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)
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.
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.
This paper presents an approach for UAV propulsion system qualification and validation on the example of FH Aachen's 25 kg cargo UAV "PhoenAIX". Thrust and power consumption are the most important aspects of a propulsion system's layout. In the initial design phase, manufacturers' data has to be trusted, but the validation of components is an essential step in the design process. This process is presented in this paper. The vertical takeoff system is designed for efficient hover; therefore, performance under static conditions is paramount. Because an octo-copter layout with coaxial rotors is considered, the impact of this design choice is analyzed. Data on thrust, voltage stability, power consumption, rotational speed, and temperature development of motors and controllers are presented for different rotors. The fixed-wing propulsion system is designed for efficient cruise flight. At the same time, a certain static thrust has to be provided, as the aircraft needs to accelerate to cruise speed. As for the hover-system, data on different propellers is compared. The measurements were taken for static conditions, as well as for different inflow velocities, using the FH-Aachen's wind-tunnel.
This paper primarily presents an aerodynamic CFD analysis of a winged spaceplane geometry based on the Japanese Space Walker proposal. StarCCM was used to calculate aerodynamic coefficients for a typical space flight trajectory including super-, trans- and subsonic Mach numbers and two angles of attack. Since the solution of the RANS equations in such supersonic flight regimes is still computationally expensive, inviscid Euler simulations can principally lead to a significant reduction in computational effort. The impact on accuracy of aerodynamic properties is further analysed by comparing both methods for different flight regimes up to a Mach number of 4.
Comparative assessment of parallel-hybrid-electric propulsion systems for four different aircraft
(2020)
Until electric energy storage systems are ready to allow fully electric aircraft, the combination of combustion engine and electric motor as a hybrid-electric propulsion system seems to be a promising intermediate solution. Consequently, the design space for future aircraft is expanded considerably, as serial hybrid-electric, parallel hybrid-electric, fully electric, and conventional propulsion systems must all be considered. While the best propulsion system depends on a multitude of requirements and considerations, trends can be observed for certain types of aircraft and certain types of missions. This Paper provides insight into some factors that drive a new design toward either conventional or hybrid propulsion systems. General aviation aircraft, regional transport aircraft vertical takeoff and landing air taxis, and unmanned aerial vehicles are chosen as case studies. Typical missions for each class are considered, and the aircraft are analyzed regarding their takeoff mass and primary energy consumption. For these case studies, a high-level approach is chosen, using an initial sizing methodology. Only parallel-hybrid-electric powertrains are taken into account. Aeropropulsive interaction effects are neglected. Results indicate that hybrid-electric propulsion systems should be considered if the propulsion system is sized by short-duration power constraints. However, if the propulsion system is sized by a continuous power requirement, hybrid-electric systems offer hardly any benefit.
Thermal Characterization of additive manufactured Integral Structures for Phase Change Applications
(2020)
“Infused Thermal Solutions” (ITS) introduces a method for passive thermal control to stabilize structural components thermally without active heating and cooling systems, by using phase change material (PCM) in combination with lattice – both embedded into an additive manufactured integral structure. The technology is currently under development. This paper presents the results of the thermal property measurements performed on additive manufactured ITS breadboards. Within the breadboard campaigns key characteristics of the additive manufactured specimens were derived: Mechanical parameters: specimen impermeability, minimum wall thickness, lattice structure, subsequent heat treatment. Thermal properties: thermo-optical surface properties of the additive manufactured raw material, thermal conductivity and specific heat capacity measurements. As a conclusion the paper introduces an overview of potential ITS hardware applications, expected to increase the thermal performance.
The recently discovered first high velocity hyperbolic objects passing through the Solar System, 1I/'Oumuamua and 2I/Borisov, have raised the question about near term missions to Interstellar Objects. In situ spacecraft exploration of these objects will allow the direct determination of both their structure and their chemical and isotopic composition, enabling an entirely new way of studying small bodies from outside our solar system. In this paper, we map various Interstellar Object classes to mission types, demonstrating that missions to a range of Interstellar Object classes are feasible, using existing or near-term technology. We describe flyby, rendezvous and sample return missions to interstellar objects, showing various ways to explore these bodies characterizing their surface, dynamics, structure and composition. Interstellar objects likely formed very far from the solar system in both time and space; their direct exploration will constrain their formation and history, situating them within the dynamical and chemical evolution of the Galaxy. These mission types also provide the opportunity to explore solar system bodies and perform measurements in the far outer solar system.
We generalize our work on Carlitz prime power torsion extension to torsion extensions of Drinfeld modules of arbitrary rank. As in the Carlitz case, we give a description of these extensions in terms of evaluations of Anderson generating functions and their hyperderivatives at roots of unity. We also give a direct proof that the image of the Galois representation attached to the p-adic Tate module lies in the p-adic points of the motivic Galois group. This is a generalization of the corresponding result of Chang and Papanikolas for the t-adic case.
