear
Science 29 (2019).'
date_created: 2019-01-23T08:35:09Z
date_published: 2019-01-22T00:00:00Z
date_updated: 2023-08-25T10:16:11Z
day: '22'
department:
- _id: BjHo
doi: 10.1063/1.5058279
external_id:
arxiv:
- '1812.09011'
isi:
- '000457409100028'
intvolume: ' 29'
isi: 1
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1812.09011
month: '01'
oa: 1
oa_version: Preprint
publication: 'Chaos: An Interdisciplinary Journal of Nonlinear Science'
publication_identifier:
eissn:
- 1089-7682
issn:
- 1054-1500
publication_status: published
publisher: AIP Publishing
quality_controlled: '1'
related_material:
link:
- relation: erratum
url: https://aip.scitation.org/doi/abs/10.1063/1.5097157
scopus_import: '1'
status: public
title: State space geometry of the chaotic pilot-wave hydrodynamics
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 29
year: '2019'
...
---
_id: '6413'
abstract:
- lang: eng
text: Phase-field methods have long been used to model the flow of immiscible fluids.
Their ability to naturally capture interface topological changes is widely recognized,
but their accuracy in simulating flows of real fluids in practical geometries
is not established. We here quantitatively investigate the convergence of the
phase-field method to the sharp-interface limit with simulations of two-phase
pipe flow. We focus on core-annular flows, in which a highly viscous fluid is
lubricated by a less viscous fluid, and validate our simulations with an analytic
laminar solution, a formal linear stability analysis and also in the fully nonlinear
regime. We demonstrate the ability of the phase-field method to accurately deal
with non-rectangular geometry, strong advection, unsteady fluctuations and large
viscosity contrast. We argue that phase-field methods are very promising for quantitatively
studying moderately turbulent flows, especially at high concentrations of the
disperse phase.
article_processing_charge: No
article_type: original
author:
- first_name: Baofang
full_name: Song, Baofang
last_name: Song
- first_name: Carlos
full_name: Plana, Carlos
last_name: Plana
- first_name: Jose M
full_name: Lopez Alonso, Jose M
id: 40770848-F248-11E8-B48F-1D18A9856A87
last_name: Lopez Alonso
orcid: 0000-0002-0384-2022
- first_name: Marc
full_name: Avila, Marc
last_name: Avila
citation:
ama: Song B, Plana C, Lopez Alonso JM, Avila M. Phase-field simulation of core-annular
pipe flow. International Journal of Multiphase Flow. 2019;117:14-24. doi:10.1016/j.ijmultiphaseflow.2019.04.027
apa: Song, B., Plana, C., Lopez Alonso, J. M., & Avila, M. (2019). Phase-field
simulation of core-annular pipe flow. International Journal of Multiphase Flow.
Elsevier. https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027
chicago: Song, Baofang, Carlos Plana, Jose M Lopez Alonso, and Marc Avila. “Phase-Field
Simulation of Core-Annular Pipe Flow.” International Journal of Multiphase
Flow. Elsevier, 2019. https://doi.org/10.1016/j.ijmultiphaseflow.2019.04.027.
ieee: B. Song, C. Plana, J. M. Lopez Alonso, and M. Avila, “Phase-field simulation
of core-annular pipe flow,” International Journal of Multiphase Flow, vol.
117. Elsevier, pp. 14–24, 2019.
ista: Song B, Plana C, Lopez Alonso JM, Avila M. 2019. Phase-field simulation of
core-annular pipe flow. International Journal of Multiphase Flow. 117, 14–24.
mla: Song, Baofang, et al. “Phase-Field Simulation of Core-Annular Pipe Flow.” International
Journal of Multiphase Flow, vol. 117, Elsevier, 2019, pp. 14–24, doi:10.1016/j.ijmultiphaseflow.2019.04.027.
short: B. Song, C. Plana, J.M. Lopez Alonso, M. Avila, International Journal of
Multiphase Flow 117 (2019) 14–24.
date_created: 2019-05-13T07:58:35Z
date_published: 2019-08-01T00:00:00Z
date_updated: 2023-08-25T10:19:55Z
day: '01'
department:
- _id: BjHo
doi: 10.1016/j.ijmultiphaseflow.2019.04.027
external_id:
arxiv:
- '1902.07351'
isi:
- '000474496000002'
intvolume: ' 117'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1902.07351
month: '08'
oa: 1
oa_version: Preprint
page: 14-24
publication: International Journal of Multiphase Flow
publication_identifier:
issn:
- '03019322'
publication_status: published
publisher: Elsevier
quality_controlled: '1'
scopus_import: '1'
status: public
title: Phase-field simulation of core-annular pipe flow
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 117
year: '2019'
...
