TY - CHAP A1 - Pirovano, Laura A1 - Seefeldt, Patric A1 - Dachwald, Bernd A1 - Noomen, Ron T1 - Attitude and orbital modeling of an uncontrolled solar-sail experiment in low-Earth orbit T2 - 25th International Symposium on Space Flight Dynamics ISSFD N2 - Gossamer-1 is the first project of the three-step Gossamer roadmap, the purpose of which is to develop, prove and demonstrate that solar-sail technology is a safe and reliable propulsion technique for long-lasting and high-energy missions. This paper firstly presents the structural analysis performed on the sail to understand its elastic behavior. The results are then used in attitude and orbital simulations. The model considers the main forces and torques that a satellite experiences in low-Earth orbit coupled with the sail deformation. Doing the simulations for varying initial conditions in attitude and rotation rate, the results show initial states to avoid and maximum rotation rates reached for correct and faulty deployment of the sail. Lastly comparisons with the classic flat sail model are carried out to test the hypothesis that the elastic behavior does play a role in the attitude and orbital behavior of the sail KW - Solar sail KW - Gossamer structures KW - Attitude dynamics KW - Orbital dynamics Y1 - 2015 N1 - 25th International Symposium on Space Flight Dynamics ISSFD October 19 – 23, 2015, Munich, Germany https://issfd.org/2015/ SP - 1 EP - 15 ER - TY - CHAP A1 - Dachwald, Bernd A1 - Kahle, Ralph A1 - Wie, Bong T1 - Solar sail Kinetic Energy Impactor (KEI) mission design tradeoffs for impacting and deflecting asteroid 99942 Apophis T2 - AIAA/AAS Astrodynamics Specialist Conference and Exhibit N2 - Near-Earth asteroid 99942 Apophis provides a typical example for the evolution of asteroid orbits that lead to Earth-impacts after a close Earth-encounter that results in a resonant return. Apophis will have a close Earth-encounter in 2029 with potential very close subsequent Earth-encounters (or even an impact) in 2036 or later, depending on whether it passes through one of several so-called gravitational keyholes during its 2029-encounter. Several pre-2029-deflection scenarios to prevent Apophis from doing this have been investigated so far. Because the keyholes are less than 1 km in size, a pre-2029 kinetic impact is clearly the best option because it requires only a small change in Apophis' orbit to nudge it out of a keyhole. A single solar sail Kinetic Energy Impactor (KEI) spacecraft that impacts Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages at about 0.75 AU would be a feasible option to do this. The spacecraft consists of a 160 m x 160 m, 168 kg solar sail assembly and a 150 kg impactor. Although conventional spacecraft can also achieve the required minimum deflection of 1 km for this approx. 320 m-sized object from a prograde trajectory, our solar sail KEI concept also allows the deflection of larger objects. In this paper, we also show that, even after Apophis has flown through one of the gravitational keyholes in 2029, solar sail Kinetic Energy Impactor (KEI) spacecraft are still a feasible option to prevent Apophis from impacting the Earth, but many KEIs would be required for consecutive impacts to increase the total Earth-miss distance to a safe value. In this paper, we elaborate potential pre- and post-2029 KEI impact scenarios for a launch in 2020, and investigate tradeoffs between different mission parameters. KW - Solar Sail KW - Asteroid Deflection KW - Planetary Protection KW - Trajectory Optimization Y1 - 2006 U6 - http://dx.doi.org/10.2514/6.2006-6178 N1 - AIAA/AAS Astrodynamics Specialist Conference and Exhibit, 21 August 2006 - 24 August 2006, Keystone, Colorado(USA). SP - 1 EP - 20 ER - TY - CHAP A1 - Hallmann, Marcus A1 - Heidecker, Ansgar A1 - Schlotterer, Markus A1 - Dachwald, Bernd T1 - GTOC8: results and methods of team 15 DLR T2 - 26th AAS/AIAA Space Flight Mechanics Meeting, Napa, CA N2 - This paper describes the results and methods used during the 8th Global Trajectory Optimization Competition (GTOC) of the DLR team. Trajectory optimization is crucial for most of the space missions and usually can be formulated as a global optimization problem. A lot of research has been done to different type of mission problems. The most demanding ones are low thrust transfers with e.g. gravity assist sequences. In that case the optimal control problem is combined with an integer problem. In most of the GTOCs we apply a filtering of the problem based on domain knowledge. Y1 - 2016 N1 - 26th