Refine
Year of publication
Institute
- Fachbereich Luft- und Raumfahrttechnik (797) (remove)
Document Type
- Article (379)
- Conference Proceeding (208)
- Book (107)
- Part of a Book (43)
- Patent (19)
- Report (14)
- Doctoral Thesis (10)
- Conference: Meeting Abstract (6)
- Other (3)
- Conference Poster (2)
Keywords
- Karosseriebau (6)
- Strömungsmaschine (6)
- Turbine (6)
- avalanche (6)
- solar sail (5)
- car body construction (4)
- hydrogen (4)
- snow (4)
- Eisschicht (3)
- GOSSAMER-1 (3)
- Hydrogen (3)
- MASCOT (3)
- Obstacle avoidance (3)
- Sonde (3)
- Strömungsausgleich (3)
- UAV (3)
- Wind Tunnel (3)
- Aeroelasticity (2)
- CFD (2)
- Drinfeld modules (2)
- Flight Test (2)
- Kraftfahrzeugbau (2)
- Leichtbau (2)
- Mars (2)
- Micromix (2)
- NOx emissions (2)
- PCM (2)
- Path planning (2)
- Pitching Moment (2)
- Solar sail (2)
- Spacecraft (2)
- Spaltentlastung (2)
- Sportwagen (2)
- Studentenprojekt (2)
- Trajectory Optimization (2)
- Transcendence (2)
- Virtuelle Fahrzeugentwicklung (2)
- Wave Drag (2)
- combustor development (2)
- fuels (2)
- industrial gas turbine (2)
- multiple NEA rendezvous (2)
- small spacecraft (2)
- t-modules (2)
- 1P hub loads (1)
- Active humidity control (1)
- Actuator disk modelling (1)
- Aerodynamic Drag (1)
- Aircraft design (1)
- Aircraft sizing (1)
- Analogue Environments (1)
- Ansaugsystem (1)
- Antarctic Glaciology (1)
- Antarctica (1)
- Asteroid Deflection (1)
- Atmospheres (1)
- Attitude dynamics (1)
- Autofluoreszenzverfahren (1)
- Automated Optimization (1)
- Automotive safety approach (1)
- Autonomy (1)
- Avalanche (1)
- BET (1)
- Bio-inspired systems (1)
- Blade element method (1)
- Bumblebees (1)
- CFD propeller simulation (1)
- CO2 emission reduction targets (1)
- Capacity Building Higher Education (1)
- Carsharing (1)
- Centrifugal twisting moment (1)
- Certification Rule (1)
- Combustion (1)
- Commercial Vehicle (1)
- Common Rail Injection System (1)
- Correlations (1)
- Cost function (1)
- Crashworthiness (1)
- Cryobot (1)
- DLR-ESTEC GOSSAMER roadmap for solar sailing (1)
- Design rules (1)
- Diesel Engine (1)
- Direkteinblasung (1)
- Drag (1)
- Drag Reduction (1)
- Drag estimation (1)
- Driving cycle recognition (1)
- Dry-low-NOx (DLN) combustion (1)
- Dynamic modeling (1)
- ECMS (1)
- ESATAN (1)
- ESATAN-TMS (1)
- Electrical Flight (1)
- Electrical vehicle (1)
- Electrochemical impedance spectroscopy (1)
- Emissions (1)
- Energy management strategies (1)
- Engine Efficiency (1)
- Epistemische Neugier (1)
- Erasmus+ United (1)
- European Framework and South East Asia (1)
- European Transient Cycle (1)
- Evacuation Rule (1)
- Evolutionary Neurocontrol (1)
- Exoplanet (1)
- Extension–twist coupling (1)
- Extraterrestrial Glaciology (1)
- Fault detection (1)
- Finite element method (1)
- Flame residence time (1)
- Flame temperature (1)
- Flight Mechanics (1)
- Flight Tests (1)
- Flight control (1)
- Flutter (1)
- Friction Drag (1)
- Fuel cell (1)
- Fuel-flexibility (1)
- Full-vehicle crash test (1)
- GEO (1)
- Gas turbine combustion (1)
- Geometry (1)
- Glaciological instruments and methods (1)
- Gossamer (1)
- Gossamer structures (1)
- Green aircraft (1)
- Guide Tube (1)
- Health management system (1)