---
_id: '6978'
abstract:
- lang: eng
text: In pipes and channels, the onset of turbulence is initially dominated by localizedtransients, which lead to sustained turbulence through their collective dynamics. In thepresent
work, we study numerically the localized turbulence in pipe flow and elucidate
astate space structure that gives rise to transient chaos. Starting from the basin
boundaryseparating laminar and turbulent flow, we identify transverse homoclinic orbits, thepresence
of which necessitates a homoclinic tangle and chaos. A direct consequence ofthe
homoclinic tangle is the fractal nature of the laminar-turbulent boundary, which
wasconjectured in various earlier studies. By mapping the transverse intersections
between thestable and unstable manifold of a periodic orbit, we identify the gateways
that promote anescape from turbulence.
acknowledged_ssus:
- _id: ScienComp
article_processing_charge: No
article_type: original
author:
- first_name: Nazmi B
full_name: Budanur, Nazmi B
id: 3EA1010E-F248-11E8-B48F-1D18A9856A87
last_name: Budanur
orcid: 0000-0003-0423-5010
- first_name: Akshunna
full_name: Dogra, Akshunna
last_name: Dogra
- first_name: Björn
full_name: Hof, Björn
id: 3A374330-F248-11E8-B48F-1D18A9856A87
last_name: Hof
orcid: 0000-0003-2057-2754
citation:
ama: Budanur NB, Dogra A, Hof B. Geometry of transient chaos in streamwise-localized
pipe flow turbulence. Physical Review Fluids. 2019;4(10):102401. doi:10.1103/PhysRevFluids.4.102401
apa: Budanur, N. B., Dogra, A., & Hof, B. (2019). Geometry of transient chaos
in streamwise-localized pipe flow turbulence. Physical Review Fluids. American
Physical Society. https://doi.org/10.1103/PhysRevFluids.4.102401
chicago: Budanur, Nazmi B, Akshunna Dogra, and Björn Hof. “Geometry of Transient
Chaos in Streamwise-Localized Pipe Flow Turbulence.” Physical Review Fluids.
American Physical Society, 2019. https://doi.org/10.1103/PhysRevFluids.4.102401.
ieee: N. B. Budanur, A. Dogra, and B. Hof, “Geometry of transient chaos in streamwise-localized
pipe flow turbulence,” Physical Review Fluids, vol. 4, no. 10. American
Physical Society, p. 102401, 2019.
ista: Budanur NB, Dogra A, Hof B. 2019. Geometry of transient chaos in streamwise-localized
pipe flow turbulence. Physical Review Fluids. 4(10), 102401.
mla: Budanur, Nazmi B., et al. “Geometry of Transient Chaos in Streamwise-Localized
Pipe Flow Turbulence.” Physical Review Fluids, vol. 4, no. 10, American
Physical Society, 2019, p. 102401, doi:10.1103/PhysRevFluids.4.102401.
short: N.B. Budanur, A. Dogra, B. Hof, Physical Review Fluids 4 (2019) 102401.
date_created: 2019-11-04T10:04:01Z
date_published: 2019-10-01T00:00:00Z
date_updated: 2023-08-30T07:20:03Z
day: '01'
department:
- _id: BjHo
doi: 10.1103/PhysRevFluids.4.102401
external_id:
arxiv:
- '1810.02211'
isi:
- '000493510400001'
intvolume: ' 4'
isi: 1
issue: '10'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1810.02211
month: '10'
oa: 1
oa_version: Preprint
page: '102401'
publication: Physical Review Fluids
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
scopus_import: '1'
status: public
title: Geometry of transient chaos in streamwise-localized pipe flow turbulence
type: journal_article
user_id: 4359f0d1-fa6c-11eb-b949-802e58b17ae8
volume: 4
year: '2019'
...
---
_id: '7397'
abstract:
- lang: eng
text: Polymer additives can substantially reduce the drag of turbulent flows and
the upperlimit, the so called “maximum drag reduction” (MDR) asymptote is universal,
i.e. inde-pendent of the type of polymer and solvent used. Until recently, the
consensus was that,in this limit, flows are in a marginal state where only a minimal
level of turbulence activ-ity persists. Observations in direct numerical simulations
using minimal sized channelsappeared to support this view and reported long “hibernation” periods where turbu-lence
is marginalized. In simulations of pipe flow we find that, indeed, with increasingWeissenberg
number (Wi), turbulence expresses long periods of hibernation if the domainsize
is small. However, with increasing pipe length, the temporal hibernation continuouslyalters
to spatio-temporal intermittency and here the flow consists of turbulent puffs
sur-rounded by laminar flow. Moreover, upon an increase in Wi, the flow fully
relaminarises,in agreement with recent experiments. At even larger Wi, a different
instability is en-countered causing a drag increase towards MDR. Our findings
hence link earlier minimalflow unit simulations with recent experiments and confirm
that the addition of polymersinitially suppresses Newtonian turbulence and leads
to a reverse transition. The MDRstate on the other hand results from a separate
instability and the underlying dynamicscorresponds to the recently proposed state
of elasto-inertial-turbulence (EIT).
