TY  - CHAP
A1  - Götten, Falk
A1  - Havermann, Marc
A1  - Braun, Carsten
A1  - Gomez, Francisco
A1  - Bil, Cees
T1  - On the Applicability of Empirical Drag Estimation Methods for Unmanned Air Vehicle Design   Read More: https://arc.aiaa.org/doi/10.2514/6.2018-3192
T2  - 2018 Aviation Technology, Integration, and Operations Conference, AIAA AVIATION Forum
Y1  - 2018
U6  - http://dx.doi.org/10.2514/6.2018-3192
SN  - 1533-385X
N1  - AIAA 2018-3192
SP  - Article 3192
ER  - 
TY  - JOUR
A1  - Götten, Falk
A1  - Havermann, Marc
A1  - Braun, Carsten
A1  - Gomez, Francisco
A1  - Bil, Cees
T1  - RANS Simulation Validation of a Small Sensor Turret for UAVs
JF  - Journal of Aerospace Engineering
N2  - Recent Unmanned Aerial Vehicle (UAV) design procedures rely on full aircraft steady-state Reynolds-Averaged-Navier-Stokes (RANS) analyses in early design stages. Small sensor turrets are included in such simulations, even though their aerodynamic properties show highly unsteady behavior. Very little is known about the effects of this approach on the simulation outcomes of small turrets. Therefore, the flow around a model turret at a Reynolds number of 47,400 is simulated with a steady-state RANS approach and compared to experimental data. Lift, drag, and surface pressure show good agreement with the experiment. The RANS model predicts the separation location too far downstream and shows a larger recirculation region aft of the body. Both characteristic arch and horseshoe vortex structures are visualized and qualitatively match the ones found by the experiment. The Reynolds number dependence of the drag coefficient follows the trend of a sphere within a distinct range. The outcomes indicate that a steady-state RANS model of a small sensor turret is able to give results that are useful for UAV engineering purposes but might not be suited for detailed insight into flow properties.
Y1  - 2019
U6  - http://dx.doi.org/10.1061/(ASCE)AS.1943-5525.0001055
SN  - 1943-5525
VL  - 32
IS  - 5
PB  - ASCE
CY  - New York
ER  - 
TY  - CHAP
A1  - Rings, René
A1  - Ludowicy, Jonas
A1  - Finger, Felix
A1  - Braun, Carsten
A1  - Bil, Cees
T1  - Sensitivity Analysis of General Aviation Aircraft with Parallel Hybrid-Electric Propulsion Systems
T2  - Asia Pacific International Symposium on Aerospace Technology. APISAT 2019
Y1  - 2019
ER  - 
TY  - CHAP
A1  - Finger, Felix
A1  - Braun, Carsten
A1  - Bil, Cees
T1  - The Impact of Electric Propulsion on the Performance of VTOL UAVs
T2  - Deutscher Luft- und Raumfahrtkongress 2017, DLRK , München
Y1  - 2017
ER  - 
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  - http://dx.doi.org/10.1016/j.ast.2020.106306
SN  - 1270-9638
VL  - 107
IS  - Art. 106306
PB  - Elsevier
CY  - Amsterdam
ER  -