elib
DLR-Header
DLR-Logo -> http://www.dlr.de
DLR Portal Home | Imprint | Privacy Policy | Contact | Deutsch
Fontsize: [-] Text [+]

Time-resolved Large-scale Volumetric Flow Measurement of a Helicopter Model Using Helium-filled Soap Bubbles

Michaelis, Dirk and Schwarz, Clemens and Bosbach, Johannes and Dierksheide, Uwe and Lemke, Christian and Wolf, C. Christian and Schanz, Daniel and Schröder, Andreas (2018) Time-resolved Large-scale Volumetric Flow Measurement of a Helicopter Model Using Helium-filled Soap Bubbles. In: 71st Annual Meeting of the APS Division of Fluid Dynamics. 71st Annual Meeting of the APS Division of Fluid Dynamics 2018, 18.-20. Nov. 2018, Atlanta, Georgia, USA.

Full text not available from this repository.

Official URL: http://meetings.aps.org/Meeting/DFD18/Session/D14.8

Abstract

This study describes time-resolved large-scale volumetric flow measurement of a helicopter model (1.55 m rotor-span, cord length = 61 mm) in close-to-ground condition (height = 0.5 D) at Reynolds number 4.1 x 10^5 (rotational frequency = 20.83 Hz) to examine CFD predicted secondary vortex structures (originating from primary rotor-tip vortices), as well as ground effects. Five high-repetition-rate cameras are used to image tracer particles (Helium-filled soap bubbles HFSB) in a 400 x 600 x 400 mm³ measurement volume at 1.7 kHz recording rate. HFSB tracer particles are illuminated by an array of over-pulsed high-power LED's. 50 sequences, with 3800 images each, at different angles of attack and different particle densities are recorded. The images are analysed using Shake-the-Box (time resolved particle tracking) to gather dense Lagrangian particle tracks. Further, data assimilation techniques (Flow Fit, Vortex-In-Cell VIC#) are applied for high-resolution grid-reconstruction of velocity, vorticity, acceleration and pressure (pressure from PTV) from the track data. First analysis confirms the presence of secondary vortex structures and reveals spanwise oriented vortex tubes close to the ground. Low pressure and high acceleration (150 g) are measured in the primary tip vortices.

Item URL in elib:https://elib.dlr.de/126221/
Document Type:Conference or Workshop Item (Speech)
Title:Time-resolved Large-scale Volumetric Flow Measurement of a Helicopter Model Using Helium-filled Soap Bubbles
Authors:
AuthorsInstitution or Email of AuthorsAuthors ORCID iD
Michaelis, DirkLaVision, GöttingenUNSPECIFIED
Schwarz, ClemensClemens.Schwarz (at) dlr.deUNSPECIFIED
Bosbach, JohannesJohannes.Bosbach (at) dlr.dehttps://orcid.org/0000-0002-1531-127X
Dierksheide, UweLaVision, GöttingenUNSPECIFIED
Lemke, ChristianLaVision, GöttingenUNSPECIFIED
Wolf, C. ChristianChristian.Wolf (at) dlr.dehttps://orcid.org/0000-0002-9052-7548
Schanz, Danieldaniel.schanz (at) dlr.deUNSPECIFIED
Schröder, Andreasandreas.schroeder (at) dlr.dehttps://orcid.org/0000-0002-6971-9262
Date:November 2018
Journal or Publication Title:71st Annual Meeting of the APS Division of Fluid Dynamics
Refereed publication:Yes
Open Access:No
Gold Open Access:No
In SCOPUS:No
In ISI Web of Science:No
Status:Published
Keywords:rotor wake, volumetric flow measurements, blade tip vortices, shake-the-box, soap bubbles
Event Title:71st Annual Meeting of the APS Division of Fluid Dynamics 2018
Event Location:Atlanta, Georgia, USA
Event Type:international Conference
Event Dates:18.-20. Nov. 2018
Organizer:American Physical Society APS
HGF - Research field:Aeronautics, Space and Transport
HGF - Program:Aeronautics
HGF - Program Themes:rotorcraft
DLR - Research area:Aeronautics
DLR - Program:L RR - Rotorcraft Research
DLR - Research theme (Project):L - The Virtual Aerodynamic Rotorcraft
Location: Göttingen
Institutes and Institutions:Institute for Aerodynamics and Flow Technology > Helicopter, GO
Institute for Aerodynamics and Flow Technology > Experimental Methods, GO
Deposited By: Winkels, Elisabeth
Deposited On:12 Feb 2019 03:33
Last Modified:12 Feb 2019 03:33

Repository Staff Only: item control page

Browse
Search
Help & Contact
Information
electronic library is running on EPrints 3.3.12
Copyright © 2008-2017 German Aerospace Center (DLR). All rights reserved.