article_processing_charge: No
article_type: original
author:
- first_name: Jose M
full_name: Lopez Alonso, Jose M
id: 40770848-F248-11E8-B48F-1D18A9856A87
last_name: Lopez Alonso
orcid: 0000-0002-0384-2022
- first_name: George H
full_name: Choueiri, George H
id: 448BD5BC-F248-11E8-B48F-1D18A9856A87
last_name: Choueiri
- first_name: Björn
full_name: Hof, Björn
id: 3A374330-F248-11E8-B48F-1D18A9856A87
last_name: Hof
orcid: 0000-0003-2057-2754
citation:
ama: Lopez Alonso JM, Choueiri GH, Hof B. Dynamics of viscoelastic pipe flow at
low Reynolds numbers in the maximum drag reduction limit. Journal of Fluid
Mechanics. 2019;874:699-719. doi:10.1017/jfm.2019.486
apa: Lopez Alonso, J. M., Choueiri, G. H., & Hof, B. (2019). Dynamics of viscoelastic
pipe flow at low Reynolds numbers in the maximum drag reduction limit. Journal
of Fluid Mechanics. CUP. https://doi.org/10.1017/jfm.2019.486
chicago: Lopez Alonso, Jose M, George H Choueiri, and Björn Hof. “Dynamics of Viscoelastic
Pipe Flow at Low Reynolds Numbers in the Maximum Drag Reduction Limit.” Journal
of Fluid Mechanics. CUP, 2019. https://doi.org/10.1017/jfm.2019.486.
ieee: J. M. Lopez Alonso, G. H. Choueiri, and B. Hof, “Dynamics of viscoelastic
pipe flow at low Reynolds numbers in the maximum drag reduction limit,” Journal
of Fluid Mechanics, vol. 874. CUP, pp. 699–719, 2019.
ista: Lopez Alonso JM, Choueiri GH, Hof B. 2019. Dynamics of viscoelastic pipe flow
at low Reynolds numbers in the maximum drag reduction limit. Journal of Fluid
Mechanics. 874, 699–719.
mla: Lopez Alonso, Jose M., et al. “Dynamics of Viscoelastic Pipe Flow at Low Reynolds
Numbers in the Maximum Drag Reduction Limit.” Journal of Fluid Mechanics,
vol. 874, CUP, 2019, pp. 699–719, doi:10.1017/jfm.2019.486.
short: J.M. Lopez Alonso, G.H. Choueiri, B. Hof, Journal of Fluid Mechanics 874
(2019) 699–719.
date_created: 2020-01-29T16:05:19Z
date_published: 2019-09-10T00:00:00Z
date_updated: 2023-09-06T15:36:36Z
day: '10'
department:
- _id: BjHo
doi: 10.1017/jfm.2019.486
external_id:
arxiv:
- '1808.04080'
isi:
- '000475349900001'
intvolume: ' 874'
isi: 1
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1808.04080
month: '09'
oa: 1
oa_version: Preprint
page: 699-719
publication: Journal of Fluid Mechanics
publication_identifier:
eissn:
- 1469-7645
issn:
- 0022-1120
publication_status: published
publisher: CUP
quality_controlled: '1'
scopus_import: '1'
status: public
title: Dynamics of viscoelastic pipe flow at low Reynolds numbers in the maximum drag
reduction limit
type: journal_article
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 874
year: '2019'
...
---
_id: '6957'
abstract:
- lang: eng
text: "In many shear flows like pipe flow, plane Couette flow, plane Poiseuille
flow, etc. turbulence emerges subcritically. Here, when subjected to strong enough
perturbations, the flow becomes turbulent in spite of the laminar base flow being
linearly stable. The nature of this instability has puzzled the scientific community
for decades. At onset, turbulence appears in localized patches and flows are spatio-temporally
intermittent. In pipe flow the localized turbulent structures are referred to
as puffs and in planar flows like plane Couette and channel flow, patches arise
in the form of localized oblique bands. In this thesis, we study the onset of
turbulence in channel flow in direct numerical simulations from a dynamical system
theory perspective, as well as by performing experiments in a large aspect ratio
channel.\r\n\r\nThe aim of the experimental work is to determine the critical
Reynolds number where turbulence first becomes sustained. Recently, the onset
of turbulence has been described in analogy to absorbing state phase transition
(i.e. directed percolation). In particular, it has been shown that the critical
point can be estimated from the competition between spreading and decay processes.
