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 - Kleine, Harald A1 - Kallweit, Stephan A1 - Michaux, Frank A1 - Havermann, Marc A1 - Olivier, Herbert T1 - PIV Measurement of Shock Wave Diffraction T2 - 18th International Symposium on Applications of Laser Techniques to Fluid Mechanics, 2016, Lissabon Y1 - 2016 SP - 1 EP - 14 ER - TY - CHAP A1 - Knobloch, V. A1 - Kowalski, Julia A1 - Bösiger, P. A1 - Kozerke, S. T1 - Probabilistic Streamline Estimation from Accelerated Fourier Velocity Encoded Measurements T2 - Proceedings of the 19th ISMRM International Society for Magnetic Resonance in Medicine Y1 - 2011 N1 - ISMRM 19th Annual Meeting & Exhibition in Montréal, Québec, Canada SP - 1215 EP - 1215 ER - TY - CHAP A1 - Kohlberger, David-Sharif A1 - Wild, Dominik A1 - Kasper, Stefan A1 - Czupalla, Markus T1 - Modeling and analyses of a thermal passively stabilized LEO/GEO star tracker with embedded phase change material applying the Infused Thermal Solutions (ITS) method T2 - ICES202: Satellite, Payload, and Instrument Thermal Control N2 - Phase change materials offer a way of storing excess heat and releasing it when it is needed. They can be utilized as a method to control thermal behavior without the need for additional energy. This work focuses on exploring the potential of using phase change materials to passively control the thermal behavior of a star tracker by infusing it with a fitting phase change material. Based on the numerical model of the star trackers thermal behavior using ESATAN-TMS without implemented phase change material, a fitting phase change material for selected orbits is chosen and implemented in the thermal model. The altered thermal behavior of the numerical model after the implementation is analyzed for different amounts of the chosen phase change materials using an ESATAN-based subroutine developed by the FH Aachen. The PCM-modelling-subroutine is explained in the paper ICES-2021-110. The results show that an increasing amount of phase change material increasingly damps temperature oscillations. Using an integral part structure some of the mass increase can be compensated. KW - passive thermal control KW - PCM KW - star tracker KW - Infused Thermal Solutions KW - GEO KW - LEO Y1 - 2021 N1 - 50th International Conference on Environmental Systems, 12-15 July 2021, held virtually PB - Texas Tech University CY - Lubbock, Tex. ER - TY - CHAP A1 - Konstantinidis, K. A1 - Dachwald, Bernd A1 - Ohndorf, A. A1 - Dykta, P. A1 - Voigt, K. A1 - Förstner, R. T1 - Enceladus explorer (ENEX): A lander mission to probe subglacial water pockets on Saturn's moon enceladus for life T2 - 64th International Astronautical Congress 2013 (IAC 2013) : Beijing, China, 23 - 27 September 2013. (Proceedings of the International Astronautical Congress, IAC ; 2) Y1 - 2013 SN - 978-1-62993-909-4 SP - 1340 EP - 1350 PB - Curran CY - Red Hook, NY ER - TY - CHAP A1 - Konstantinidis, K. A1 - Kowalski, Julia A1 - Martinez, C. F. A1 - Dachwald, Bernd A1 - Ewerhart, D. A1 - Förstner, R. T1 - Some necessary technologies for in-situ astrobiology on enceladus T2 - Proceedings of the International Astronautical Congress Y1 - 2015 SN - 978-151081893-4 N1 - 6th International Astronautical Congress 2015: Space - The Gateway for Mankind's Future, IAC 2015; Jerusalem; Israel; 12 October 2015 through 16 October 2015 SP - 1354 EP - 1372 ER - TY - CHAP A1 - Korsch, Helge A1 - Dafnis, Athanasios A1 - Reimerdes, Hans-Günther A1 - Braun, Carsten A1 - Ballmann, Josef T1 - Dynamic qualification of the HIRENASD elastic wing model T2 - Motto: Luft- und Raumfahrt: Lehre, Forschung, Industrie - gemeinsam innovativ. Deutscher Luft- und Raumfahrtkongress 2006 : Braunschweig, 06. bis 09. November 2006. Jahrbuch / Deutsche Gesellschaft für Luft- und Raumfahrt. 2006 Y1 - 2006 SP - 1441 EP - 1450 PB - Dt. Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth (DGLR) CY - Bonn ER - TY - CHAP A1 - Kowalski, Julia T1 - Numerical Debris Flow Simulation T2 - Schweizer Numerik Kolloquium : Book of Abstracts 12. April 2006 Y1 - 2006 ER - TY - CHAP A1 - Kowalski, Julia A1 - Bartelt, Perry A1 - McElwaine, J. T1 - Two-phase debris flow modeling T2 - Geophysical Research Abstracts Y1 - 2007 N1 - A-08119 ER - TY - CHAP A1 - Kowalski, Julia A1 - Bugnion, Louis T1 - An extended shallow flow theory for natural debris flows Y1 - 2009 N1 - 2009 Portland GSA Annual Meeting (18-21 October 2009); Geological Society of America VL - 41 IS - 7 SP - 609 EP - 609 ER - TY - CHAP A1 - Kowalski, Julia A1 - McArdell, B. W. A1 - Bartelt, Perry T1 - A comparison of two approaches to modeling multiphase gravity currents T2 - Geophysical Research Abstracts Y1 - 2006 N1 - A-08738 VL - 8 ER - TY - CHAP A1 - Kowalski, Julia A1 - McElwaine, J. T1 - Two-phase debris flow modeling T2 - Geophysical Research Abstracts Y1 - 2008 N1 - A-01048 ER - TY - CHAP A1 - Kreyer, Jörg A1 - Esch, Thomas T1 - Simulation Tool for Predictive Control Strategies for an ORCSystem in Heavy Duty Vehicles T2 - European GT Conference 2017 N2 - Scientific questions - How can a non-stationary heat offering in the commercial vehicle be used to reduce fuel consumption? - Which potentials offer route and environmental information among with predicted speed and load trajectories to increase the efficiency of a ORC-System? Methods - Desktop bound holistic simulation model for a heavy duty truck incl. an ORC System - Prediction of massflows, temperatures and mixture quality (AFR) of exhaust gas Y1 - 2017 N1 - European GT Conference 2017, 9.-10. Oktober 2017, Frankfurt a.M. ER - TY - CHAP A1 - Kreyer, Jörg A1 - Müller, Marvin A1 - Esch, Thomas T1 - A Map-Based Model for the Determination of Fuel Consumption for Internal Combustion Engines as a Function of Flight Altitude N2 - In addition to very high safety and reliability requirements, the design of internal combustion engines (ICE) in aviation focuses on economic efficiency. The objective must be to design the aircraft powertrain optimized for a specific flight mission with respect to fuel consumption and specific engine power. Against this background, expert tools provide valuable decision-making assistance for the customer. In this paper, a mathematical calculation model for the fuel consumption of aircraft ICE is presented. This model enables the derivation of fuel consumption maps for different engine configurations. Depending on the flight conditions and based on these maps, the current and the integrated fuel consumption for freely definable flight emissions is calculated. For that purpose, an interpolation method is used, that has been optimized for accuracy and calculation time. The mission boundary conditions flight altitude and power requirement of the ICE form the basis for this calculation. The mathematical fuel consumption model is embedded in a parent program. This parent program presents the simulated fuel consumption by means of an example flight mission for a representative airplane. The focus of the work is therefore on reproducing exact consumption data for flight operations. By use of the empirical approaches according to Gagg-Farrar [1] the power and fuel consumption as a function of the flight altitude are determined. To substantiate this approaches, a 1-D ICE model based on the multi-physical simulation tool GT-Suite® has been created. This 1-D engine model offers the possibility to analyze the filling and gas change processes, the internal combustion as well as heat and friction losses for an ICE under altitude environmental conditions. Performance measurements on a dynamometer at sea level for a naturally aspirated ICE with a displacement of 1211 ccm used in an aviation aircraft has been done to validate the 1-D ICE model. To check the plausibility of the empirical approaches with respect to the fuel consumption and performance adjustment for the flight altitude an analysis of the ICE efficiency chain of the 1-D engine model is done. In addition, a comparison of literature and manufacturer data with the simulation results is presented. Y1 - 2020 U6 - https://doi.org/10.25967/490162 N1 - 68. Deutscher Luft- und Raumfahrtkongress 30.09.-02.10.2019, Darmstadt PB - DGLR CY - Bonn ER - TY - CHAP A1 - Kroniger, Daniel A1 - Horikawa, Atsushi A1 - Funke, Harald A1 - Pfäffle, Franziska T1 - Numerical investigation of micromix hydrogen flames at different combustor pressure levels T2 - The Proceedings of the International Conference on Power Engineering (ICOPE) N2 - This study investigates the influence of pressure on the temperature distribution of the micromix (MMX) hydrogen flame and the NOx emissions. A steady computational fluid dynamic (CFD) analysis is performed by simulating a reactive flow with a detailed chemical reaction model. The numerical analysis is validated based on experimental investigations. A quantitative correlation is parametrized based on the numerical results. We find, that the flame initiation point shifts with increasing pressure from anchoring behind a downstream located bluff body towards anchoring upstream at the hydrogen jet. The numerical NOx