AAS/AIAA Space Flight Mechanics Meeting, February 14-18, 2016, Napa, California, U.S.A. Napa, CA ER - TY - CHAP A1 - Duprat, J. A1 - Dachwald, Bernd A1 - Hilchenbach, M. A1 - Engrand, Cecile A1 - Espe, C. A1 - Feldmann, M. A1 - Francke, G. A1 - Görög, Mark A1 - Lüsing, N. A1 - Langenhorst, Falko T1 - The MARVIN project: a micrometeorite harvester in Antarctic snow T2 - 44th Lunar and Planetary Science Conference N2 - MARVIN is an automated drilling and melting probe dedicated to collect pristine interplanetary dust particles (micrometeorites) from central Antarctica snow. Y1 - 2013 N1 - 44th Lunar and Planetary Science Conference, March 18-22, 2013, The Woodlands, Texas ER - TY - CHAP A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang A1 - Loeb, Horst W. A1 - Schartner, Karl-Heinz T1 - A comparison of SEP and NEP for a main belt asteroid sample return mission T2 - 7th International Symposium on Launcher Technologies, Barcelona, Spain, 02-05 April 2007 N2 - Innovative interplanetary deep space missions, like a main belt asteroid sample return mission, require ever larger velocity increments (∆V s) and thus ever more demanding propulsion capabilities. Providing much larger exhaust velocities than chemical high-thrust systems, electric low-thrust space-propulsion systems can significantly enhance or even enable such high-energy missions. In 1995, a European-Russian Joint Study Group (JSG) presented a study report on “Advanced Interplanetary Missions Using Nuclear-Electric Propulsion” (NEP). One of the investigated reference missions was a sample return (SR) from the main belt asteroid (19) Fortuna. The envisaged nuclear power plant, Topaz-25, however, could not be realized and also the worldwide developments in space reactor hardware stalled. In this paper, we investigate, whether such a mission is also feasible using a solar electric propulsion (SEP) system and compare our SEP results to corresponding NEP results. Y1 - 2007 SP - 1 EP - 10 ER - TY - CHAP A1 - Dachwald, Bernd T1 - Global optimization of low-thrust space missions using evolutionary neurocontrol T2 - Proceedings of the international workshop on global optimization N2 - Low-thrust space propulsion systems enable flexible high-energy deep space missions, but the design and optimization of the interplanetary transfer trajectory is usually difficult. It involves much experience and expert knowledge because the convergence behavior of traditional local trajectory optimization methods depends strongly on an adequate initial guess. Within this extended abstract, evolutionary neurocontrol, a method that fuses artificial neural networks and evolutionary algorithms, is proposed as a smart global method for low-thrust trajectory optimization. It does not require an initial guess. The implementation of evolutionary neurocontrol is detailed and its performance is shown for an exemplary mission. KW - Evolutionary Neurocontrol KW - Spacecraft Trajectory Optimization KW - Low-Thrust Propulsion Y1 - 2005 SP - 85 EP - 90 ER - TY - CHAP A1 - Dachwald, Bernd A1 - Baturkin, Volodymyr A1 - Coverstone, Victoria A1 - Diedrich, Ben A1 - Garbe, Gregory A1 - Görlich, Marianne A1 - Leipold, Manfred A1 - Lura, Franz A1 - Macdonald, Malcolm A1 - McInnes, Colin A1 - Mengali, Giovanni A1 - Quarta, Alessandro A1 - Rios-Reyes, Leonel A1 - Scheeres, Daniel J. A1 - Seboldt, Wolfgang A1 - Wie, Bong T1 - Potential effects of optical solar sail degredation on trajectory design T2 - AAS/AIAA Astrodynamics Specialist N2 - The optical properties of the thin metalized polymer films that are projected for solar sails are assumed to be affected by the erosive effects of the space environment. Their degradation behavior in the real space environment, however, is to a considerable degree indefinite, because initial ground test results are controversial and relevant inspace tests have not been made so far. The standard optical solar sail models that are currently used for trajectory design do not take optical degradation into account, hence its potential effects on trajectory design have not been investigated so far. Nevertheless, optical degradation is important for high-fidelity solar sail mission design, because it decreases both the magnitude of the solar radiation pressure force acting on the sail and also the sail control authority. Therefore, we propose a simple parametric optical solar sail degradation model that describes the variation of the sail film’s optical coefficients with time, depending on the sail film’s environmental history, i.e., the