@article{EdipSesovButenwegetal.2018, author = {Edip, K. and Sesov, V. and Butenweg, Christoph and Bojadjieva, J.}, title = {Development of coupled numerical model for simulation of multiphase soil}, series = {Computers and Geotechnics}, volume = {96}, journal = {Computers and Geotechnics}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0266-352X}, doi = {10.1016/j.compgeo.2017.08.016}, pages = {118 -- 131}, year = {2018}, abstract = {In this paper, a coupled multiphase model considering both non-linearities of water retention curves and solid state modeling is proposed. The solid displacements and the pressures of both water and air phases are unknowns of the proposed model. The finite element method is used to solve the governing differential equations. The proposed method is demonstrated through simulation of seepage test and partially consolidation problem. Then, implementation of the model is done by using hypoplasticity for the solid phase and analyzing the fully saturated triaxial experiments. In integration of the constitutive law error controlling is improved and comparisons done accordingly. In this work, the advantages and limitations of the numerical model are discussed.}, language = {en} } @article{ZhangValeroBungetal.2018, author = {Zhang, G. and Valero, Daniel and Bung, Daniel Bernhard and Chanson, H.}, title = {On the estimation of free-surface turbulence using ultrasonic sensors}, series = {Flow Measurement and Instrumentation}, volume = {60}, journal = {Flow Measurement and Instrumentation}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0955-5986}, doi = {10.1016/j.flowmeasinst.2018.02.009}, pages = {171 -- 184}, year = {2018}, abstract = {Accurate determination of free-surface dynamics has attracted much research attention during the past decade and has important applications in many environmental and water related areas. In this study, the free-surface dynamics in several turbulent flows commonly found in nature were investigated using a synchronised setup consisting of an ultrasonic sensor and a high-speed video camera. Basic sensor capabilities were examined in dry conditions to allow for a better characterisation of the present sensor model. The ultrasonic sensor was found to adequately reproduce free-surface dynamics up to the second order, especially in two-dimensional scenarios with the most energetic modes in the low frequency range. The sensor frequency response was satisfactory in the sub-20 Hz band, and its signal quality may be further improved by low-pass filtering prior to digitisation. The application of the USS to characterise entrapped air in high-velocity flows is also discussed.}, language = {en} } @article{BongaertsEsserLorbachetal.2011, author = {Bongaerts, Johannes and Esser, Simon and Lorbach, Volker and Al-Momani, L{\´o}ay and M{\"u}ller, Michael A. and Franke, Dirk and Grondal, Christoph and Kurutsch, Anja and Bujnicki, Robert and Takors, Ralf and Raeven, Leon and Wubbolts, Marcel and Bovenberg, Roel and Nieger, Martin and Sch{\"u}rmann, Melanie and Trachtmann, Natalie and Kozak, Stefan and Sprenger, Georg A. and M{\"u}ller, Michael}, title = {Diversity-oriented production of metabolites derived from chorismate and their use in organic synthesis}, series = {Angewandte Chemie International Edition}, volume = {Vol. 50}, journal = {Angewandte Chemie International Edition}, number = {Iss. 34}, publisher = {Wiley}, address = {Weinheim}, issn = {1521-3773 (E-Journal); 0570-0833 (Print); 1433-7851 (Print)}, pages = {7781 -- 7786}, year = {2011}, language = {en} } @article{MarinkovicButenweg2022, author = {Marinkovic, Marko and Butenweg, Christoph}, title = {Numerical analysis of the in-plane behaviour of decoupled masonry infilled RC frames}, series = {Engineering Structures}, volume = {272}, journal = {Engineering Structures}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0141-0296}, doi = {10.1016/j.engstruct.2022.114959}, pages = {18 Seiten}, year = {2022}, abstract = {Damage of reinforced concrete (RC) frames with masonry infill walls has been observed after many earthquakes. Brittle behaviour of the masonry infills in combination with the ductile behaviour of the RC frames makes infill walls prone to damage during earthquakes. Interstory deformations lead to an interaction between the infill and the RC frame, which affects the structural response. The result of this interaction is significant damage to the infill wall and sometimes to the surrounding structural system too. In most design codes, infill walls are considered as non-structural elements and neglected in the design process, because taking into account the infills and considering the interaction between frame and infill in software packages can be complicated and impractical. A good way to avoid negative aspects arising from this behavior is to ensure no or low-interaction of the frame and infill wall, for instance by decoupling