TY  - JOUR
A1  - Wilson, T. L.
A1  - Blome, Hans-Joachim
T1  - The Pioneer anomaly and a rotating Gödel universe
JF  - Advances in Space Research
Y1  - 2009
SN  - 0273-1177
VL  - 44
IS  - 11
SP  - 1345
EP  - 1353
ER  - 
TY  - CHAP
A1  - Spurmann, Jörn
A1  - Ohndorf, Andreas
A1  - Dachwald, Bernd
A1  - Seboldt, Wolfgang
A1  - Löb, Horst
A1  - Schartner, Karl-Heinz
T1  - Interplanetary trajectory optimization for a sep mission to Saturn
T2  - 60th International Astronautical Congress 2009
N2  - The recently proposed NASA and ESA missions to Saturn and Jupiter pose difficult tasks to mission designers because chemical propulsion scenarios are not capable of transferring heavy spacecraft into the outer solar system without the use of gravity assists. Thus our developed mission scenario based on the joint NASA/ESA Titan Saturn System Mission baselines solar electric propulsion to improve mission flexibility and transfer time. For the calculation of near-globally optimal low-thrust trajectories, we have used a method called Evolutionary Neurocontrol, which is implemented in the low-thrust trajectory optimization software InTrance. The studied solar electric propulsion scenario covers trajectory optimization of the interplanetary transfer including variations of the spacecraft's thrust level, the thrust unit's specific impulse and the solar power generator power level. Additionally developed software extensions enabled trajectory optimization with launcher-provided hyperbolic excess energy, a complex solar power generator model and a variable specific impulse ion engine model. For the investigated mission scenario, Evolutionary Neurocontrol yields good optimization results, which also hold valid for the more elaborate spacecraft models. Compared to Cassini/Huygens, the best found solutions have faster transfer times and a higher mission flexibility in general.
KW  - Spacecraft
KW  - Reusable Rocket Engines
KW  - Hybrid Propellants
Y1  - 2009
SN  - 9781615679089
N1  - 60th International Astronautical Congress 2009 (IAC 2009)
Held 12-16 October 2009, Daejeon, Republic of Korea.
SP  - 5234
EP  - 5248
ER  - 
TY  - CHAP
A1  - Schartner, Karl-Heinz
A1  - Loeb, H. W.
A1  - Dachwald, Bernd
A1  - Ohndorf, Andreas
T1  - Perspectives of electric propulsion for outer planetary and deep space missions
T2  - European Planetary Science Congress 2009
N2  - 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].
Y1  - 2009
N1  - European Planetary Science Congress 2009, 13-18 September, Potsdam, Germany
SP  - 416
EP  - 416
ER  - 
TY  - CHAP
A1  - Kemper, Hans
A1  - Hellenbroich, Gereon
A1  - Esch, Thomas
T1  - Concept of an innovative passenger-car hybrid drive for European driving conditions
T2  - Hybrid vehicles and energy management : 6th symposium ; 18th and 19th February 2009, Stadthalle Braunschweig
N2  - The downsizing of spark ignition engines in conjunction with turbocharging is considered to be a promising method for reducing CO₂ emissions. Using this concept, FEV has developed a new, highly efficient drivetrain to demonstrate fuel consumption reduction and drivability in a vehicle based on the Ford Focus ST. The newly designed 1.8L turbocharged gasoline engine incorporates infinitely variable intake and outlet control timing and direct fuel injection utilizing piezo injectors centrally located. In addition, this engine uses a prototype FEV engine control system, with software that was developed and adapted entirely by FEV. The vehicle features a 160 kW engine with a maximum mean effective pressure of 22.4 bar and 34 % savings in simulated fuel consumption. During the first stage, a new electrohydraulically actuated hybrid transmission with seven forward gears and one reverse gear and a single dry starting clutch will be integrated. The electric motor of the hybrid is directly connected to the gear set of the transmission. Utilizing the special gear set layout, the electric motor can provide boost during a change of gears, so that there is no interruption in traction. Therefore, the transmission system combines the advantages of a double clutch controlled gear change (gear change without an interruption in traction) with the efficient, cost-effective design of an automated manual transmission system. Additionally, the transmission provides a purely electric drive system and the operation of an air-conditioning compressor during the engine stop phases. One other alternative is through the use of CAI (Controlled Auto Ignition), which incorporates a process developed by FEV for controlled compression ignition.
Y1  - 2009
SN  - 978-3-937655-20-8
SP  - 264
EP  - 287
PB  - Gesamtzentrum für Verkehr (GZVB)
CY  - Braunschweig
ER  - 
TY  - CHAP
A1  - Funke, Harald
A1  - Esch, Thomas
A1  - Roosen, Peter
ED  - Bartz, Wilfried J.