radiation dose. The primary intention of our model is not to describe the exact behavior of specific film-coating combinations in the real space environment, but to provide a more general parametric framework for describing the general optical degradation behavior of solar sails. Using our model, the effects of different optical degradation behaviors on trajectory design are investigated for various exemplary missions. Y1 - 2005 N1 - 2005 AAS/AIAA Astrodynamics Specialist Conference, 7-11.08.2005. Lake Tahoe, California https://www.space-flight.org/AAS_meetings/2005_astro/2005_astro.html SP - 1 EP - 23 ER - TY - CHAP A1 - Hille, Sebastian A1 - Stumpf, Eike A1 - Mayntz, Joscha A1 - Dahmann, Peter T1 - Prediction of sound exposure caused by a landing motor glider with recuperating propellers T2 - AIAA SCITECH 2023 Forum N2 - This paper presents an approach to predicting the sound exposure on the ground caused by a landing aircraft with recuperating propellers. The noise source along the trajectory of a flight specified for a steeper approach is simulated based on measurements of sound power levels and additional parameters of a single propeller placed in a wind tunnel. To validate the measured data/measurement results, these simulations are also supported by overflight measurements of a test aircraft. It is shown that the simple source models of propellers do not provide fully satisfactory results since the sound levels are estimated too low. Nevertheless, with a further reference comparison, margins for an acceptable increase in the sound power level of the aircraft on its now steeper approach path could be estimated. Thus, in this case, a +7 dB increase in SWL would not increase the SEL compared to the conventional approach within only 2 km ahead of the airfield. Y1 - 2023 U6 - http://dx.doi.org/10.2514/6.2023-0211 N1 - AIAA SCITECH 2023 Forum, 23-27 January 2023, National Harbor, MD & Online PB - AIAA ER - TY - CHAP A1 - Horikawa, Atsushi A1 - Ashikaga, Mitsugu A1 - Yamaguchi, Masato A1 - Ogino, Tomoyuki A1 - Aoki, Shigeki A1 - Wirsum, Manfred A1 - Funke, Harald A1 - Kusterer, Karsten T1 - Combined heat and power supply demonstration of Micro-Mix Hydrogen Combustion Applied to M1A-17 Gas Turbine T2 - Proceedings of ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition (GT2022) (Volume 3A) N2 - Kawasaki Heavy Industries, Ltd. (KHI), Aachen University of Applied Sciences, and B&B-AGEMA GmbH have investigated the potential of low NOx micro-mix (MMX) hydrogen combustion and its application to an industrial gas turbine combustor. Engine demonstration tests of a MMX combustor for the M1A-17 gas turbine with a co-generation system were conducted in the hydrogen-fueled power generation plant in Kobe City, Japan. This paper presents the results of the commissioning test and the combined heat and power (CHP) supply demonstration. In the commissioning test, grid interconnection, loading tests and load cut-off tests were successfully conducted. All measurement results satisfied the Japanese environmental regulation values. Dust and soot as well as SOx were not detected. The NOx emissions were below 84 ppmv at 15 % O2. The noise level at the site boundary was below 60 dB. The vibration at the site boundary was below 45 dB. During the combined heat and power supply demonstration, heat and power were supplied to neighboring public facilities with the MMX combustion technology and 100 % hydrogen fuel. The electric power output reached 1800 kW at which the NOx emissions were 72 ppmv at 15 % O2, and 60 %RH. Combustion instabilities were not observed. The gas turbine efficiency was improved by about 1 % compared to a non-premixed type combustor with water injection as NOx reduction method. During a total equivalent operation time of 1040 hours, all combustor parts, the M1A-17 gas turbine as such, and the co-generation system were without any issues. KW - industrial gas turbine KW - combustor development KW - fuels KW - hydrogen KW - emission Y1 - 2022 SN - 978-0-7918-8599-4 U6 - http://dx.doi.org/10.1115/GT2022-81620 N1 - ASME Turbo Expo 2022: Turbomachinery Technical Conference and Exposition June 13–17, 2022 Rotterdam, Netherlands PB - American Society of Mechanical Engineers CY - Fairfield ER - TY - CHAP A1 - Möhren, Felix A1 - Bergmann, Ole A1 - Janser, Frank A1 - Braun, Carsten T1 - On the determination of harmonic propeller loads T2 - AIAA SCITECH 2023 Forum N2 - Dynamic loads significantly impact the structural design of propeller blades due to fatigue and static strength. Since propellers