TY  - JOUR
A1  - Götten, Falk
A1  - Havermann, Marc
A1  - Braun, Carsten
A1  - Marino, Matthew
A1  - Bil, Cees
T1  - Wind-tunnel and CFD investigations of UAV landing gears and turrets – Improvements in empirical drag estimation
JF  - Aerospace Science and Technology
N2  - This paper analyzes the drag characteristics of several landing gear and turret configurations that are representative of unmanned aircraft tricycle landing gears and sensor turrets. A variety of these components were constructed via 3D-printing and analyzed in a wind-tunnel measurement campaign. Both turrets and landing gears were attached to a modular fuselage that supported both isolated components and multiple components at a time. Selected cases were numerically investigated with a Reynolds-averaged Navier-Stokes approach that showed good accuracy when compared to wind-tunnel data. The drag of main gear struts could be significantly reduced via streamlining their cross-sectional shape and keeping load carrying capabilities similar. The attachment of wheels introduced interference effects that increased strut drag moderately but significantly increased wheel drag compared to isolated cases. Very similar behavior was identified for front landing gears. The drag of an electro-optical and infrared sensor turret was found to be much higher than compared to available data of a clean hemisphere-cylinder combination. This turret drag was merely influenced by geometrical features like sensor surfaces and the rotational mechanism. The new data of this study is used to develop simple drag estimation recommendations for main and front landing gear struts and wheels as well as sensor turrets. These recommendations take geometrical considerations and interference effects into account.
Y1  - 2020
U6  - https://doi.org/10.1016/j.ast.2020.106306
SN  - 1270-9638
VL  - 107
IS  - Art. 106306
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Hailer, Benjamin
A1  - Weber, Tobias
A1  - Neveling, Sebastian
A1  - Dera, Samuel
A1  - Arent, Jan-Christoph
A1  - Middendorf, Peter
T1  - Development of a test device to determine the frictional behavior between honeycomb and prepreg layers under realistic manufacturing conditions
JF  - Journal of Sandwich Structures & Materials
N2  - In the friction tests between honeycomb with film adhesive and prepreg, the relative displacement occurs between the film adhesive and the prepreg. The film adhesive does not shift relative to the honeycomb. This is consistent with the core crush behavior where the honeycomb moves together with the film adhesive, as can be seen in Figure 2(a). The pull-through forces of the friction measurements between honeycomb and prepreg at 1 mm deformation are plotted in Figure 17(a). While the friction at 100°C is similar to the friction at 120°C, it decreases significantly at 130°C and exhibits a minimum at 140°C. At 150°C, the friction rises again slightly and then sharply at 160°C. Since the viscosity of the M18/1 prepreg resin drops significantly before it cures [23], the minimum friction at 140°C could result from a minimum viscosity of the mixture of prepreg resin and film adhesive before the bond subsequently cures. Figure 17(b) shows the mean value curve of the friction measurements at 140°C. The error bars, which represent the standard deviation, reveal the good repeatability of the tests. The force curve is approximately horizontal between 1 mm and 2 mm. The friction then slightly rises. As with interlaminar friction measurements, this could be due to the fact that resin is removed by friction and the proportion of boundary lubrication increases. Figure 18 shows the surfaces after the friction measurement. The honeycomb cell walls are clearly visible in the film adhesive. There are areas where the film adhesive is completely removed and the carrier material of the film adhesive becomes visible. In addition, the viscosity of the resin changes as the curing progresses during the friction test. This can also affect the force-displacement curve.
Y1  - 2020
U6  - https://doi.org/10.1177/1099636220923986
SN  - 1530-7972
IS  - Volume 23, Issue 7
SP  - 3017
EP  - 3043
PB  - Sage
CY  - London
ER  - 
TY  - JOUR
A1  - Haj Ayed, A.
A1  - Kusterer, K.
A1  - Funke, Harald
A1  - Keinz, Jan
A1  - Striegan, Constantin
A1  - Bohn, D.
T1  - Experimental and numerical investigations of the dry-low-NOx hydrogen micromix combustion chamber of an industrial gas turbine
JF  - Propulsion and power research
Y1  - 2015
U6  - https://doi.org/10.1016/j.jppr.2015.07.005
SN  - 2212-540X
VL  - Vol. 4
IS  - Iss. 3
SP  - 123
EP  - 131
ER  - 
TY  - JOUR
A1  - Haj Ayed, A.
A1  - Kusterer, K.
A1  - Funke, Harald
A1  - Keinz, Jan
A1  - Striegan, Constantin
A1  - Bohn, D.
