@inproceedings{MeierJongmannsEgbers, author = {Meier, Martin and Jongmanns, Marcel and Egbers, Christoph}, title = {Investigations on thermal electro-hydrodynamic convection in a cylindrical gap}, series = {Experimentelle Str{\"o}mungsmechanik, 24. Fachtagung 6.-8. September 2016 Cottbus}, booktitle = {Experimentelle Str{\"o}mungsmechanik, 24. Fachtagung 6.-8. September 2016 Cottbus}, editor = {Egbers, Christoph}, publisher = {German Association for Laser Anemometry GALA e.V.}, address = {Karlsruhe}, isbn = {978-3-9816764-2-6}, pages = {S. 39}, language = {en} } @inproceedings{JongmannsSeeligEgbersetal., author = {Jongmanns, Marcel and Seelig, Torsten and Egbers, Christoph and Meier, Martin and Meyer, Antoine and Crumeyrolle, Olivier and Mutabazi, Innocent}, title = {Thermoelectrohydrodynamic experiments in a cylindrical gap}, series = {Book of abstracts, School ISTROF 2016, Instabilities and Turbulence in Strato-Rotational Flows, July 11-13th, 2016, Le Havre}, booktitle = {Book of abstracts, School ISTROF 2016, Instabilities and Turbulence in Strato-Rotational Flows, July 11-13th, 2016, Le Havre}, language = {en} } @misc{MeyerJongmannsMeieretal., author = {Meyer, Antoine and Jongmanns, Marcel and Meier, Martin and Egbers, Christoph and Mutabazi, Innocent}, title = {Thermal convection in a cylindrical annulus under a combined effect of the radial and vertical gravity}, series = {Comptes Rendus M{\´e}canique}, volume = {345}, journal = {Comptes Rendus M{\´e}canique}, number = {1}, issn = {1631-0721}, pages = {11 -- 20}, language = {en} } @inproceedings{MeierJongmannsRuoffetal., author = {Meier, Martin and Jongmanns, Marcel and Ruoff, Vilko and Egbers, Christoph and Meyer, Antoine and Mutabazi, Innocent}, title = {Flow pattern and heat transfer in a cylindrical annulus under 1g and low-g conditions: Experiments}, series = {Joint Conference ISPS-7 and ELGRA-25 October, 2-6 2017, Juan-les-Pins, France, Abstract book}, booktitle = {Joint Conference ISPS-7 and ELGRA-25 October, 2-6 2017, Juan-les-Pins, France, Abstract book}, pages = {S. 48}, language = {en} } @inproceedings{MeyerCrumeyrolleMutabazietal., author = {Meyer, Antoine and Crumeyrolle, Olivier and Mutabazi, Innocent and Meier, Martin and Jongmanns, Marcel and Ruoff, Vilko and Seelig, Torsten and Egbers, Christoph}, title = {Flow pattern and heat transfer in a cylindrical annulus under 1g and low-g conditions: theory and simulation}, series = {Joint Conference ISPS-7 and ELGRA-25 October, 2-6 2017, Juan-les-Pins, France, Abstract book}, booktitle = {Joint Conference ISPS-7 and ELGRA-25 October, 2-6 2017, Juan-les-Pins, France, Abstract book}, pages = {S. 48}, language = {en} } @inproceedings{SeeligJongmannsMeyeretal., author = {Seelig, Torsten and Jongmanns, Marcel and Meyer, Antoine and Meier, Martin and Egbers, Christoph}, title = {Onset of dielectrophoretic force-driven convection in annular geometry under Earth's gravity}, series = {20th International Couette-Taylor Workshop, 11-13 July 2018, Marseille, France, Book of abstracts}, booktitle = {20th International Couette-Taylor Workshop, 11-13 July 2018, Marseille, France, Book of abstracts}, pages = {2}, language = {en} } @inproceedings{MeyerJongmannsMeieretal., author = {Meyer, Antoine and Jongmanns, Marcel and Meier, Martin and