Here, by performing experiments, we identify the mechanisms underlying turbulence
proliferation in channel flow and find the critical Reynolds number, above which
turbulence becomes sustained. Above the critical point, the continuous growth
at the tip of the stripes outweighs the stochastic shedding of turbulent patches
at the tail and the stripes expand. For growing stripes, the probability to decay
decreases while the probability of stripe splitting increases. Consequently, and
unlike for the puffs in pipe flow, neither of these two processes is time-independent
i.e. memoryless. Coupling between stripe expansion and creation of new stripes
via splitting leads to a significantly lower critical point ($Re_c=670+/-10$)
than most earlier studies suggest. \r\n\r\nWhile the above approach sheds light
on how turbulence first becomes sustained, it provides no insight into the origin
of the stripes themselves. In the numerical part of the thesis we investigate
how turbulent stripes form from invariant solutions of the Navier-Stokes equations.
The origin of these turbulent stripes can be identified by applying concepts from
the dynamical system theory. In doing so, we identify the exact coherent structures
underlying stripes and their bifurcations and how they give rise to the turbulent
attractor in phase space. We first report a family of localized nonlinear traveling
wave solutions of the Navier-Stokes equations in channel flow. These solutions
show structural similarities with turbulent stripes in experiments like obliqueness,
quasi-streamwise streaks and vortices, etc. A parametric study of these traveling
wave solution is performed, with parameters like Reynolds number, stripe tilt
angle and domain size, including the stability of the solutions. These solutions
emerge through saddle-node bifurcations and form a phase space skeleton for the
turbulent stripes observed in the experiments. The lower branches of these TW
solutions at different tilt angles undergo Hopf bifurcation and new solutions
branches of relative periodic orbits emerge. These RPO solutions do not belong
to the same family and therefore the routes to chaos for different angles are
different. \r\n\r\nIn shear flows, turbulence at onset is transient in nature.
\ Consequently,turbulence can not be tracked to lower Reynolds numbers, where
the dynamics may simplify. Before this happens, turbulence becomes short-lived
and laminarizes. In the last part of the thesis, we show that using numerical
simulations we can continue turbulent stripes in channel flow past the 'relaminarization
barrier' all the way to their origin. Here, turbulent stripe dynamics simplifies
and the fluctuations are no longer stochastic and the stripe settles down to a
relative periodic orbit. This relative periodic orbit originates from the aforementioned
traveling wave solutions. Starting from the relative periodic orbit, a small increase
in speed i.e. Reynolds number gives rise to chaos and the attractor dimension
sharply increases in contrast to the classical transition scenario where the instabilities
affect the flow globally and give rise to much more gradual route to turbulence."
alternative_title:
- ISTA Thesis
article_processing_charge: No
author:
- first_name: Chaitanya S
full_name: Paranjape, Chaitanya S
id: 3D85B7C4-F248-11E8-B48F-1D18A9856A87
last_name: Paranjape
citation:
ama: Paranjape CS. Onset of turbulence in plane Poiseuille flow. 2019. doi:10.15479/AT:ISTA:6957
apa: Paranjape, C. S. (2019). Onset of turbulence in plane Poiseuille flow.
Institute of Science and Technology Austria. https://doi.org/10.15479/AT:ISTA:6957
chicago: Paranjape, Chaitanya S. “Onset of Turbulence in Plane Poiseuille Flow.”
Institute of Science and Technology Austria, 2019. https://doi.org/10.15479/AT:ISTA:6957.
ieee: C. S. Paranjape, “Onset of turbulence in plane Poiseuille flow,” Institute
of Science and Technology Austria, 2019.
ista: Paranjape CS. 2019. Onset of turbulence in plane Poiseuille flow. Institute
of Science and Technology Austria.
mla: Paranjape, Chaitanya S. Onset of Turbulence in Plane Poiseuille Flow.
Institute of Science and Technology Austria, 2019, doi:10.15479/AT:ISTA:6957.
short: C.S. Paranjape, Onset of Turbulence in Plane Poiseuille Flow, Institute of
Science and Technology Austria, 2019.