- High hydrogen combustion (1)
- Higher derivations (1)
- Human factors (1)
- Hybrid Propellants (1)
- Hybrid-electric aircraft (1)
- Hydrogen combustion (1)
- Hydrogen gas turbine (1)
- Hyperdifferentials (1)
- ITS (1)
- Ice Melting (1)
- Ice melting probe (1)
- Ice penetration (1)
- Icy Moons (1)
- Icy moons (1)
- Impedance analysis (1)
- Inflight Regeneration, Recuperation (1)
- Infused Thermal Solutions (1)
- Interplanetary flight (1)
- Interstellar objects (1)
- Jupiter (1)
- Kalman filter (1)
- Karosserieleichtbau (1)
- Karosserietechnik (1)
- LEO (1)
- Ladungswechsel (1)
- Laminare Strömung (1)
- Laminarprofil (1)
- Leading Edge Vortex (1)
- Leichtbauwerkstoffe (1)
- Lichtstreuungsbasierte Instrumente (1)
- Lifting propeller (1)
- Lightweight car body construction (1)
- Local path planning (1)
- Low NOx (1)
- Low emission (1)
- Low-Thrust Propulsion (1)
- Low-field NMR (1)
- Lunar Surface (1)
- MAV (1)
- Mach Number (1)
- Malaysian Automotive Industry (1)
- Malaysian automotive industry (1)
- Materialmischbauweise (1)
- Melting Efficiency (1)
- Melting Performance (1)
- Melting Probe (1)
- Micromix combustion (1)
- Missions (1)
- Multi-objective optimization (1)
- Multidisciplinary Design Optimization (1)
- Multiphase (1)
- Multirotor UAS (1)
- NMR exchange relaxometry (1)
- NOx (1)
- Noise Exposure (1)
- Non-model-based Evaluation (1)
- Nozzle (1)
- Ocean Worlds (1)
- Ocean worlds (1)
- Online diagnostic (1)
- Orbital dynamics (1)
- PEM fuel cell (1)
- PEM fuel cells (1)
- PHILAE (1)
- Parabolized Stability Equation (1)
- Parasitic drag (1)
- Passenger compartment (1)
- Payload (1)
- Periods (1)
- Planetary Protection (1)
- Planetary exploration (1)
- Predictive battery discharge (1)
- Profilumströmung (1)
- Propeller (1)
- Propeller Aerodynamics (1)
- Propeller aerodynamics (1)
- Propeller elasticity (1)
- Propeller performance (1)
- Propeller whirl flutter (1)
- RAMMS (1)
- RaWid (1)
- Relative air humidity (1)
- Reusable Rocket Engines (1)
- Selbstwirksamkeit (1)
- Selective Catalytic Reduction (1)
- Sequence-Search (1)
- Severe Accident (1)
- Small Solar System Body Lander (1)
- Small Spacecraft (1)
- Small spacecraft (1)
- Snow (1)
- Solar Power Sail (1)
- Solar Sail (1)
- Sonic Boom (1)
- Spacecraft Trajectory Optimization (1)
- Spaltentlasung (1)
- Specific Fuel Consumption (1)
- Spectroscopy (1)
- Stahlblech-Leichtmetall Verbundguss (1)
- Stahlblech-Leichtmetall-Hybride (1)
- Statistics (1)
- Strömungssonde (1)
- Subclacial exploration (1)
- Subglacial lakes (1)
- Suction (1)
- Supersonic Flow (1)
- Supersonic Wind Tunnel (1)
- TICTOP (1)
- Technology Challenge (1)
- Technology Transfer (1)
- Thermal Fatigue Testing (1)
- Thermal Model (1)
- Thermal analysis (1)
- Thermal comfort (1)
- Thermal management (1)
- Trajectories (1)
- Transit (1)
- Trapeze effect (1)
- UTeM Engineering Knowledge Transfer Unit (1)
- Unmanned Air Vehicle (1)
- Unmanned aerial vehicles (1)
- Unsteady aerodynamics (1)
- Variable Geometry (1)
- Verbrennungsmotor (1)
- Verbundguss (1)
- Wasserstoff (1)
- Wind milling (1)
- Wind tunnel experiments (1)
- adaptive systems (1)
- aircraft engine (1)
- artificial intelligence (1)
- assistance system (1)
