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Application of Carbon Nanotubes and TemperatureSensitive Paint for the Detection of Boundary Layer Transition under Cryogenic Conditions

Klein, Christian and Henne, Ulrich and Yorita, Daisuke and Beifuss, Uwe and Ondrus, Vladimir and Hensch, Ann-Katrin and Longo, Roberto and Hauser, Michael and Guntermann, Peter and Quest, Jürgen (2017) Application of Carbon Nanotubes and TemperatureSensitive Paint for the Detection of Boundary Layer Transition under Cryogenic Conditions. AIAA-Tagung, SCITECH 2017, 09.-13, Jan. 2017, Gaylord Texan, Grapevine, Texas, USA.

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Official URL: https://scitech.aiaa.org/2017archives/


For aerodynamic profile tests on aircraft models, transition detection is of great interest. Under ambient flow conditions the infrared technique (IR) is a well-established image-based method for this purpose. In high Reynolds number tests which are conducted at cryogenic temperatures the IR technique is of only limited suitability. In contrast, the image-based Temperature-Sensitive Paint (TSP) technique is well-suited for these conditions. Boundary layer transition detection by means of TSP generally requires an artificial temperature difference between model surface and flow. For wind tunnels operated under cryogenic conditions this temperature difference can be generated by changing the liquid nitrogen injection rate of the working fluid causing a rapid change of the flow temperature. The drawback of this procedure is that du ring the change of the flow temperature neither the Reynolds nor the Mach number can be kept constant. To overcome this problem, we have recently published an alternative approach where Carbon Nanotubes (CNT) are used to electrically heat the model surface and thus generate a well-defined temperature difference to visualize laminar-turbulent transition. The combination of CNT and TSP, which we call cntTSP, delivered excellent results in different wind tunnel tests from ambient down to 150 K. At lower temperatures the previously used CNT layer failed to work, since the nanotubes were embedded into an acrylic binder material which is known to be unsuitable for cryogenic temperatures. In this paper we describe a new sensor development based on the idea that all paint components are mixed (CNT) or dissolved (TSP) in a polyurethane binder material, which has demonstrated its suitability for cryogenic testing in previous tests. After pre-testlng CNT and TSP in the laboratory, a cryogenic wind tunnel experiment was conducted in the pilot facility of the European Transonic Windtunnel (PETW) with the aim to visualize the laminar-turbulent transition on a twodimensional model for Reynolds number Re c S 10xl06• A comparison between the results of the standard temperature-step method of the working fluid and of the new approach based on the model surface heating by means of CNT will be presented and discussed.

Item URL in elib:https://elib.dlr.de/117594/
Document Type:Conference or Workshop Item (Speech)
Additional Information:551h AIAA Aerospace Sciences Meeting; DOI: 10.2514/6.2017-0336
Title:Application of Carbon Nanotubes and TemperatureSensitive Paint for the Detection of Boundary Layer Transition under Cryogenic Conditions
AuthorsInstitution or Email of AuthorsAuthor's ORCID iD
Klein, ChristianUNSPECIFIEDhttps://orcid.org/0000-0001-7592-6922
Beifuss, UweUni HohenheimUNSPECIFIED
Ondrus, VladimirUni HohenheimUNSPECIFIED
Hensch, Ann-KatrinEuropean Transonic Windtunnel (ETW), 51147 Cologne, GermanyUNSPECIFIED
Longo, RobertoEuropean Transonic Windtunnel (ETW), 51147 Cologne, GermanyUNSPECIFIED
Hauser, MichaelEuropean Transonic Windtunnel GmbH, Cologne 51147, GermanyUNSPECIFIED
Guntermann, PeterEuropean Transonic Windtunnel (ETW), 51147 Cologne, GermanyUNSPECIFIED
Quest, JürgenEuropean Transonic Windtunnel GmbH, Cologne 51147, GermanyUNSPECIFIED
Refereed publication:Yes
Open Access:Yes
Gold Open Access:No
In ISI Web of Science:No
Keywords:TSP, CNT, ETW, transition
Event Title:AIAA-Tagung, SCITECH 2017
Event Location:Gaylord Texan, Grapevine, Texas, USA
Event Type:international Conference
Event Dates:09.-13, Jan. 2017
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 (old)
Location: Göttingen
Institutes and Institutions:Institute for Aerodynamics and Flow Technology > Experimental Methods, GO
Deposited By: Bachmann, Barbara
Deposited On:31 Jan 2018 11:36
Last Modified:29 Mar 2023 00:07

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