T1  - Using motor gasoline for aircrafts - coping with growing bio-fuel-caused risks by understanding cause-effect relationship
T2  - Fuels 2009 : mineral oil based and alternative fuels ; 7th international colloquium ; January 14 - 15, 2009
N2  - The utilisation of vehicle-oriented gasoline in general aviation is very desirable for both ecological and economical reasons, as well as for general considerations of availability. As of today vehicle fuels may be used if the respective engine and cell are certified for such an operation. For older planes a supplementary technical certificate is provided for gasoline mixtures with less than 1 % v/v ethanol only, though. Larger admixtures of ethanol may lead to sudden engine malfunction and should be considered as considerable security risks. Major problems are caused by the partially ethanol non-withstanding materials, a necessarily changed stochiometric adjustment of the engine for varying ethanol shares and the tendency for phase separation in the presence of absorbed water. The concepts of the flexible fuel vehicles are only partially applicable in the view of air security.
Y1  - 2009
SN  - 978-3-924813-75-8
SP  - 237
EP  - 244
PB  - Technische Akademie Esslingen (TAE)
CY  - Ostfildern
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  - 8
SP  - 6838
EP  - 6851
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Funke, Harald
A1  - Börner, Sebastian
A1  - Robinson, A.
A1  - Hendrick, P.
A1  - Recker, E.
T1  - Low NOx H2 combustion for industrial gas turbines of various power ranges
JF  - 5th International Gas Turbine Conference ETN-IGTC, ETN-2010-42, Brussels, Belgium, October 2010
Y1  - 2010
ER  - 
TY  - JOUR
A1  - Recker, Elmar
A1  - Bosschaerts, Walter
A1  - Wagemakers, Rolf
A1  - Hendrick, Patrick
A1  - Funke, Harald
A1  - Börner, Sebastian
T1  - Experimental study of a round jet in cross-flow at low momentum ratio
JF  - 15th International Symposium on Applications of Laser Techniques to Fluid Mechanics Lisbon, Portugal, 05-08 July, 2010 - 1
Y1  - 2010
SP  - 1
EP  - 13
ER  - 
TY  - JOUR
A1  - Funke, Harald
A1  - Robinson, A. E.
A1  - Hendrick, P.
A1  - Wagemakers, R.
T1  - Design and Testing of a Micromix Combustor With Recuperative Wall Cooling for a Hydrogen Fuelled µ-Scale Gas Turbine
JF  - Proceedings of the ASME Turbo Expo 2010 : presented at the 2010 ASME Turbo Expo, June 14 - 18, 2010, Glasgow, UK / sponsored by the International Gas Turbine Institute / Vol. 5: Industrial and cogeneration ; microturbines and small turbomachinery ; oil and gas applications ; wind turbine technology
Y1  - 2010
SN  - 978-0-7918-4400-7
N1  - GT2010-23453 ; ASME Turbo Expo ; (Glasgow) : 2010.06.14-18
SP  - 587
EP  - 596
PB  - ASME
CY  - New York, NY
ER  - 
TY  - JOUR
A1  - Maiwald, Volker
A1  - Dachwald, Bernd
T1  - Mission Design for a Multiple-Rendezvous Mission to Jupiter's Trojans
Y1  - 2010
N1  - COSPAR 2010 ; 38th COSPAR Scientific Assembly. Held 18-25 July 2010 in Bremen, Germany [Abstract]
SP  - 3
ER  - 
TY  - JOUR
A1  - Börner, Sebastian
A1  - Funke, Harald
A1  - Hendrick, P.
A1  - Recker, E.
T1  - Control system modifications for a hydrogen fuelled gas-turbine
JF  - ISROMAC 13, 13th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery, Honolulu, HI, US, Apr 4-7, 2010
Y1  - 2010
SN  - 978-1-617-38848-4
SP  - 665
EP  - 670
PB  - Curran
CY  - Red Hook, NY
ER  - 
TY  - JOUR
A1  - Lettini, Antonio
A1  - Havermann, Marc
A1  - Guidetti, Marco
A1  - Fornaciari, Andrea
T1  - Improved functionalities and energy saving potential on mobile machines combining electronics with flow sharing valve and variable displacement pump
JF  - IFK 7, 7th International Fluid Power Conference, Efficiency through Fluid Power, 7. Internationales Fluidtechnisches Kolloquium, Workshop Proceedings, Vol. 3, Aachen, DE, 22.-24. Mar, 2010
Y1  - 2010
SN  - 978-3-940565-92-1
N1  - IFK, 7, Internationales Fluidtechnisches Kolloquium, 7., Aachen, DE, 2010-03-22 - 2010-03-24
SP  - 103
EP  - 114
PB  - -
ER  - 
TY  - CHAP
A1  - Havermann, Marc
A1  - Seiler, F.
A1  - Henning, P.