the infill from the frame. This paper presents the numerical study performed to investigate new connection system called INODIS (Innovative Decoupled Infill System) for decoupling infill walls from surrounding frame with the aim to postpone infill activation to high interstory drifts thus reducing infill/frame interaction and minimizing damage to both infills and frames. The experimental results are first used for calibration and validation of the numerical model, which is then employed for investigating the influence of the material parameters as well as infill's and frame's geometry on the in-plane behaviour of the infilled frames with the INODIS system. For all the investigated situations, simulation results show significant improvements in behaviour for decoupled infilled RC frames in comparison to the traditionally infilled frames.}, language = {en} } @article{BungErpicumTullis2020, author = {Bung, Daniel Bernhard and Erpicum, S{\´e}bastien and Tullis, Blanke P.}, title = {Advances in hydraulic structures engineering}, series = {Journal of Hydraulic Engineering}, volume = {147}, journal = {Journal of Hydraulic Engineering}, number = {1}, publisher = {ASCE}, address = {Reston, Va.}, issn = {0733-9429 (Druckausgabe)}, doi = {10.1061/(ASCE)HY.1943-7900.0001851}, pages = {1 Seite}, year = {2020}, language = {en} } @article{PeloniDachwaldCeriotti2017, author = {Peloni, Alessandro and Dachwald, Bernd and Ceriotti, Matteo}, title = {Multiple near-earth asteroid rendezvous mission: Solar-sailing options}, series = {Advances in Space Research}, journal = {Advances in Space Research}, number = {In Press, Corrected Proof}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0273-1177}, doi = {10.1016/j.asr.2017.10.017}, year = {2017}, language = {en} } @article{ValeroChansonBung2019, author = {Valero, Daniel and Chanson, Hubert and Bung, Daniel Bernhard}, title = {Robust estimators for turbulence properties assessment}, pages = {1 -- 24}, year = {2019}, language = {en} } @article{DachwaldSeboldtLoebetal.2008, author = {Dachwald, Bernd and Seboldt, Wolfgang and Loeb, H. W. and Schartner, Karl-Heinz}, title = {Main Belt Asteroid Sample Return Mission Using Solar Electric Propulsion}, series = {Acta Astronautica. 63 (2008), H. 1-4}, journal = {Acta Astronautica. 63 (2008), H. 1-4}, isbn = {0094-5765}, pages = {91 -- 101}, year = {2008}, language = {en} } @article{KezerashviliDachwald2021, author = {Kezerashvili, Roman Ya and Dachwald, Bernd}, title = {Preface: Solar sailing: Concepts, technology, and missions II}, series = {Advances in Space Research}, volume = {67}, journal = {Advances in Space Research}, number = {9}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0273-1177}, doi = {10.1016/j.asr.2021.01.037}, pages = {2559 -- 2560}, year = {2021}, language = {en} } @article{HagenkampBlankeDoering2021, author = {Hagenkamp, Markus and Blanke, Tobias and D{\"o}ring, Bernd}, title = {Thermoelectric building temperature control: a potential assessment}, series = {International Journal of Energy and Environmental Engineering}, volume = {13}, journal = {International Journal of Energy and Environmental Engineering}, publisher = {Springer}, address = {Berlin}, doi = {10.1007/s40095-021-00424-x}, pages = {241 -- 254}, year = {2021}, abstract = {This study focuses on thermoelectric elements (TEE) as an alternative for room temperature control. TEE are semi-conductor devices that can provide heating and cooling via a heat pump effect without direct noise emissions and no refrigerant use. An efficiency evaluation of the optimal operating mode is carried out for different numbers of TEE, ambient temperatures, and heating loads. The influence of an additional heat recovery unit on system efficiency and an unevenly distributed heating demand are examined. The results show that TEE can provide heat at a coefficient of performance (COP) greater than one especially for small heating demands and high ambient temperatures. The efficiency increases with the number of elements in the system and is subject to economies of scale. The best COP exceeds six at optimal operating conditions. An additional heat recovery unit proves beneficial for low ambient temperatures and systems with few TEE. It makes COPs above one possible at ambient temperatures below 0 ∘C. The effect increases efficiency by maximal 0.81 (from 1.90 to 2.71) at ambient temperature 5 K below room temperature and heating demand Q˙h=100W but is subject to diseconomies of scale. Thermoelectric technology is a valuable option for electricity-based heat supply and can provide cooling and ventilation functions. A careful system design as well as an additional heat recovery unit significantly benefits the performance. This makes TEE superior to direct current heating systems and competitive to heat pumps for small scale applications with focus on avoiding noise and harmful refrigerants.}, language = {en} }