date_created: 2019-10-22T12:08:43Z
date_published: 2019-10-24T00:00:00Z
date_updated: 2023-09-07T12:53:25Z
day: '24'
ddc:
- '532'
degree_awarded: PhD
department:
- _id: BjHo
doi: 10.15479/AT:ISTA:6957
file:
- access_level: closed
checksum: 7ba298ba0ce7e1d11691af6b8eaf0a0a
content_type: application/zip
creator: cparanjape
date_created: 2019-10-23T09:54:43Z
date_updated: 2020-07-14T12:47:46Z
file_id: '6962'
file_name: Chaitanya_Paranjape_source_files_tex_figures.zip
file_size: 45828099
relation: source_file
- access_level: open_access
checksum: 642697618314e31ac31392da7909c2d9
content_type: application/pdf
creator: cparanjape
date_created: 2019-10-23T10:37:09Z
date_updated: 2020-07-14T12:47:46Z
file_id: '6963'
file_name: Chaitanya_Paranjape_Thesis.pdf
file_size: 19504197
relation: main_file
file_date_updated: 2020-07-14T12:47:46Z
has_accepted_license: '1'
keyword:
- Instabilities
- Turbulence
- Nonlinear dynamics
language:
- iso: eng
month: '10'
oa: 1
oa_version: Published Version
page: '138'
publication_identifier:
eissn:
- 2663-337X
publication_status: published
publisher: Institute of Science and Technology Austria
status: public
supervisor:
- first_name: Björn
full_name: Hof, Björn
id: 3A374330-F248-11E8-B48F-1D18A9856A87
last_name: Hof
orcid: 0000-0003-2057-2754
title: Onset of turbulence in plane Poiseuille flow
type: dissertation
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
year: '2019'
...
---
_id: '7197'
abstract:
- lang: eng
text: During bacterial cell division, the tubulin-homolog FtsZ forms a ring-like
structure at the center of the cell. This Z-ring not only organizes the division
machinery, but treadmilling of FtsZ filaments was also found to play a key role
in distributing proteins at the division site. What regulates the architecture,
dynamics and stability of the Z-ring is currently unknown, but FtsZ-associated
proteins are known to play an important role. Here, using an in vitro reconstitution
approach, we studied how the well-conserved protein ZapA affects FtsZ treadmilling
and filament organization into large-scale patterns. Using high-resolution fluorescence
microscopy and quantitative image analysis, we found that ZapA cooperatively increases
the spatial order of the filament network, but binds only transiently to FtsZ
filaments and has no effect on filament length and treadmilling velocity. Together,
our data provides a model for how FtsZ-associated proteins can increase the precision
and stability of the bacterial cell division machinery in a switch-like manner.
acknowledged_ssus:
- _id: LifeSc
- _id: Bio
article_number: '5744'
article_processing_charge: No
article_type: original
author:
- first_name: Paulo R
full_name: Dos Santos Caldas, Paulo R
id: 38FCDB4C-F248-11E8-B48F-1D18A9856A87
last_name: Dos Santos Caldas
orcid: 0000-0001-6730-4461
- first_name: Maria D
full_name: Lopez Pelegrin, Maria D
id: 319AA9CE-F248-11E8-B48F-1D18A9856A87
last_name: Lopez Pelegrin
- first_name: Daniel J. G.
full_name: Pearce, Daniel J. G.
last_name: Pearce
- first_name: Nazmi B
full_name: Budanur, Nazmi B
id: 3EA1010E-F248-11E8-B48F-1D18A9856A87
last_name: Budanur
orcid: 0000-0003-0423-5010
- first_name: Jan
full_name: Brugués, Jan
last_name: Brugués
- first_name: Martin
full_name: Loose, Martin
id: 462D4284-F248-11E8-B48F-1D18A9856A87
last_name: Loose
orcid: 0000-0001-7309-9724
citation:
ama: Dos Santos Caldas PR, Lopez Pelegrin MD, Pearce DJG, Budanur NB, Brugués J,
Loose M. Cooperative ordering of treadmilling filaments in cytoskeletal networks
of FtsZ and its crosslinker ZapA. Nature Communications. 2019;10. doi:10.1038/s41467-019-13702-4
apa: Dos Santos Caldas, P. R., Lopez Pelegrin, M. D., Pearce, D. J. G., Budanur,
N. B., Brugués, J., & Loose, M. (2019). Cooperative ordering of treadmilling
filaments in cytoskeletal networks of FtsZ and its crosslinker ZapA. Nature
Communications. Springer Nature. https://doi.org/10.1038/s41467-019-13702-4
chicago: Dos Santos Caldas, Paulo R, Maria D Lopez Pelegrin, Daniel J. G. Pearce,
Nazmi B Budanur, Jan Brugués, and Martin Loose. “Cooperative Ordering of Treadmilling
Filaments in Cytoskeletal Networks of FtsZ and Its Crosslinker ZapA.” Nature
Communications. Springer Nature, 2019. https://doi.org/10.1038/s41467-019-13702-4.
ieee: P. R. Dos Santos Caldas, M. D. Lopez Pelegrin, D. J. G. Pearce, N. B. Budanur,
J. Brugués, and M. Loose, “Cooperative ordering of treadmilling filaments in cytoskeletal
networks of FtsZ and its crosslinker ZapA,” Nature Communications, vol.