- asteroid lander (1)
- asteroid sample return (1)
- attitude dynamics (1)
- autofluorescence-based detection system (1)
- aviation application (1)
- combustion (1)
- combustor (1)
- contamination (1)
- control system (1)
- debris flow (1)
- eVTOL development (1)
- eVTOL safety (1)
- electrically driven compressors (1)
- electro mobility (1)
- emission (1)
- emission index (1)
- engine demonstration (1)
- flotilla missions (1)
- fuel cell (1)
- fuel cell systems (1)
- fuel cell vehicle (1)
- gamification (1)
- gas turbine (1)
- habitability (1)
- health management systems (1)
- heliosphere (1)
- hybrid laminar flow (1)
- ice moons (1)
- icy moons (1)
- intelligent control (1)
- intelligent energy management (1)
- internal combustion engine (1)
- intrinsische Motivation (1)
- ion propulsion (1)
- latent heat (1)
- lattice (1)
- life detection (1)
- light scattering analysis (1)
- low-thrust (1)
- low-thrust trajectory optimization (1)
- machine learning (1)
- manufacturing (1)
- near-Earth asteroid (1)
- nitric oxides (1)
- operational aspects (1)
- optimization system (1)
- orbit control (1)
- orbital dynamics (1)
- passive thermal control (1)
- planetary defence (1)
- responsive space (1)
- sailcraft (1)
- sample return (1)
- small solar system body characterisation (1)
- small spacecraft asteroid lander (1)
- small spacecraft solar sail (1)
- solar sails (1)
- solar system (1)
- space missions (1)
- star tracker (1)
- subglacial aquatic ecosystems (1)
- subroutine (1)
- subsurface ice (1)
- subsurface ice research (1)
- subsurface probe (1)
- suction structure (1)
- suction systems (1)
- system engineering (1)
- technology transfer (1)
- thermo-physical (1)
- underwater vehicle (1)
- vollvariabler Ventilbetrieb (1)
We propose a simple parametric OSSD 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.
With the increased interest for interstellar exploration after the discovery of exoplanets and the proposal by Breakthrough Starshot, this paper investigates the optimisation of photon-sail trajectories in Alpha Centauri. The prime objective is to find the optimal steering strategy for a photonic sail to get captured around one of the stars after a minimum-time transfer from Earth. By extending the idea of the Breakthrough Starshot project with a deceleration phase upon arrival, the mission’s scientific yield will be increased. As a secondary objective, transfer trajectories between the stars and orbit-raising manoeuvres to explore the habitable zones of the stars are investigated. All trajectories are optimised for minimum time of flight using the trajectory optimisation software InTrance. Depending on the sail technology, interstellar travel times of 77.6-18,790 years can be achieved, which presents an average improvement of 30% with respect to previous work. Still, significant technological development is required to reach and be captured in the Alpha-Centauri system in less than a century. Therefore, a fly-through mission arguably remains the only option for a first exploratory mission to Alpha Centauri, but the enticing results obtained in this work provide perspective for future long-residence missions to our closest neighbouring star system.
