Refine
Year of publication
Institute
- Fachbereich Luft- und Raumfahrttechnik (798) (remove)
Document Type
- Article (380)
- 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)
The paper presents the derivation of a new equivalent skin friction coefficient for estimating the parasitic drag of short-to-medium range fixed-wing unmanned aircraft. The new coefficient is derived from an aerodynamic analysis of ten different unmanned aircraft used for surveillance, reconnaissance, and search and rescue missions. The aircraft is simulated using a validated unsteady Reynolds-averaged Navier Stokes approach. The UAV’s parasitic drag is significantly influenced by the presence of miscellaneous components like fixed landing gears or electro-optical sensor turrets. These components are responsible for almost half of an unmanned aircraft’s total parasitic drag. The new equivalent skin friction coefficient accounts for these effects and is significantly higher compared to other aircraft categories. It is used to initially size an unmanned aircraft for a typical reconnaissance mission. The improved parasitic drag estimation yields a much heavier unmanned aircraft when compared to the sizing results using available drag data of manned aircraft.
The paper presents the derivation of a new equivalent skin friction coefficient for estimating the parasitic drag of short-to-medium range fixed-wing unmanned aircraft. The new coefficient is derived from an aerodynamic analysis of ten different unmanned aircraft used on surveillance, reconnaissance, and search and rescue missions. The aircraft are simulated using a validated unsteady Reynolds-averaged Navier Stokes approach. The UAV's parasitic drag is significantly influenced by the presence of miscellaneous components like fixed landing gears or electro-optical sensor turrets. These components are responsible for almost half of an unmanned aircraft's total parasitic drag. The new equivalent skin friction coefficient accounts for these effects and is significantly higher compared to other aircraft categories. It is used to initially size an unmanned aircraft for a typical reconnaissance mission. The improved parasitic drag estimation yields a much heavier unmanned aircraft when compared to the sizing results using available drag data of manned aircraft.
Searching optimal continuous-thrust trajectories is usually a difficult and time-consuming task. The solution quality of traditional optimal-control methods depends strongly on an adequate initial guess because the solution is typically close to the initial guess, which may be far from the (unknown) global optimum. Evolutionary neurocontrol attacks continuous-thrust optimization problems from the perspective of artificial intelligence and machine learning, combining artificial neural networks and evolutionary algorithms. This chapter describes the method and shows some example results for single- and multi-phase continuous-thrust trajectory optimization problems to assess its performance. Evolutionary neurocontrol can explore the trajectory search space more exhaustively than a human expert can do with traditional optimal-control methods. Especially for difficult problems, it usually finds solutions that are closer to the global optimum. Another fundamental advantage is that continuous-thrust trajectories can be optimized without an initial guess and without expert supervision.
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.
A technology reference study for a multiple near-Earth object (NEO) rendezvous mission with solar sailcraft is currently carried out by the authors of this paper. The investigated mission builds on previous concepts, but adopts a strong micro-spacecraft philosophy based on the DLR/ESA Gossamer technology. The main scientific objective of the mission is to explore the diversity of NEOs. After direct interplanetary insertion, the solar sailcraft should—within less than 10 years—rendezvous three NEOs that are not only scientifically interesting, but also from the point of human spaceight and planetary defense. In this paper, the objectives of the study are outlined and a preliminary potential mission profile is presented.
A technology reference study for a solar polar mission is presented. The study uses novel analytical methods to quantify the mission design space including the required sail performance to achieve a given solar polar observation angle within a given timeframe and thus to derive mass allocations for the remaining spacecraft sub-systems, that is excluding the solar sail sub-system. A parametric, bottom-up, system mass budget analysis is then used to establish the required sail technology to deliver a range of science payloads, and to establish where such payloads can be delivered to within a given timeframe. It is found that a solar polar mission requires a solar sail of side-length 100–125 m to deliver a ‘sufficient value’ minimum science payload, and that a 2.5 μm sail film substrate is typically required, however the design is much less sensitive to the boom specific mass.
A technology reference study for a displaced Lagrange point space weather mission is presented. The mission builds on previous concepts, but adopts a strong micro-spacecraft philosophy to deliver a low mass platform and payload which can be accommodated on the DLR/ESA Gossamer-3 technology demonstration mission. A direct escape from Geostationary Transfer Orbit is assumed with the sail deployed after the escape burn. The use of a miniaturized, low mass platform and payload then allows the Gossamer-3 solar sail to potentially double the warning time of space weather events. The mission profile and mass budgets will be presented to achieve these ambitious goals.
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.
Handbook of space technology
(2009)
Near-Earth asteroid (NEA) 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 less than 1 km-sized gravitational keyholes during its 2029-encounter. A pre-2029 kinetic impact is a very favorable option to nudge the asteroid out of a keyhole. The highest impact velocity and thus deflection can be achieved from a trajectory that is retrograde to Apophis orbit. With a chemical or electric propulsion system, however, many gravity assists and thus a long time is required to achieve this. We show in this paper that the solar sail might be the better propulsion system for such a mission: a solar sail Kinetic Energy Impactor (KEI) spacecraft could impact Apophis from a retrograde trajectory with a very high relative velocity (75-80 km/s) during one of its perihelion passages. The spacecraft consists of a 160 m × 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. For a launch in 2020, we also show that, even after Apophis has flown through one of the gravitational keyholes in 2029, the solar sail KEI concept is still feasible 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
The recovery of waste heat requires heat exchangers to extract it from a liquid or gaseous medium into another working medium, a refrigerant. In Organic Rankine Cycles (ORC) on Combustion Engines there are two major heat sources, the exhaust gas and the water/glycol fluid from the engine’s cooling circuit. A heat exchanger design must be adapted to the different requirements and conditions resulting from the heat sources, fluids, system configurations, geometric restrictions, and etcetera. The Stacked Shell Cooler (SSC) is a new and very specific design of a plate heat exchanger, created by AKG, which allows with a maximum degree of freedom the optimization of heat exchange rate and the reduction of the related pressure drop. This optimization in heat exchanger design for ORC systems is even more important, because it reduces the energy consumption of the system and therefore maximizes the increase in overall efficiency of the engine.