10. Springer Nature, 2019.
ista: Dos Santos Caldas PR, Lopez Pelegrin MD, Pearce DJG, Budanur NB, Brugués J,
Loose M. 2019. Cooperative ordering of treadmilling filaments in cytoskeletal
networks of FtsZ and its crosslinker ZapA. Nature Communications. 10, 5744.
mla: Dos Santos Caldas, Paulo R., et al. “Cooperative Ordering of Treadmilling Filaments
in Cytoskeletal Networks of FtsZ and Its Crosslinker ZapA.” Nature Communications,
vol. 10, 5744, Springer Nature, 2019, doi:10.1038/s41467-019-13702-4.
short: P.R. Dos Santos Caldas, M.D. Lopez Pelegrin, D.J.G. Pearce, N.B. Budanur,
J. Brugués, M. Loose, Nature Communications 10 (2019).
date_created: 2019-12-20T12:22:57Z
date_published: 2019-12-17T00:00:00Z
date_updated: 2023-09-07T13:18:51Z
day: '17'
ddc:
- '570'
department:
- _id: MaLo
- _id: BjHo
doi: 10.1038/s41467-019-13702-4
ec_funded: 1
external_id:
isi:
- '000503009300001'
file:
- access_level: open_access
checksum: a1b44b427ba341383197790d0e8789fa
content_type: application/pdf
creator: dernst
date_created: 2019-12-23T07:34:56Z
date_updated: 2020-07-14T12:47:53Z
file_id: '7208'
file_name: 2019_NatureComm_Caldas.pdf
file_size: 8488733
relation: main_file
file_date_updated: 2020-07-14T12:47:53Z
has_accepted_license: '1'
intvolume: ' 10'
isi: 1
language:
- iso: eng
license: https://creativecommons.org/licenses/by/4.0/
month: '12'
oa: 1
oa_version: Published Version
project:
- _id: 2595697A-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '679239'
name: Self-Organization of the Bacterial Cell
- _id: 260D98C8-B435-11E9-9278-68D0E5697425
name: Reconstitution of Bacterial Cell Division Using Purified Components
publication: Nature Communications
publication_identifier:
issn:
- 2041-1723
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
related_material:
record:
- id: '8358'
relation: dissertation_contains
status: public
scopus_import: '1'
status: public
title: Cooperative ordering of treadmilling filaments in cytoskeletal networks of
FtsZ and its crosslinker ZapA
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 10
year: '2019'
...
---
_id: '6069'
abstract:
- lang: eng
text: Electron transport in two-dimensional conducting materials such as graphene,
with dominant electron–electron interaction, exhibits unusual vortex flow that
leads to a nonlocal current-field relation (negative resistance), distinct from
the classical Ohm’s law. The transport behavior of these materials is best described
by low Reynolds number hydrodynamics, where the constitutive pressure–speed relation
is Stoke’s law. Here we report evidence of such vortices observed in a viscous
flow of Newtonian fluid in a microfluidic device consisting of a rectangular cavity—analogous
to the electronic system. We extend our experimental observations to elliptic
cavities of different eccentricities, and validate them by numerically solving
bi-harmonic equation obtained for the viscous flow with no-slip boundary conditions.
We verify the existence of a predicted threshold at which vortices appear. Strikingly,
we find that a two-dimensional theoretical model captures the essential features
of three-dimensional Stokes flow in experiments.
article_number: '937'
article_processing_charge: No
author:
- first_name: Jonathan
full_name: Mayzel, Jonathan
last_name: Mayzel
- first_name: Victor
full_name: Steinberg, Victor
last_name: Steinberg
- first_name: Atul
full_name: Varshney, Atul
id: 2A2006B2-F248-11E8-B48F-1D18A9856A87
last_name: Varshney
orcid: 0000-0002-3072-5999
citation:
ama: Mayzel J, Steinberg V, Varshney A. Stokes flow analogous to viscous electron
current in graphene. Nature Communications. 2019;10. doi:10.1038/s41467-019-08916-5
apa: Mayzel, J., Steinberg, V., & Varshney, A. (2019). Stokes flow analogous
to viscous electron current in graphene. Nature Communications. Springer
Nature. https://doi.org/10.1038/s41467-019-08916-5
chicago: Mayzel, Jonathan, Victor Steinberg, and Atul Varshney. “Stokes Flow Analogous
to Viscous Electron Current in Graphene.” Nature Communications. Springer
Nature, 2019. https://doi.org/10.1038/s41467-019-08916-5.
ieee: J. Mayzel, V. Steinberg, and A. Varshney, “Stokes flow analogous to viscous
electron current in graphene,” Nature Communications, vol. 10. Springer
Nature, 2019.
ista: Mayzel J, Steinberg V, Varshney A. 2019. Stokes flow analogous to viscous
electron current in graphene. Nature Communications. 10, 937.
mla: Mayzel, Jonathan, et al. “Stokes Flow Analogous to Viscous Electron Current
in Graphene.” Nature Communications, vol. 10, 937, Springer Nature, 2019,
doi:10.1038/s41467-019-08916-5.
