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Lohle S.,University of Stuttgart | Bohrk H.,German Aerospace Center | Fuchs U.,Institute For Raumfahrtsysteme | Kraetzig B.,Institute For Raumfahrtsysteme | Weih H.,German Aerospace Center
18th AIAA/3AF International Space Planes and Hypersonic Systems and Technologies Conference 2012 | Year: 2012

The German Aerospace Center (DLR) has developed a ceramic fin experiment (FinEx) for the HIFiRE-5 flight in order to test the performance of new structures with sharp leading edges during flight. The analysis of the thermal performance of the fin has been foreseen to be conducted by in-depth mounted thermocouples protocolling temperatures during flight. In a cooperative attempt between DLR and the Institut für Raumfahrtsysteme (IRS) of the University of Stuttgart, the thermal behavior is studied. In this paper, an approach is presented to determine the heat flux distribution onto the surface of the three-dimensional geometry of the fin. Using the Non-Integer System Identification (NISI) method, heat flux onto different surface elements is derived from only three thermocouples mounted inside the fin. Moreover, to increase accuracy, an area-weighted inverse method is used. The principal proof of concept is given based on a finite element thermal analysis of a cube. Measurements with a backup fin are used to show the approach experimentally in a plasma wind tunnel. Finally, the in-flight data has been evaluated and heat flux onto the fins during flight is presented. It can be concluded that the method is strongly dependent on surface discretization. However, the qualitative distribution is accurately determined. This approach allows to improve heat flux measurements for sparsely equipped flight hardware. © 2012 by the authors. Published by the American Institute of Aeronautics and Astronautics, Inc. Source


Eichhorn C.,University of Stuttgart | Eichhorn C.,Institute For Raumfahrtsysteme | Lohle S.,University of Stuttgart | Lohle S.,Institute For Raumfahrtsysteme | And 6 more authors.
Journal of Propulsion and Power | Year: 2012

Two-photon absorption laser-induced fluorescence (TALIF) measurements of relative ground state densities of neutral xenon on the plume axis of the radio-frequency ion thruster RIT-10 are reported. A TALIF scheme involving excitation of the 6p[1/2] 0 was applied. TALIF signals have been analyzed both in the cold gas flow and during thruster operation. Results show the principle feasibility of the investigated TALIF scheme, which seems to be a useful extension to formerly applied TALIF transitions for diagnostics in a thin xenon plasma. Copyright © 2012 by C. Eichhorn, S. Löhle, S. Fasoulas, H. Leiter, S. Fritzsche, and M. Auweter-Kurtz. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission. Source


Bauder U.,Institute For Raumfahrtsysteme | Majid A.,Institute For Raumfahrtsysteme | Fertig M.,German Aerospace Center | Auweter-Kurtz M.,Steinbeis Transferzentrum Plasma und Raumfahrttechnologie
10th AIAA/ASME Joint Thermophysics and Heat Transfer Conference | Year: 2010

The Finite-Volume Navier-Stokes code SINA was originally developed for the numerical simulation of re-entry problems and plasma wind tunnels. Therefore, the chemistry was fixed to Parks model for N2O2. In order to expand the operation purpose to hydrogen driven electric plasma sources or Martian atmosphere entry simulation for example, the chemistry part of the loosely coupled scheme is rebuilt more flexible using external files for the definition of the reaction scheme. A reaction scheme for hydrogen is implemented and the results are shown. The chemistry is solved using a Newton-method with numerical derivation and an Euler timestep for stability. © 2010 by the authors. Source


Herrmann S.,University of Bremen | Goklu E.,University of Bremen | Muntinga H.,University of Bremen | Resch A.,University of Bremen | And 3 more authors.
Microgravity Science and Technology | Year: 2010

The realization of a Bose Einstein condensate in the Bremen drop tower as achieved by the QUANTUS collaboration in 2007 has added a new field to microgravity research: the study of freely evolving degenerate quantum gases at largely extended evolution times. Here we give an outlook on some experiments that could be done with such ultra-cold quantum gases in this unique laboratory and on other microgravity platforms to study fundamental physics questions. In particular we consider experiments that could employ the increased precision of matter wave interferometers in microgravity to search for low-energy phenomena of quantum gravity. © 2010 Springer Science+Business Media B.V. Source


Lohle S.,Institute For Raumfahrtsysteme | Mezger A.,Kayser Threde GmbH | Fulge H.,Institute For Raumfahrtsysteme
Acta Astronautica | Year: 2013

The Hayabusa sample return capsule, which contained asteroid samples, re-entered the Earth's atmosphere on June 13, 2010. An ablative carbon-phenolic thermal protection system (TPS) was used to enable a safe return for the small capsule and the containing samples. Besides a research aircraft operated by NASA with a wide range of imaging and spectrographic cameras for remote sensing of the radiation of the Hayabusa capsule during its entry flight, observation from ground based stations has been realized. We participated in the ground based observation campaign with two instruments for spectroscopic and photometric measurements aiming to detect the surface temperature and the plasma radiation in front of the re-entering capsule. The system consists in an infrared camera and a wide range miniature fibre spectrometer. The paper presents the setup, the laboratory calibration procedure, and correction for transmission. The surface temperature of the capsule reached a peak of 3250 K when the capsule was at an altitude of 55.95 km. The thermographic camera measures independently slightly higher temperature at peak heating (3308 K). © 2012 Elsevier Ltd. All rights reserved. Source

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