T1  - Improvement study for the dry-low-NOx hydrogen micromix combustion technology
JF  - Propulsion and power research
Y1  - 2015
U6  - https://doi.org/10.1016/j.jppr.2015.07.003
SN  - 2212-540X
VL  - Vol. 4
IS  - Iss. 3
SP  - 132
EP  - 140
ER  - 
TY  - JOUR
A1  - Hammer, Thorben
A1  - Quitter, Julius
A1  - Mayntz, Joscha
A1  - Bauschat, J.-Michael
A1  - Dahmann, Peter
A1  - Götten, Falk
A1  - Hille, Sebastian
A1  - Stumpf, Eike
T1  - Free fall drag estimation of small-scale multirotor unmanned aircraft systems using computational fluid dynamics and wind tunnel experiments
JF  - CEAS Aeronautical Journal
N2  - New European Union (EU) regulations for UAS operations require an operational risk analysis, which includes an estimation of the potential danger of the UAS crashing. A key parameter for the potential ground risk is the kinetic impact energy of the UAS. The kinetic energy depends on the impact velocity of the UAS and, therefore, on the aerodynamic drag and the weight during free fall. Hence, estimating the impact energy of a UAS requires an accurate drag estimation of the UAS in that state. The paper at hand presents the aerodynamic drag estimation of small-scale multirotor UAS. Multirotor UAS of various sizes and configurations were analysed with a fully unsteady Reynolds-averaged Navier–Stokes approach. These simulations included different velocities and various fuselage pitch angles of the UAS. The results were compared against force measurements performed in a subsonic wind tunnel and provided good consistency. Furthermore, the influence of the UAS`s fuselage pitch angle as well as the influence of fixed and free spinning propellers on the aerodynamic drag was analysed. Free spinning propellers may increase the drag by up to 110%, depending on the fuselage pitch angle. Increasing the fuselage pitch angle of the UAS lowers the drag by 40% up to 85%, depending on the UAS. The data presented in this paper allow for increased accuracy of ground risk assessments.
KW  - Multirotor UAS
KW  - Drag estimation
KW  - CFD
KW  - Wind tunnel experiments
KW  - Wind milling
Y1  - 2023
U6  - https://doi.org/10.1007/s13272-023-00702-w
SN  - 1869-5590 (Online)
SN  - 1869-5582 (Print)
N1  - Corresponding author: Thorben Hammer
PB  - Springer
CY  - Wien
ER  - 
TY  - JOUR
A1  - Harder, Jörn
T1  - A crystallographic model for the study of local deformation processes in polycrystals
JF  - International journal of plasticity. 15 (1999), H. 6
Y1  - 1999
SN  - 0749-6419
N1  - Online: http://opus.tu-bs.de/opus/volltexte/1999/10/pdf/10_1.pdf
SP  - 605
EP  - 624
ER  - 
TY  - JOUR
A1  - Havermann, Marc
T1  - Systematic Shock Tube Experiments on Vortex Ring Generation and Propagation / Havermann, M. ; Kainuma, M. ; Takayama, K.
JF  - Shock waves : proceedings of the 25th International Symposium on Shock Waves-ISSW25, July 17 - 22, 2005, Bangalore, India / ed.: G. Jagadeesh
Y1  - 2006
SN  - 978-81-7371571-6
N1  - International Symposium on Shock Waves ; 25 (Bangalore) : 2005.07.17-22
ISSW ; 25 (Bangalore) : 2005.07.17-22
PB  - Universities Pr.
CY  - Hyderabad
ER  - 
TY  - JOUR
A1  - Havermann, Marc
T1  - Effects of the shock tube open-end shape on vortex loops released from it / Kainuma, M. ; Havermann, M. ; Sun, M. ; Takayama, K.
JF  - Shock Waves : Proceedings of the 24th International Symposium on Shock Waves Beijing, China July 11-16, 2004 / edited by Z. Jiang
Y1  - 2005
SN  - 978-3-540-22497-6
SP  - 505
EP  - 510
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Beylich, A. E.
T1  - Performance and Limitations of the Laser-Induced Fluorescence Measurement Technique and the Established Experimental Methods for the Study of Supersonic Mixing / Havermann, M. ; Beylich, A. E.
JF  - International Journal of heat and technology. 15 (1997), H. 2
Y1  - 1997
SP  - 3
EP  - 10
PB  - -
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Beylich, A. E.
T1  - Combined Measurement of Velocity, Temperature and Pressure in Compressible Gas Flows Using Laser-Induced Iodine Fluorescence / Havermann, M. ; Beylich, A. E.
Y1  - 1998
N1  - 9th International Symposium on Applications of Laser Techniques to Fluid Mechanics, Lisbon (Portugal), 1998
PB  - -
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Ende, H.
A1  - Seiler, F.
A1  - Schwenzer, M.
T1  - Shock tunnel measurement of the interaction amplification factor for a hot gas side jet in a supersonic cross flow / Havermann, M. ; Ende, H. ; Seiler, F. ; Schwenzer, M.
JF  - Shock Waves : Proceedings of the 24th International Symposium on Shock Waves Beijing, China July 11-16, 2004 / edited by Z. Jiang
Y1  - 2005
SN  - 978-3-540-22497-6
SP  - 113
EP  - 118
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Haertig, J.
A1  - Rey, C.
A1  - George, A.