short: J. Mayzel, V. Steinberg, A. Varshney, Nature Communications 10 (2019).
date_created: 2019-03-05T13:18:30Z
date_published: 2019-02-26T00:00:00Z
date_updated: 2023-09-08T11:39:02Z
day: '26'
ddc:
- '530'
- '532'
department:
- _id: BjHo
doi: 10.1038/s41467-019-08916-5
ec_funded: 1
external_id:
isi:
- '000459704600001'
file:
- access_level: open_access
checksum: 61192fc49e0d44907c2a4fe384e4b97f
content_type: application/pdf
creator: dernst
date_created: 2019-03-05T13:33:04Z
date_updated: 2020-07-14T12:47:18Z
file_id: '6070'
file_name: 2019_NatureComm_Mayzel.pdf
file_size: 2646391
relation: main_file
file_date_updated: 2020-07-14T12:47:18Z
has_accepted_license: '1'
intvolume: ' 10'
isi: 1
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
project:
- _id: 260C2330-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '754411'
name: ISTplus - Postdoctoral Fellowships
publication: Nature Communications
publication_identifier:
issn:
- 2041-1723
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Stokes flow analogous to viscous electron current in graphene
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 10
year: '2019'
...
---
_id: '6014'
abstract:
- lang: eng
text: Speed of sound waves in gases and liquids are governed by the compressibility
of the medium. There exists another type of non-dispersive wave where the wave
speed depends on stress instead of elasticity of the medium. A well-known example
is the Alfven wave, which propagates through plasma permeated by a magnetic field
with the speed determined by magnetic tension. An elastic analogue of Alfven waves
has been predicted in a flow of dilute polymer solution where the elastic stress
of the stretching polymers determines the elastic wave speed. Here we present
quantitative evidence of elastic Alfven waves in elastic turbulence of a viscoelastic
creeping flow between two obstacles in channel flow. The key finding in the experimental
proof is a nonlinear dependence of the elastic wave speed cel on the Weissenberg
number Wi, which deviates from predictions based on a model of linear polymer
elasticity.
article_number: '652'
article_processing_charge: No
article_type: original
author:
- first_name: Atul
full_name: Varshney, Atul
id: 2A2006B2-F248-11E8-B48F-1D18A9856A87
last_name: Varshney
orcid: 0000-0002-3072-5999
- first_name: Victor
full_name: Steinberg, Victor
last_name: Steinberg
citation:
ama: Varshney A, Steinberg V. Elastic alfven waves in elastic turbulence. Nature
Communications. 2019;10. doi:10.1038/s41467-019-08551-0
apa: Varshney, A., & Steinberg, V. (2019). Elastic alfven waves in elastic turbulence.
Nature Communications. Springer Nature. https://doi.org/10.1038/s41467-019-08551-0
chicago: Varshney, Atul, and Victor Steinberg. “Elastic Alfven Waves in Elastic
Turbulence.” Nature Communications. Springer Nature, 2019. https://doi.org/10.1038/s41467-019-08551-0.
ieee: A. Varshney and V. Steinberg, “Elastic alfven waves in elastic turbulence,”
Nature Communications, vol. 10. Springer Nature, 2019.
ista: Varshney A, Steinberg V. 2019. Elastic alfven waves in elastic turbulence.
Nature Communications. 10, 652.
mla: Varshney, Atul, and Victor Steinberg. “Elastic Alfven Waves in Elastic Turbulence.”
Nature Communications, vol. 10, 652, Springer Nature, 2019, doi:10.1038/s41467-019-08551-0.
short: A. Varshney, V. Steinberg, Nature Communications 10 (2019).
date_created: 2019-02-15T07:10:46Z
date_published: 2019-02-08T00:00:00Z
date_updated: 2023-09-08T11:39:54Z
day: '08'
ddc:
- '530'
department:
- _id: BjHo
doi: 10.1038/s41467-019-08551-0
ec_funded: 1
external_id:
arxiv:
- '1902.03763'
isi:
- '000458175300001'
file:
- access_level: open_access
checksum: d3acf07eaad95ec040d8e8565fc9ac37
content_type: application/pdf
creator: dernst
date_created: 2019-02-15T07:15:00Z
date_updated: 2020-07-14T12:47:17Z
file_id: '6015'
file_name: 2019_NatureComm_Varshney.pdf
file_size: 1331490
relation: main_file
file_date_updated: 2020-07-14T12:47:17Z
has_accepted_license: '1'
intvolume: ' 10'
isi: 1
language:
- iso: eng
month: '02'
oa: 1
oa_version: Published Version
project:
- _id: 260C2330-B435-11E9-9278-68D0E5697425
call_identifier: H2020
grant_number: '754411'
name: ISTplus - Postdoctoral Fellowships
publication: Nature Communications
publication_identifier:
issn:
- 2041-1723
publication_status: published
publisher: Springer Nature
quality_controlled: '1'
scopus_import: '1'
status: public
title: Elastic alfven waves in elastic turbulence
tmp:
image: /images/cc_by.png
legal_code_url: https://creativecommons.org/licenses/by/4.0/legalcode
name: Creative Commons Attribution 4.0 International Public License (CC-BY 4.0)
short: CC BY (4.0)
type: journal_article
user_id: c635000d-4b10-11ee-a964-aac5a93f6ac1
volume: 10
year: '2019'
...