emissions trend regarding to a variation of pressure is in good agreement with the experimental results. The pressure has an impact on both, the residence time within the maximum temperature region and on the peak temperature itself. In conclusion, the numerical model proved to be adequate for future prototype design exploration studies targeting on improving the operating range. KW - Gas turbine combustion KW - Hydrogen KW - NOx emissions KW - Flame temperature KW - Flame residence time Y1 - 2021 U6 - https://doi.org/10.1299/jsmeicope.2021.15.2021-0237 N1 - International Conference on Power Engineering 2021 (ICOPE-2021). October 17 - 21, 2021. Kobe, Japan (Online) ER - TY - CHAP A1 - Kroniger, Daniel A1 - Horikawa, Atsushi A1 - Funke, Harald A1 - Pfäffle, Franziska A1 - Kishimoto, Tsuyoshi A1 - Okada, Koichi T1 - Experimental and numerical investigation on the effect of pressure on micromix hydrogen combustion T2 - Conference Proceedings Turbo Expo: Power for Land, Sea and Air, Volume 3A: Combustion, Fuels, and Emissions N2 - The micromix (MMX) combustion concept is a DLN gas turbine combustion technology designed for high hydrogen content fuels. Multiple non-premixed miniaturized flames based on jet in cross-flow (JICF) are inherently safe against flashback and ensure a stable operation in various operative conditions. The objective of this paper is to investigate the influence of pressure on the micromix flame with focus on the flame initiation point and the NOx emissions. A numerical model based on a steady RANS approach and the Complex Chemistry model with relevant reactions of the GRI 3.0 mechanism is used to predict the reactive flow and NOx emissions at various pressure conditions. Regarding the turbulence-chemical interaction, the Laminar Flame Concept (LFC) and the Eddy Dissipation Concept (EDC) are compared. The numerical results are validated against experimental results that have been acquired at a high pressure test facility for industrial can-type gas turbine combustors with regard to flame initiation and NOx emissions. The numerical approach is adequate to predict the flame initiation point and NOx emission trends. Interestingly, the flame shifts its initiation point during the pressure increase in upstream direction, whereby the flame attachment shifts from anchoring behind a downstream located bluff body towards anchoring directly at the hydrogen jet. The LFC predicts this change and the NOx emissions more accurately than the EDC. The resulting NOx correlation regarding the pressure is similar to a non-premixed type combustion configuration. KW - NOx emissions KW - hydrogen KW - combustor KW - gas turbine Y1 - 2021 U6 - https://doi.org/10.1115/GT2021-58926 N1 - ASME Turbo Expo 2021: Turbomachinery Technical Conference and Exposition, June 7–11, 2021, Virtual, Online. Paper No: GT2021-58926, V03AT04A025 PB - ASME CY - New York, NY ER - TY - CHAP A1 - Lao, B. A1 - Bührig-Polaczek, A. A1 - Röth, Thilo ED - Wielage, Bernhard T1 - Funktionsintegrierte Leichtbaustrukturen in gussintensiver Metall-Hybridbauweise T2 - Verbundwerkstoffe und Werkstoffverbunde: Tagungsband zum 18. Symposium ; 30.03.2011 bis 01.04.2011, Chemnitz Y1 - 2011 SN - 978-3-00-033801-4 N1 - Schriftenreihe Werkstoffe und werkstofftechnische Anwendungen ; 41 SP - 413 EP - 421 PB - Eigenverlag CY - Chemnitz ER - TY - CHAP A1 - Loeb, Horst W. A1 - Schartner, Karl-Heinz A1 - Dachwald, Bernd A1 - Ohndorf, Andreas A1 - Seboldt, Wolfgang T1 - An Interstellar – Heliopause mission using a combination of solar/radioisotope electric propulsion T2 - Presented at the 32nd International Electric Propulsion Conference N2 - There is common agreement within the scientific community that in order to understand our local galactic environment it will be necessary to send a spacecraft into the region beyond the solar wind termination shock. Considering distances of 200 AU for a new mission, one needs a spacecraft travelling at a speed of close to 10 AU/yr in order to keep the mission duration in the range of less than 25 yrs, a transfer time postulated by ESA.Two propulsion options for the mission have been proposed and discussed so far: the solar sail propulsion and the ballistic/radioisotope electric propulsion. As a further alternative, we here investigate a combination of solar-electric propulsion and radioisotope-electric propulsion. The solar-electric propulsion stage consists of six 22 cm diameter “RIT-22”ion thrusters working with a high specific impulse of 7377 s corresponding to a positive grid voltage