High resolution temperature measurement technique for materials sciences experiments in space
(1998)
Hochtemperaturtechnik
(1990)
Hochtemperaturtechnik. Interne Arbeitssitzung des GVC-Fachausschusses 'Hochtemperaturtechnik'
(1989)
How different diversity factors affect the perception of first-year requirements in higher education
(2021)
In the light of growing university entry rates, higher education institutions not only serve larger numbers of students, but also seek to meet first-year students’ ever more diverse needs. Yet to inform universities how to support the transition to higher education, research only offers limited insights. Current studies tend to either focus on the individual factors that affect student success or they highlight students’ social background and their educational biography in order to examine the achievement of selected, non-traditional groups of students. Both lines of research appear to lack integration and often fail to take organisational diversity into account, such as different types of higher education institutions or degree programmes. For a more comprehensive understanding of student diversity, the present study includes individual, social and organisational factors. To gain insights into their role for the transition to higher education, we examine how the different factors affect the students’ perception of the formal and informal requirements of the first year as more or less difficult to cope with. As the perceived requirements result from both the characteristics of the students and the institutional context, they allow to investigate transition at the interface of the micro and the meso level of higher education. Latent profile analyses revealed that there are no profiles with complex patterns of perception of the first-year requirements, but the identified groups rather differ in the overall level of perceived challenges. Moreover, SEM indicates that the differences in the perception largely depend on the individual factors self-efficacy and volition.
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.
Hydrostatic propeller drive
(2011)
Ice melting probes
(2023)
The exploration of icy environments in the solar system, such as the poles of Mars and the icy moons (a.k.a. ocean worlds), is a key aspect for understanding their astrobiological potential as well as for extraterrestrial resource inspection. On these worlds, ice melting probes are considered to be well suited for the robotic clean execution of such missions. In this chapter, we describe ice melting probes and their applications, the physics of ice melting and how the melting behavior can be modeled and simulated numerically, the challenges for ice melting, and the required key technologies to deal with those challenges. We also give an overview of existing ice melting probes and report some results and lessons learned from laboratory and field tests.
The ”IceMole“ is a novel maneuverable subsurface ice probe for clean in-situ analysis and sampling of subsurface ice and subglacial water/brine. It is developed and build at FH Aachen University of Applied Sciences’ Astronautical Laboratory. A first prototype was successfully tested on the Swiss Morteratsch glacier in 2010. Clean sampling is achieved with a hollow ice screw (as it is used in mountaineering) at the tip of the probe. Maneuverability is achieved with a differentially heated melting head. Funded by the German Space Agency (DLR), a consortium led by FH Aachen currently develops a much more advanced IceMole probe, which includes a sophisticated system for obstacle avoidance, target detection, and navigation in the ice. We intend to use this probe for taking clean samples of subglacial brine at the Blood Falls (McMurdo Dry Valleys, East Antarctica) for chemical and microbiological analysis. In our conference contribution, we 1) describe the IceMole design, 2) report the results of the field tests of the first prototype on the Morteratsch glacier, 3) discuss the probe’s potential for the clean in-situ analysis and sampling of subsurface ice and subglacial liquids, and 4) outline the way ahead in the development of this technology.
There is significant interest in sampling subglacial environments for geobiological studies, but they are difficult to access. Existing ice-drilling technologies make it cumbersome to maintain microbiologically clean access for sample acquisition and environmental stewardship of potentially fragile subglacial aquatic ecosystems. The IceMole is a maneuverable subsurface ice probe for clean in situ analysis and sampling of glacial ice and subglacial materials. The design is based on the novel concept of combining melting and mechanical propulsion. It can change melting direction by differential heating of the melting head and optional side-wall heaters. The first two prototypes were successfully tested between 2010 and 2012 on glaciers in Switzerland and Iceland. They demonstrated downward, horizontal and upward melting, as well as curve driving and dirt layer penetration. A more advanced probe is currently under development as part of the Enceladus Explorer (EnEx) project. It offers systems for obstacle avoidance, target detection, and navigation in ice. For the EnEx-IceMole, we will pay particular attention to clean protocols for the sampling of subglacial materials for biogeochemical analysis. We plan to use this probe for clean access into a unique subglacial aquatic environment at Blood Falls, Antarctica, with return of a subglacial brine sample.
We present the novel concept of a combined drilling and melting probe for subsurface ice research. This probe, named “IceMole”, is currently developed, built, and tested at the FH Aachen University of Applied Sciences’ Astronautical Laboratory. Here, we describe its first prototype design and report the results of its field tests on the Swiss Morteratsch glacier. Although the IceMole design is currently adapted to terrestrial glaciers and ice shields, it may later be modified for the subsurface in-situ investigation of extraterrestrial ice, e.g., on Mars, Europa, and Enceladus. If life exists on those bodies, it may be present in the ice (as life can also be found in the deep ice of Earth).