---
_id: '6779'
abstract:
- lang: eng
text: "Recent studies suggest that unstable recurrent solutions of the Navier-Stokes
equation provide new insights\r\ninto dynamics of turbulent flows. In this study,
we compute an extensive network of dynamical connections\r\nbetween such solutions
in a weakly turbulent quasi-two-dimensional Kolmogorov flow that lies in the inversion
symmetric subspace. In particular, we find numerous isolated heteroclinic connections
between different\r\ntypes of solutions—equilibria, periodic, and quasiperiodic
orbits—as well as continua of connections forming\r\nhigher-dimensional connecting
manifolds. We also compute a homoclinic connection of a periodic orbit and\r\nprovide
strong evidence that the associated homoclinic tangle forms the chaotic repeller
that underpins transient\r\nturbulence in the symmetric subspace."
article_number: '013112'
article_processing_charge: No
article_type: original
author:
- first_name: Balachandra
full_name: Suri, Balachandra
id: 47A5E706-F248-11E8-B48F-1D18A9856A87
last_name: Suri
- first_name: Ravi Kumar
full_name: Pallantla, Ravi Kumar
last_name: Pallantla
- first_name: Michael F.
full_name: Schatz, Michael F.
last_name: Schatz
- first_name: Roman O.
full_name: Grigoriev, Roman O.
last_name: Grigoriev
citation:
ama: Suri B, Pallantla RK, Schatz MF, Grigoriev RO. Heteroclinic and homoclinic
connections in a Kolmogorov-like flow. Physical Review E. 2019;100(1).
doi:10.1103/physreve.100.013112
apa: Suri, B., Pallantla, R. K., Schatz, M. F., & Grigoriev, R. O. (2019). Heteroclinic
and homoclinic connections in a Kolmogorov-like flow. Physical Review E.
American Physical Society. https://doi.org/10.1103/physreve.100.013112
chicago: Suri, Balachandra, Ravi Kumar Pallantla, Michael F. Schatz, and Roman O.
Grigoriev. “Heteroclinic and Homoclinic Connections in a Kolmogorov-like Flow.”
Physical Review E. American Physical Society, 2019. https://doi.org/10.1103/physreve.100.013112.
ieee: B. Suri, R. K. Pallantla, M. F. Schatz, and R. O. Grigoriev, “Heteroclinic
and homoclinic connections in a Kolmogorov-like flow,” Physical Review E,
vol. 100, no. 1. American Physical Society, 2019.
ista: Suri B, Pallantla RK, Schatz MF, Grigoriev RO. 2019. Heteroclinic and homoclinic
connections in a Kolmogorov-like flow. Physical Review E. 100(1), 013112.
mla: Suri, Balachandra, et al. “Heteroclinic and Homoclinic Connections in a Kolmogorov-like
Flow.” Physical Review E, vol. 100, no. 1, 013112, American Physical Society,
2019, doi:10.1103/physreve.100.013112.
short: B. Suri, R.K. Pallantla, M.F. Schatz, R.O. Grigoriev, Physical Review E 100
(2019).
date_created: 2019-08-09T09:40:41Z
date_published: 2019-07-25T00:00:00Z
date_updated: 2024-02-28T13:13:00Z
day: '25'
ddc:
- '532'
department:
- _id: BjHo
doi: 10.1103/physreve.100.013112
ec_funded: 1
external_id:
arxiv:
- '1907.05860'
isi:
- '000477911800012'
intvolume: ' 100'
isi: 1
issue: '1'
language:
- iso: eng
main_file_link:
- open_access: '1'
url: https://arxiv.org/abs/1907.05860
month: '07'
oa: 1
oa_version: Preprint
project:
- _id: 25681D80-B435-11E9-9278-68D0E5697425
call_identifier: FP7
grant_number: '291734'
name: International IST Postdoc Fellowship Programme
publication: Physical Review E
publication_identifier:
eissn:
- 2470-0053
issn:
- 2470-0045
publication_status: published
publisher: American Physical Society
quality_controlled: '1'
scopus_import: '1'
status: public
title: Heteroclinic and homoclinic connections in a Kolmogorov-like flow
type: journal_article
user_id: 2DF688A6-F248-11E8-B48F-1D18A9856A87
volume: 100
year: '2019'
...