T1  - Particle image velocimetry in mach 3.5 and 4.5 shock-tunnel flows / Haertig, J. ; Havermann, M. ; Rey, C. ; George, A.
JF  - AIAA journal. 40 (2002), H. 6
Y1  - 2002
SN  - 0001-1452
N1  - Printausgabe in der Bereichsbibliothek Eupener Str. Signatur: 23 Z 701
SP  - 1056
EP  - 1060
PB  - -
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Haertig, J.
A1  - Rey, C.
A1  - George, A.
T1  - PIV Measurements in Shock Tunnels and Shock Tubes / Havermann, M. ; Haertig, J. ; Rey, C. ; George, A.
JF  - Particle Image Velocimetry : New Developments and Recent Applications
Y1  - 2008
SN  - 978-3-540-73528-1
N1  - Topics in applied physics. Vol 112.
SP  - 429
EP  - 442
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Haertig, J.
A1  - Rey, C.
A1  - George, F.
T1  - PIV measurements in Mach 3.5 and 4.5 shock tunnel flow / Haertig, J. ; Havermann, M. ; Rey, C. ; George, F.
Y1  - 2001
N1  - AIAA-2001-699 
Aerospace Sciences Meeting and Exhibit, 39th, Reno, NV, Jan. 8-11, 2001
PB  - -
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Kainuma, M.
A1  - Takayama, K.
T1  - Influence of Physical and Geometrical Parameters on Vortex Rings Generated by a Shock Tube / Havermann, M. ; Kainuma, M. ; Takayama, K.
JF  - Non-lethal options enhancing security and stability : 3rd European Symposium on Non-Lethal Weapons, May 10 - 12, 2005, Ettlingen, Germany / ICT, Fraunhofer-Institut Chemische Technologie; European Working Group Non-Lethal Weapons
Y1  - 2005
N1  - European Symposium on Non-Lethal Weapons ; (3 ; 2005.5.10-12 ; Ettlingen); V 24
PB  - ICT
CY  - Pfinztal
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Moeglin, J.-P.
T1  - ISL's Research on Systems with Controlled Effects for Non-Lethal Applications / Moeglin, J.-P. ; Havermann, M. et al.
JF  - Non-lethal options enhancing security and stability : 3rd European Symposium on Non-Lethal Weapons, May 10 - 12, 2005, Ettlingen, Germany / ICT, Fraunhofer-Institut Chemische Technologie; European Working Group Non-Lethal Weapons
Y1  - 2005
N1  - European Symposium on Non-Lethal Weapons ; (3 ; 2005.5.10-12 ; Ettlingen); P 35
PB  - ICT
CY  - Pfinztal
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Salve, M. de
A1  - Tin, G. del
A1  - Panella, B.
T1  - Experimental Study of the Temperature Field along a Density Lock / Salve, M. de ; Tin, G. del ; Panella, B. ; Sansoldo, D. ; Havermann, M.
JF  - Proceedings : International Conference on New Trends in Nuclear System Thermohydraulics, May 30th - June 2nd, 1994, Pisa / organized by Dipartimento di Costruzioni Meccaniche e Nucleari ... . Ed. by Francesco Oriolo
Y1  - 1994
N1  - International Conference on New Trends in Nuclear System Thermohydraulics ; (1994.05.30-06.02 ; Pisa)
SP  - 623
EP  - 630
PB  - -
CY  - Pisa
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Seiler, F.
T1  - Boundary Layer Influence on Supersonic Jet/Cross-Flow Interaction in Hypersonic Flow / Havermann, M. ; Seiler, F.
JF  - Notes on Numerical Fluid Mechanics and Multidisciplinary Design. 92 (2006)
Y1  - 2006
SN  - 1612-2909
N1  - New results in numerical and experimental fluid mechanics ; V ;
ISBN 978-3-540-33287-9
SP  - 281
EP  - 288
PB  - -
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Seiler, F.
A1  - Boller, F.
A1  - Mangold, P.
T1  - Operation of the ISL transonic shock tube in a high subsonic flow regime / Seiler, F. ; Havermann, M. ; Boller, F. ; Mangold, P. ; Takayama K.
JF  - Shock Waves : Proceedings of the 24th International Symposium on Shock Waves Beijing, China July 11-16, 2004 / edited by Z. Jiang
Y1  - 2005
SN  - 978-3-540-22497-6
SP  - 307
EP  - 312
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Havermann, Marc
A1  - Seiler, F.
A1  - George, A.
A1  - Leopold, F.
T1  - Planar Velocity Visualization in High-Speed Wedge Flow using Doppler Picture Velocimetry (DPV) compared with Particle Image Velocimetry (PIV) / Seiler, F. ; Havermann, M. ; George, A. ; Leopold, F. ; Srulijes, J.
JF  - Journal of Visualization. 6 (2003), H. 3
Y1  - 2003
SN  - 1343-8875
SP  - 253
EP  - 262
PB  - -
ER  -