Optimization of Interplanetary Rendezvous Trajectories for Solar Sailcraft Using a Neurocontroller
(2002)
Searching optimal interplanetary trajectories for low-thrust spacecraft is usually a difficult and time-consuming task that involves much experience and expert knowledge in astrodynamics and optimal control theory. This is because the convergence behavior of traditional local optimizers, which are based on numerical optimal control methods, depends on an adequate initial guess, which is often hard to find, especially for very-low-thrust trajectories that necessitate many revolutions around the sun. The obtained solutions are typically close to the initial guess that is rarely close to the (unknown) global optimum. Within this paper, trajectory optimization problems are attacked from the perspective of artificial intelligence and machine learning. Inspired by natural archetypes, a smart global method for low-thrust trajectory optimization is proposed that fuses artificial neural networks and evolutionary algorithms into so-called evolutionary neurocontrollers. This novel method runs without an initial guess and does not require the attendance of an expert in astrodynamics and optimal control theory. This paper details how evolutionary neurocontrol works and how it could be implemented. The performance of the method is assessed for three different interplanetary missions with a thrust to mass ratio <0.15mN/kg (solar sail and nuclear electric).
Optical Instruments require an extremely stable thermal surrounding to prevent loss of data quality by misalignments of the instrument components resulting from material deformation due to temperature f luctuations (e.g. from solar intrusion). Phase Change Material (PCM) can be applied as a thermal damper to achieve a more uniform temperature distribution. The challenge of this method is, among others, the integration of PCM into affected areas. If correctly designed, incoming heat is latently absorbed during phase change of the PCM, i.e. the temperature of a structure remains almost constant. In a cold phase, the heat during phase change is released again latently until the PCM returns to its original state of aggregation. Thus, the structure is thermally stabilized. At FH Aachen– University of Applied Sciences research is conducted to apply PCM directly into the structures of affected components (baffles, optical benches, electronic boxes, etc.). Through the application of Additive Manufacturing, the necessary voids are directly printed into these structures and filled later with PCM. Additive Manufacturing enables complex structures that would not have been possible with conservative manufacturing methods. A corresponding Breadboard was developed and manufactured by Selective Laser Melting (SLM). The current state of research includes the handling and analysis of the Breadboard, tests and a correlation of the thermal model. The results have shown analytically and practically that it is possible to use PCM as an integral part of the structure as a thermal damper. The results serve as a basis for the further development of the technology, which should maximize performance and enable the integration of PCM into much more complex structures.
This dataset was acquired at field tests of the steerable ice-melting probe "EnEx-IceMole" (Dachwald et al., 2014). A field test in summer 2014 was used to test the melting probe's system, before the probe was shipped to Antarctica, where, in international cooperation with the MIDGE project, the objective of a sampling mission in the southern hemisphere summer 2014/2015 was to return a clean englacial sample from the subglacial brine reservoir supplying the Blood Falls at Taylor Glacier (Badgeley et al., 2017, German et al., 2021).
The standardized log-files generated by the IceMole during melting operation include more than 100 operational parameters, housekeeping information, and error states, which are reported to the base station in intervals of 4 s. Occasional packet loss in data transmission resulted in a sparse number of increased sampling intervals, which where compensated for by linear interpolation during post processing. The presented dataset is based on a subset of this data: The penetration distance is calculated based on the ice screw drive encoder signal, providing the rate of rotation, and the screw's thread pitch. The melting speed is calculated from the same data, assuming the rate of rotation to be constant over one sampling interval. The contact force is calculated from the longitudinal screw force, which es measured by strain gauges. The used heating power is calculated from binary states of all heating elements, which can only be either switched on or off. Temperatures are measured at each heating element and averaged for three zones (melting head, side-wall heaters and back-plate heaters).
Solar sailcraft provide a wide range of opportunities for high-energy low-cost missions. To date, most mission studies require a rather demanding performance that will not be realized by solar sailcraft of the first generation.
However, even with solar sailcraft of moderate performance, scientifically relevant missions are feasible. This is demonstrated with a Near Earth Asteroid sample return mission and various planetary rendezvous missions.