of 5 kV. Solar power of 53 kW BOM is provided by a light-weight solar array. The REP-stage consists of four space-proven 10 cm diameter “RIT-10” ion thrusters that will be operating one after the other for 9 yrs in total. Four advanced radioisotope generators provide 648 W at BOM. The scientific instrument package is oriented at earlier studies. For its mass and electric power requirement 35 kg and 35 W are assessed, respectively. Optimized trajectory calculations, treated in a separate contribution, are based on our “InTrance” method.The program yields a burn out of the REP stage in a distance of 79.6 AU for a usage of 154 kg of Xe propellant. With a C3 = 45,1 (km/s)2 a heliocentric probe velocity of 10 AU/yr is reached at this distance, provided a close Jupiter gravity assist adds a velocity increment of 2.7 AU/yr. A transfer time of 23.8 yrs results for this scenario requiring about 450 kg Xe for the SEP stage, jettisoned at 3 AU. We interpret the SEP/REP propulsion as a competing alternative to solar sail and ballistic/REP propulsion. Omiting a Jupiter fly-by even allows more launch flexibility, leaving the mission duration in the range of the ESA specification. Y1 - 2011 N1 - 32nd International Electric Propulsion Conference, 11-15 September. Wiesbaden, Germany SP - 1 EP - 7 ER - TY - CHAP A1 - Loeb, Horst W. A1 - Schartner, Karl-Heinz A1 - Seboldt, Wolfgang A1 - Dachwald, Bernd A1 - Streppel, Joern A1 - Meusemann, Hans A1 - Schülke, Peter T1 - SEP for a lander mission to the jovian moon europa T2 - 57th International Astronautical Congress N2 - Under DLR-contract, Giessen University and DLR Cologne are studying solar-electric propulsion missions (SEP) to the outer regions of the solar system. The most challenging reference mission concerns the transport of a 1.35-tons chemical lander spacecraft into an 80-RJ circular orbit around Jupiter, which would enable to place a 375 kg lander with 50 kg of scientific instruments on the surface of the icy moon "Europa". Thorough analyses show that the best solution in terms of SEP launch mass times thrusting time would be a two-stage EP module and a triple-junction solar array with concentrators which would be deployed step by step. Mission performance optimizations suggest to propel the spacecraft in the first EP stage by 6 gridded ion thrusters, running at 4.0 kV of beam voltage, which would save launch mass, and in the second stage by 4 thrusters with 1.25 to 1.5 kV of positive high voltage saving thrusting time. In this way, the launch mass of the spacecraft would be kept within 5.3 tons. Without a launcher's C3 and interplanetary gravity assists, Jupiter might be reached within about 4 yrs. The spiraling-down into the parking orbit would need another 1.8 yrs. This "large mission" can be scaled down to a smaller one, e.g., by halving all masses, the solar array power, and the number of thrusters. Due to their reliability, long lifetime and easy control, RIT-22 engines have been chosen for mission analysis. Based on precise tests, the thruster performance has been modeled. Y1 - 2006 U6 - https://doi.org/10.2514/6.IAC-06-C4.4.04 N1 - 57th International Astronautical Congress, 02 October 2006 - 06 October 2006, Valencia, Spain. SP - 1 EP - 12 ER - TY - CHAP A1 - Loeb, Horst Wolfgang A1 - Schartner, Karl-Heinz A1 - Dachwald, Bernd A1 - Seboldt, Wolfgang T1 - SEP-Sample return from a main belt asteroid T2 - 30th International Electric Propulsion Conference N2 - By DLR-contact, sample return missions to the large main-belt asteroid “19, Fortuna” have been studied. The mission scenario has been based on three ion thrusters of the RIT-22 model, which is presently under space qualification, and on solar arrays equipped with triple-junction GaAs solar cells. After having designed the spacecraft, the orbit-to-orbit trajectories for both, a one-way SEP mission with a chemical sample return and an all-SEP return mission, have been optimized using a combination of artificial neural networks with evolutionary algorithms. Additionally, body-to-body trajectories have been investigated within a launch period between 2012 and 2015. For orbit-to-orbit calculation, the launch masses of the hybrid mission and of the all-SEP mission resulted in 2.05 tons and 1.56 tons, respectively, including a scientific payload of 246 kg. For the related transfer durations 4.14 yrs and 4.62 yrs were obtained. Finally, a comparison between the mission scenarios based on SEP and on NEP have been carried out favouring clearly SEP. Y1 - 2007 SP - 1 EP - 11 ER -