Novara, Matteo and Schanz, Daniel and Geisler, Reinhard and Gesemann, Sebastian and Voss, Christina and Schröder, Andreas (2019) 3D Lagrangian Particle Tracking with Multi-Pulse Shake-The-Box in Turbulent Boundary Layer Flows at High Reynolds Numbers. In: 17th European Turbulence Conference ETC 2019 (227), 1 - 1. 17th European Turbulence Conference ETC 2019, 03. - 06. Sept. 2019, Torino, Italy.
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Abstract
The recent introduction of the Multi-Pulse Shake-The-Box technique (MP-STB [3]) extended the capabilities of the Shake-The-Box (STB [4]) 3D Lagrangian particle tracking (LPT) algorithm in terms of applicable flow velocity. In particular, the MP-STB allows for 3D LPT investigations at velocities relevant for industrial and aerodynamic applications in relatively large volumes where the adoption of a time-resolved recording strategy would result in significant compromises in terms of spatial range or resolution (in order to limit the particle displacement between subsequent recordings). Multi-pulse sequences are obtained by synchronizing multiple illumination systems to generate bursts of laser pulses (typically four) where the time separation can be freely adjusted down to less than a microsecond (e.g. for supersonic applications). A 3D imaging system consisting of dual-frame cameras is adopted, where each frame is double-exposed to record the four pulses [2]; the MP-STB technique makes use of an iterative approach to overcome the limitations posed by the short observation time offered by the multi-pulse recording sequence, and allows for the reconstruction of individual four-pulse particle tracks in 3D [3]. The acquisition of long sequences of four-pulse recordings at low frequency (10-15Hz) enables the evaluation of flow statistics. In the present study, the MP-STB technique is employed for the investigation of turbulent boundary layer (TBL) flows at relatively high Reynolds numbers. A TBL at 15 m/s (Reθ ≈ 10; 000) is investigated in the SWG facility at DLR Göttingen; approximately 95; 000 individual tracks are reconstructed within the 80×120×10 mm^3 domain for each four-pulse recording. Spatial gradients, as well as the instantaneous 3D pressure field, are evaluated by means of the FlowFit data assimilation algorithm [1] (fig.1-left). A TBL with adverse pressure gradient (APG) at 29 m/s (Reθ ≈ 30; 000) is investigated in the atmospheric wind tunnel of the University of Armed Forces in Munich; both planar PIV and MP-STB in a 80 × 90 × 7 mm^3 domain are employed; the direct comparison of the results in terms of turbulent fluctuations (fig.1-right) highlights the higher spatial resolution of the LPT approach which, unlike PIV, does not suffer from the signal modulation caused by the finite size of the cross-correlation window. In the final presentation the MP-STB processing technique will be introduced together with the main parameters affecting its performances. Moreover, results regarding the TBL structure and flow statistics (e.g. TBL profiles, two-point correlations) will be presented.
Item URL in elib: | https://elib.dlr.de/129532/ | |||||||||||||||||||||
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Document Type: | Conference or Workshop Item (Speech) | |||||||||||||||||||||
Additional Information: | NUMERICAL METHODS AND DATA ANALYSIS• Session 5 | |||||||||||||||||||||
Title: | 3D Lagrangian Particle Tracking with Multi-Pulse Shake-The-Box in Turbulent Boundary Layer Flows at High Reynolds Numbers | |||||||||||||||||||||
Authors: |
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Date: | September 2019 | |||||||||||||||||||||
Journal or Publication Title: | 17th European Turbulence Conference ETC 2019 | |||||||||||||||||||||
Refereed publication: | Yes | |||||||||||||||||||||
Open Access: | Yes | |||||||||||||||||||||
Gold Open Access: | No | |||||||||||||||||||||
In SCOPUS: | No | |||||||||||||||||||||
In ISI Web of Science: | No | |||||||||||||||||||||
Page Range: | 1 - 1 | |||||||||||||||||||||
Editors: |
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Series Name: | Conference Proceedings online | |||||||||||||||||||||
Status: | Published | |||||||||||||||||||||
Keywords: | Lagrangian, 3D particle tracking, multi-pulse, Shake-The-Box, boundary layers | |||||||||||||||||||||
Event Title: | 17th European Turbulence Conference ETC 2019 | |||||||||||||||||||||
Event Location: | Torino, Italy | |||||||||||||||||||||
Event Type: | international Conference | |||||||||||||||||||||
Event Dates: | 03. - 06. Sept. 2019 | |||||||||||||||||||||
Organizer: | Università degli studi di Torino, Politecnico di Torino | |||||||||||||||||||||
Institution: | Deutsches Zentrum für Luft- und Raumfahrt e.V. | |||||||||||||||||||||
Department: | AS-EXV | |||||||||||||||||||||
HGF - Research field: | Aeronautics, Space and Transport | |||||||||||||||||||||
HGF - Program: | Aeronautics | |||||||||||||||||||||
HGF - Program Themes: | fixed-wing aircraft | |||||||||||||||||||||
DLR - Research area: | Aeronautics | |||||||||||||||||||||
DLR - Program: | L AR - Aircraft Research | |||||||||||||||||||||
DLR - Research theme (Project): | L - Simulation and Validation | |||||||||||||||||||||
Location: | Göttingen | |||||||||||||||||||||
Institutes and Institutions: | Institute for Aerodynamics and Flow Technology > Experimental Methods, GO Institute for Aerodynamics and Flow Technology > High Speed Configurations, GO | |||||||||||||||||||||
Deposited By: | Micknaus, Ilka | |||||||||||||||||||||
Deposited On: | 11 Oct 2019 17:05 | |||||||||||||||||||||
Last Modified: | 11 Oct 2019 17:05 |
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