Die urbane Mobilität ist im Wandel und insbesondere neue innovative Geschäftsmodelle werden einen wesentlichen Teil zur Lösung von künftigen Mobilitätsbedürfnissen beitragen. Die sogenannte „Shared Mobility“ gilt aktuell neben der Elektrifizierung des Antriebes und autonomem Fahrzeugtechnologien als einer der wichtigsten Trendthemen in der Automobilindustrie. Neue Mobilitätsdienstleistungen verlangen dabei verstärkt auch neue Fahrzeugkonzepte.
Solar-electric propulsion (SEP) is superior with
respect to payload capacity, flight time and
flexible launch window to the conventional
interplanetary transfer method using chemical
propulsion combined with gravity assists. This fact
results from the large exhaust velocities of electric
low–thrust propulsion and is favourable also for
missions to the giant planets, Kuiper-belt objects
and even for a heliopause probe (IHP) as shown in
three studies by the authors funded by DLR. They
dealt with a lander for Europa and a sample return
mission from a mainbelt asteroid [1], with the
TANDEM mission [2]; the third recent one
investigates electric propulsion for the transfer to
the edge of the solar system.
All studies are based on triple-junction solar arrays,
on rf-ion thrusters of the qualified RIT-22 type and
they use the intelligent trajectory optimization
program InTrance [3].
Die autonome, unbemannte Luftfahrt ist einer der Schlüsselsektoren für die Zukunft der Luftfahrt. In diesem rasant wachsenden Bereich nehmen senkrecht startende und senkrecht landende Flugzeuge (Vertical Take-Off and Landing – VTOL) einen besonderen Platz ein. Ein VTOL-Flugzeug (manchmal auch „Transitionsfluggerät“ genannt) verbindet die Eigenschaft des Helikopters, überall starten und landen zu können, mit den Geschwindigkeits-, Reichweiten und Flugdauervorteilen des Starrflüglers. Grundsätzlich wird die Senkrechtstart- und -landefähigkeit sowohl von zivilen als auch von militärischen Betreibern unbemannter Fluggeräte (UAVs) gewünscht. Trotzdem bietet der Markt nur eine geringe Anzahl von VTOL-UAVs, da qualitativ hochwertige Entwürfe eine ausgesprochene Herausforderung in der Entwicklung darstellen. An der FH Aachen wird deshalb seit über 5 Jahren an der Auslegung und Analyse von solchen unbemannten VTOL Flugzeugen geforscht. Das neuste Projekt ist der Eigenentwurf einer großen, senkrechtstartenden Transportdrohne. Das „PhoenAIX“ getaufte Fluggerät wird von Falk Götten und Felix Finger im Rahmen einer EFRE-Förderung entwickelt.
Picosecond dynamics in haemoglobin from different species: A quasielastic neutron scattering study
(2014)
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.
This work proposes a hybrid algorithm combining an Artificial Neural Network (ANN) with a conventional local path planner to navigate UAVs efficiently in various unknown urban environments. The proposed method of a Hybrid Artificial Neural Network Avoidance System is called HANNAS. The ANN analyses a video stream and classifies the current environment. This information about the current Environment is used to set several control parameters of a conventional local path planner, the 3DVFH*. The local path planner then plans the path toward a specific goal point based on distance data from a depth camera. We trained and tested a state-of-the-art image segmentation algorithm, PP-LiteSeg. The proposed HANNAS method reaches a failure probability of 17%, which is less than half the failure probability of the baseline and around half the failure probability of an improved, bio-inspired version of the 3DVFH*. The proposed HANNAS method does not show any disadvantages regarding flight time or flight distance.
In general aviation, too, it is desirable to be able to operate existing internal combustion engines with fuels that produce less CO₂ than Avgas 100LL being widely used today It can be assumed that, in comparison, the fuels CNG, LPG or LNG, which are gaseous under normal conditions, produce significantly lower emissions. Necessary propulsion system adaptations were investigated as part of a research project at Aachen University of Applied Sciences.
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.