ED  - Dillmann, Andreas
ED  - Heller, Gerd
ED  - Klaas, Michael
ED  - Kreplin, Hans-Peter
ED  - Nitsche, Wolfgang
ED  - Schröder, Wolfgang
T1  - Shock Tunnel Experiments and CFD Simulation of Lateral Jet Interaction in Hypersonic Flows
T2  - New Results in Numerical and Experimental Fluid Mechanics VII; Contributions to the 16th STAB/DGLR Symposium Aachen, Germany 2008
Y1  - 2010
SN  - 9783642142437
U6  - https://doi.org/10.1007/978-3-642-14243-7_45
N1  - Notes on numerical fluid mechanics and multidisciplinary design 112
SP  - 365
EP  - 372
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Christen, Marc
A1  - Bartelt, Perry
A1  - Kowalski, Julia
T1  - Back calculation of the In den Arelen avalanche with RAMMS: Interpretation of model results
JF  - Annals of Glaciology
N2  - Two- and three-dimensional avalanche dynamics models are being increasingly used in hazard-mitigation studies. These models can provide improved and more accurate results for hazard mapping than the simple one-dimensional models presently used in practice. However, two- and three-dimensional models generate an extensive amount of output data, making the interpretation of simulation results more difficult. To perform a simulation in three-dimensional terrain, numerical models require a digital elevation model, specification of avalanche release areas (spatial extent and volume), selection of solution methods, finding an adequate calculation resolution and, finally, the choice of friction parameters. In this paper, the importance and difficulty of correctly setting up and analysing the results of a numerical avalanche dynamics simulation is discussed. We apply the two-dimensional simulation program RAMMS to the 1968 extreme avalanche event In den Arelen. We show the effect of model input variations on simulation results and the dangers and complexities in their interpretation.
KW  - avalanche
Y1  - 2010
SN  - 1727-5644
U6  - https://doi.org/10.3189/172756410791386553
VL  - 51
IS  - 54
SP  - 161
EP  - 168
PB  - Cambridge University Press
CY  - Cambridge
ER  - 
TY  - JOUR
A1  - Christen, Marc
A1  - Kowalski, Julia
A1  - Bartelt, Perry
T1  - RAMMS: Numerical simulation of dense snow avalanches in three-dimensional terrain
JF  - Cold Regions Science and Technology
N2  - Numerical avalanche dynamics models have become an essential part of snow engineering. Coupled with field observations and historical records, they are especially helpful in understanding avalanche flow in complex terrain. However, their application poses several new challenges to avalanche engineers. A detailed understanding of the avalanche phenomena is required to construct hazard scenarios which involve the careful specification of initial conditions (release zone location and dimensions) and definition of appropriate friction parameters. The interpretation of simulation results requires an understanding of the numerical solution schemes and easy to use visualization tools. We discuss these problems by presenting the computer model RAMMS, which was specially designed by the SLF as a practical tool for avalanche engineers. RAMMS solves the depth-averaged equations governing avalanche flow with accurate second-order numerical solution schemes. The model allows the specification of multiple release zones in three-dimensional terrain. Snow cover entrainment is considered. Furthermore, two different flow rheologies can be applied: the standard Voellmy–Salm (VS) approach or a random kinetic energy (RKE) model, which accounts for the random motion and inelastic interaction between snow granules. We present the governing differential equations, highlight some of the input and output features of RAMMS and then apply the models with entrainment to simulate two well-documented avalanche events recorded at the Vallée de la Sionne test site.
KW  - RAMMS
KW  - snow
KW  - avalanche
Y1  - 2010
U6  - https://doi.org/10.1016/j.coldregions.2010.04.005
SN  - 1872-7441
VL  - 63
IS  - 1-2
SP  - 1
EP  - 14
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Kapoor, Hrshi
A1  - Boller, Christian
A1  - Giljohann, Sebastian
A1  - Braun, Carsten
T1  - Strategies for structural health monitoring implementation potential assessment in aircraft operational life extension considerations
T2  - 2nd International Symposium on NDT in Aerospace : November 22-24, 2010 Hamburg, Germany
Y1  - 2010
SN  - 978-3-940283-28-3
PB  - Dt. Gesellschaft für Zerstörungsfreie Prüfung
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Kapoor, Hrshi
A1  - Braun, Carsten
A1  - Boller, Christian
ED  - Casciati, Fabio
T1  - Modelling and optimisation of maintenance intervals to realize structural health monitoring applications on aircraft
T2  - Structural health monitoring 2010 : proceedings of the Fifth European Workshop on Structural Health Monitoring held at Sorrento, Naples, Italy, June 28 - July 4, 2010 ; [EWSHM]
Y1  - 2010
SN  - 978-1-60595-024-2
SP  - 55
EP  - 63
PB  - DEStech Publ.
CY  - Lancaster, Pa.
ER  - 
TY  - CHAP
A1  - Reimer, Lars
A1  - Braun, Carsten
A1  - Wellmer, Georg
A1  - Behr, Marek
A1  - Ballmann, Josef
T1  - Development of a modular method for computational aero-structural analysis of aircraft
T2  - Summary of flow modulation and fluid-structure interaction findings. Results of the Collaborative Research Center SFB 401 at the RWTH Aachen University, Aachen, Germany, 1997-2008 / ed.: Wolfgang Schröder. Notes on numerical fluid mechanics and multidisciplinary design. Vol. 109
Y1  - 2010
SN  - 978-3-642-04087-0
SP  - 205
EP  - 238
PB  - Springer
CY  - Berlin
ER  -