are elastic structures, deformations and aerodynamic loads are coupled. In the past, propeller manufacturers established procedures to determine unsteady aerodynamic loads and the structural response with analytical steady-state calculations. According to the approach, aeroelastic coupling primarily consists of torsional deformations. They neglect bending deformations, deformation velocities, and inertia terms. This paper validates the assumptions above for a General Aviation propeller and a lift propeller for urban air mobility or large cargo drones. Fully coupled reduced-order simulations determine the dynamic loads in the time domain. A quasi-steady blade element momentum approach transfers loads to one-dimensional finite beam elements. The simulation results are in relatively good agreement with the analytical method for the General Aviation propeller but show increasing errors for the slender lift propeller. The analytical approach is modified to consider the induced velocities. Still, inertia and velocity proportional terms play a significant role for the lift propeller due to increased elasticity. The assumption that only torsional deformations significantly impact the dynamic loads of propellers is not valid. Adequate determination of dynamic loads of such designs requires coupled aeroelastic simulations or advanced analytical procedures. Y1 - 2023 U6 - http://dx.doi.org/10.2514/6.2023-2404 N1 - AIAA SCITECH 2023 Forum, 23-27 January 2023, National Harbor, MD & Online PB - AIAA ER - TY - CHAP A1 - Funke, Harald A1 - Beckmann, Nils A1 - Stefan, Lukas A1 - Keinz, Jan T1 - Hydrogen combustor integration study for a medium range aircraft engine using the dry-low NOx “Micromix” combustion principle T2 - Proceedings of the ASME Turbo Expo 2023: Turbomachinery Technical Conference and Exposition. Volume 1: Aircraft Engine. Boston, Massachusetts, USA. June 26–30, 2023 N2 - The feasibility study presents results of a hydrogen combustor integration for a Medium-Range aircraft engine using the Dry-Low-NOₓ Micromix combustion principle. Based on a simplified Airbus A320-type flight mission, a thermodynamic performance model of a kerosene and a hydrogen-powered V2530-A5 engine is used to derive the thermodynamic combustor boundary conditions. A new combustor design using the Dry-Low NOx Micromix principle is investigated by slice model CFD simulations of a single Micromix injector for design and off-design operation of the engine. Combustion characteristics show typical Micromix flame shapes and good combustion efficiencies for all flight mission operating points. Nitric oxide emissions are significant below ICAO CAEP/8 limits. For comparison of the Emission Index (EI) for NOₓ emissions between kerosene and hydrogen operation, an energy (kerosene) equivalent Emission Index is used. A full 15° sector model CFD simulation of the combustion chamber with multiple Micromix injectors including inflow homogenization and dilution and cooling air flows investigates the combustor integration effects, resulting NOₓ emission and radial temperature distributions at the combustor outlet. The results show that the integration of a Micromix hydrogen combustor in actual aircraft engines is feasible and offers, besides CO₂ free combustion, a significant reduction of NOₓ emissions compared to kerosene operation. KW - emission index KW - nitric oxides KW - aircraft engine KW - Micromix KW - combustion KW - hydrogen Y1 - 2023 SN - 978-0-7918-8693-9 U6 - http://dx.doi.org/10.1115/GT2023-102370 N1 - Paper No. GT2023-102370, V001T01A022 PB - ASME CY - New York ER - TY - CHAP A1 - Gehler, M. A1 - Ober-Blöbaum, S. A1 - Dachwald, Bernd T1 - Application of discrete mechanics and optimal control to spacecraft in non-keplerian motion around small solar system bodies T2 - Procceedings of the 60th International Astronautical Congress N2 - Prolonged operations close to small solar system bodies require a sophisticated control logic to minimize propellant mass and maximize operational efficiency. A control logic based on Discrete Mechanics and Optimal Control (DMOC) is proposed and applied to both conventionally propelled and solar sail spacecraft operating at an arbitrarily shaped asteroid in the class of Itokawa. As an example, stand-off inertial hovering is considered, recently identified as a challenging part of the Marco Polo mission. The approach is easily extended to stand-off orbits. We show that DMOC is applicable to spacecraft control at small objects, in particular with regard to the fact that the