This paper presents a novel method for airfoil drag estimation at Reynolds numbers between 4×10⁵ and 4×10⁶. The novel method is based on a systematic study of 40 airfoils applying over 600 numerical simulations and considering natural transition. The influence of the airfoil thickness-to-chord ratio, camber, and freestream Reynolds number on both friction and pressure drag is analyzed in detail. Natural transition significantly affects drag characteristics and leads to distinct drag minima for different Reynolds numbers and thickness-to-chord ratios. The results of the systematic study are used to develop empirical correlations that can accurately predict an airfoil drag at low-lift conditions. The new approach estimates a transition location based on airfoil thickness-to-chord ratio, camber, and Reynolds number. It uses the transition location in a mixed laminar–turbulent skin-friction calculation, and corrects the skin-friction coefficient for separation effects. Pressure drag is estimated separately based on correlations of thickness-to-chord ratio, camber, and Reynolds number. The novel method shows excellent accuracy when compared with wind-tunnel measurements of multiple airfoils. It is easily integrable into existing aircraft design environments and is highly beneficial in the conceptual design stage.
It is investigated whether a nonrotating lifting fan remaining uncovered during cruise flight, as opposed to being covered by a shutter system, can be realized with limited additional drag and loss of lift during cruise flight. A wind-tunnel study of a wing-embedded lifting fan has been conducted at the Side Wind Test Facility Göttingen of DLR, German Aerospace Center in Göttingen using force, pressure, and stereoscopic particle image velocimetry techniques. The study showed that a step on the lower side of the wing in front of the lifting fan duct increases the lift-to-drag ratio of the whole model by up to 25% for all positive angles of attack. Different sizes and inclinations of the step had limited influence on the surface pressure distribution. The data indicate that these parameters can be optimized to maximize the lift-to-drag ratio. A doubling of the curvature radius of the lifting fan duct inlet lip on the upper side of the wing affected the lift-to-drag ratio by less than 1%. The lifting fan duct inlet curvature can therefore be optimized to maximize the vertical fan thrust of the rotating lifting fan during hovering without affecting the cruise flight performance with a nonrotating fan.
To meet the challenges of manufacturing smart products, the manufacturing plants have been radically changed to become smart factories underpinned by industry 4.0 technologies. The transformation is assisted by employment of machine learning techniques that can deal with modeling both big or limited data. This manuscript reviews these concepts and present a case study that demonstrates the use of a novel intelligent hybrid algorithms for Industry 4.0 applications with limited data. In particular, an intelligent algorithm is proposed for robust data modeling of nonlinear systems based on input-output data. In our approach, a novel hybrid data-driven combining the Group-Method of Data-Handling and Singular-Value Decomposition is adapted to find an offline deterministic model combined with Pareto multi-objective optimization to overcome the overfitting issue. An Unscented-Kalman-Filter is also incorporated to update the coefficient of the deterministic model and increase its robustness against data uncertainties. The effectiveness of the proposed method is examined on a set of real industrial measurements.
In this chapter, the key technologies and the instrumentation required for the subsurface exploration of ocean worlds are discussed. The focus is laid on Jupiter’s moon Europa and Saturn’s moon Enceladus because they have the highest potential for such missions in the near future. The exploration of their oceans requires landing on the surface, penetrating the thick ice shell with an ice-penetrating probe, and probably diving with an underwater vehicle through dozens of kilometers of water to the ocean floor, to have the chance to find life, if it exists. Technologically, such missions are extremely challenging. The required key technologies include power generation, communications, pressure resistance, radiation hardness, corrosion protection, navigation, miniaturization, autonomy, and sterilization and cleaning. Simpler mission concepts involve impactors and penetrators or – in the case of Enceladus – plume-fly-through missions.
Manufacturing Process Simulation for the Prediction of Tool-Part-Interaction and Ply Wrinkling
(2015)
Manufacturing Process Simulation for the Prediction of Tool-Part-Interaction and Ply Wrinkling
(2019)
Manufacturing process simulation enables the evaluation and improvement of autoclave mold concepts early in the design phase. To achieve a high part quality at low cycle times, the thermal behavior of the autoclave mold can be investigated by means of simulations. Most challenging for such a simulation is the generation of necessary boundary conditions. Heat-up and temperature distribution in an autoclave mold are governed by flow phenomena, tooling material and shape, position within the autoclave, and the chosen autoclave cycle. This paper identifies and summarizes the most important factors influencing mold heat-up and how they can be introduced into a thermal simulation. Thermal measurements are used to quantify the impact of the various parameters. Finally, the gained knowledge is applied to develop a semi-empirical approach for boundary condition estimation that enables a simple and fast thermal simulation of the autoclave curing process with reasonably high accuracy for tooling optimization.