changes in gravity are exploited by the algorithm to optimally control the spacecraft position. Furthermore, we provide some remarks on promising developments. KW - Spacecraft Y1 - 2009 SN - 978-161567908-9 N1 - 60th International Astronautical Congress 2009, IAC 2009; Daejeon; South Korea; 12 October 2009 through 16 October 2009 SP - 1360 EP - 1371 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Dachwald, Bernd A1 - Wurm, P. T1 - Design concept and modeling of an advanced solar photon thruster T2 - Advances in the Astronautical Sciences N2 - The so-called "compound solar sail", also known as "Solar Photon Thruster" (SPT), holds the potential of providing significant performance advantages over the flat solar sail. Previous SPT design concepts, however, do not consider shadowing effects and multiple reflections of highly concentrated solar radiation that would inevitably destroy the gossamer sail film. In this paper, we propose a novel advanced SPT (ASPT) design concept that does not suffer from these oversimplifications. We present the equations that describe the thrust force acting on such a sail system and compare its performance with respect to the conventional flat solar sail. KW - solar sails Y1 - 2009 SN - 978-087703554-1 SN - 00653438 N1 - 19th AAS/AIAA Space Flight Mechanics Meeting; Savannah, GA; United States; 8 February 2009 through 12 February 2009 SP - 723 EP - 740 PB - American Astronautical Society CY - San Diego, Calif. ER - TY - CHAP A1 - Dachwald, Bernd A1 - Wurm, P. T1 - Mission analysis for an advanced solar photon thruster T2 - 60th International Astronautical Congress 2009, IAC 2009 N2 - The so-called "compound solar sail", also known as "Solar Photon Thruster" (SPT), is a solar sail design concept, for which the two basic functions of the solar sail, namely light collection and thrust direction, are uncoupled. In this paper, we introduce a novel SPT concept, termed the Advanced Solar Photon Thruster (ASPT). This model does not suffer from the simplified assumptions that have been made for the analysis of compound solar sails in previous studies. We present the equations that describe the force, which acts on the ASPT. After a detailed design analysis, the performance of the ASPT with respect to the conventional flat solar sail (FSS) is investigated for three interplanetary mission scenarios: An Earth-Venus rendezvous, where the solar sail has to spiral towards the Sun, an Earth-Mars rendezvous, where the solar sail has to spiral away from the Sun, and an Earth-NEA rendezvous (to near-Earth asteroid 1996FG3), where a large orbital eccentricity change is required. The investigated solar sails have realistic near-term characteristic accelerations between 0.1 and 0.2mm/s2. Our results show that a SPT is not superior to the flat solar sail unless very idealistic assumptions are made. KW - Interplanetary flight Y1 - 2009 SN - 978-161567908-9 N1 - 60th International Astronautical Congress 2009, IAC 2009; Daejeon; South Korea; 12 October 2009 through 16 October 2009 VL - Vol. 8 SP - 6838 EP - 6851 PB - Elsevier CY - Amsterdam ER - TY - CHAP A1 - Götten, Falk A1 - Finger, Felix A1 - Havermann, Marc A1 - Braun, Carsten A1 - Marino, Matthew A1 - Bil, Cees T1 - Full Configuration Drag Estimation of Small-to-Medium Range UAVs and its Impact on Initial Sizing Optimization T2 - Deutscher Luft- und Raumfahrtkongress - DLRK 2020 Y1 - 2020 ER - TY - CHAP A1 - Bergmann, Ole A1 - Götten, Falk A1 - Braun, Carsten A1 - Janser, Frank T1 - Comparison and evaluation of blade element methods against RANS simulations and test data T2 - CEAS Aeronautical Journal N2 - This paper compares several blade element theory (BET) method-based propeller simulation tools, including an evaluation against static propeller ground tests and high-fidelity Reynolds-Average Navier Stokes (RANS) simulations. Two proprietary propeller geometries for paraglider applications are analysed in static and flight conditions. The RANS simulations are validated with the static test data and used as a reference for comparing the BET in flight conditions. The comparison includes the analysis of varying 2D aerodynamic airfoil parameters and different induced velocity calculation methods. The evaluation of the BET propeller simulation tools shows the strength of the BET tools compared to RANS simulations. The RANS simulations underpredict static experimental data within 10% relative error, while appropriate BET tools overpredict the RANS results by 15–20% relative error. A variation in 2D aerodynamic data depicts the need for highly accurate 2D data for accurate BET results. The nonlinear BET coupled with XFOIL for the 2D aerodynamic data matches best with RANS in static operation and flight conditions. The novel BET tool PropCODE combines both approaches and offers further correction models for highly accurate static and flight condition results. KW - BET KW - CFD propeller simulation KW - Propeller aerodynamics KW - Actuator disk modelling KW - Propeller performance Y1 - 2022 U6 - http://dx.doi.org/10.1007/s13272-022-00579-1 SN - 1869-5590 (Online) SN - 1869-5582 (Print) N1 - Corresponding author: Ole Bergmann VL - 13 SP - 535 EP - 557 PB - Springer CY - Wien ER - TY - CHAP A1 - Geiben, Benedikt A1 - Götten, Falk A1 - Havermann, Marc T1 - Aerodynamic analysis of a winged sub-orbital spaceplane T2 - Deutscher Luft- und Raumfahrtkongress - DLRK 2020 Y1 - 2020 ER - TY - CHAP A1 - Hippe, Jonas A1 - Finger, Felix A1 - Götten, Falk A1 - Braun, Carsten T1 - Propulsion System Qualification of a 25 kg VTOL-UAV: Hover Performance of Single and Coaxial Rotors and Wind-Tunnel Experiments on Cruise Propellers T2 - Deutscher Luft- und Raumfahrtkongress - DLRK 2020 Y1 - 2020 ER - TY - CHAP A1 - Finger, Felix A1 - Götten, Falk A1 - Braun, Carsten A1 - Bil, C. T1 - On Aircraft Design Under the Consideration of Hybrid-Electric Propulsion Systems T2 - APISAT 2018: The Proceedings of the 2018 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2018) N2 - A hybrid-electric propulsion system combines the advantages of fuel-based systems and battery powered systems and offers new design freedom. To take full advantage of this technology, aircraft designers must be aware of its key differences, compared to conventional, carbon-fuel based, propulsion systems. This paper gives an overview of the challenges and potential benefits associated with the design of aircraft that use hybrid-electric propulsion systems. It offers an introduction of the most popular hybrid-electric propulsion architectures and critically assess them against the conventional and fully electric propulsion configurations. The effects on operational aspects and design aspects are covered. Special consideration is given to the application of hybrid-electric propulsion technology to both unmanned and vertical take-off and landing aircraft. The authors conclude that electric propulsion technology has the potential to revolutionize aircraft design. However, new and innovative methods must be researched, to realize the full benefit of the technology. KW - Hybrid-electric aircraft KW - Aircraft design KW - Design rules KW - Green aircraft Y1 - 2019 SN - 978-981-13-3305-7 U6 - http://dx.doi.org/10.1007/978-981-13-3305-7_99 N1 - APISAT 2018 - Asia-Pacific International Symposium on Aerospace Technology. 16-18 October 2018. Chengdu, China. Lecture Notes in Electrical Engineering (LNEE, volume 459) SP - 1261 EP - 1272 PB - Springer CY - Singapore ER - TY - CHAP A1 - Götten, Falk A1 - Finger, Felix A1 - Braun, Carsten A1 - Havermann, Marc A1 - Bil, C. A1 - Gomez, F. T1 - Empirical Correlations for Geometry Build-Up of Fixed Wing Unmanned Air Vehicles T2 - APISAT 2018: The Proceedings of the 2018 Asia-Pacific International Symposium on Aerospace Technology (APISAT 2018) N2 - The results of a statistical investigation of 42 fixed-wing, small to medium sized (20 kg−1000 kg) reconnaissance unmanned air vehicles (UAVs) are presented. Regression analyses are used to identify correlations of the most relevant geometry dimensions with the UAV’s maximum take-off mass. The findings allow an empirical based geometry-build up for a complete unmanned aircraft by referring to its take-off mass only. This provides a bridge between very early design stages (initial sizing) and the later determination of shapes and dimensions. The correlations might be integrated into a UAV sizing environment and allow designers to implement more sophisticated drag and weight estimation methods in this process. Additional information on correlation factors for a rough drag estimation methodology indicate how this technique can significantly enhance the accuracy of early design iterations. KW - Unmanned Air Vehicle KW - Geometry KW - Correlations KW - Statistics KW - Drag Y1 - 2019 SN - 978-981-13-3305-7 U6 - http://dx.doi.org/10.1007/978-981-13-3305-7_109 N1 - APISAT 2018 - Asia-Pacific International Symposium on Aerospace Technology. 16-18 October 2018. Chengdu, China. Lecture Notes in Electrical Engineering (LNEE, volume 459) SP - 1365 EP - 1381 PB - Springer CY - Singapore ER -