Seelig, Torsten and Kang, Changwoo and Mutabazi, Innocent and Egbers, Christoph}, title = {Experiments on thermoelectric convection induced in a cylindrical annulus under microgravity conditions}, series = {20th International Couette-Taylor Workshop, 11-13 July 2018, Marseille, France, Book of abstracts}, booktitle = {20th International Couette-Taylor Workshop, 11-13 July 2018, Marseille, France, Book of abstracts}, pages = {2}, language = {en} } @inproceedings{MutabaziKangMeyeretal., author = {Mutabazi, Innocent and Kang, Changwoo and Meyer, Antoine and Jongmanns, Marcel and Meier, Martin and Egbers, Christoph}, title = {Thermoelectric convection in dielectric liquids in a cylindrical annulus}, series = {International Conference on Rayleigh B{\´e}nard Turbulence, May 14-18, 2018, Enschede, NL}, booktitle = {International Conference on Rayleigh B{\´e}nard Turbulence, May 14-18, 2018, Enschede, NL}, pages = {S. 83}, language = {en} } @misc{MeierJongmannsMeyeretal., author = {Meier, Martin and Jongmanns, Marcel and Meyer, Antoine and Seelig, Torsten and Egbers, Christoph and Mutabazi, Innocent}, title = {Flow Pattern and Heat Transfer in a Cylindrical Annulus Under 1 g and Low-g Conditions: Experiments}, series = {Microgravity science and technology : international journal for microgravity research and applications}, volume = {30}, journal = {Microgravity science and technology : international journal for microgravity research and applications}, number = {5}, issn = {1875-0494}, doi = {10.1007/s12217-018-9649-y}, pages = {699 -- 712}, language = {en} } @misc{MeyerCrumeyrolleMutabazietal., author = {Meyer, Antoine and Crumeyrolle, Olivier and Mutabazi, Innocent and Meier, Martin and Jongmanns, Marcel and Renoult, Marie-Charlotte and Seelig, Torsten and Egbers, Christoph}, title = {Flow Patterns and Heat Transfer in a Cylindrical Annulus under 1g and low-g Conditions: Theory and Simulation}, series = {Microgravity Science and Technology}, volume = {30}, journal = {Microgravity Science and Technology}, number = {5}, issn = {0938-0108}, doi = {10.1007/s12217-018-9636-3}, pages = {653 -- 662}, language = {en} } @inproceedings{JongmannsMeierMeyeretal., author = {Jongmanns, Marcel and Meier, Martin and Meyer, Antoine and Egbers, Christoph}, title = {Bestimmung von Str{\"o}mungsmustern in einem Zylinderspalt mit radialem elektrischen Kraftfeld unter Schwerelosigkeit}, series = {26. GALA - Fachtagung Experimentelle Str{\"o}mungsmechanik, 4. - 6. September 2018, Rostock}, booktitle = {26. GALA - Fachtagung Experimentelle Str{\"o}mungsmechanik, 4. - 6. September 2018, Rostock}, publisher = {Deutsche Gesellschaft f{\"u}r Laser-Anemometrie}, address = {Karlsruhe}, isbn = {978-3-9816764-5-7}, pages = {S. 15}, language = {de} } @inproceedings{MeierEgbersMutabazietal., author = {Meier, Martin and Egbers, Christoph and Mutabazi, Innocent and Meyer, Antoine and Seelig, Torsten and Jongmanns, Marcel}, title = {Enhanced Heat transfer in a cylindrical annulus under 1g and low-g conditions}, series = {69th International Astronautical Congress, 1 - 5 October 2018, Bremen, Germany}, booktitle = {69th International Astronautical Congress, 1 - 5 October 2018, Bremen, Germany}, pages = {1}, language = {en} } @inproceedings{JongmannsMeyerMeieretal., author = {Jongmanns, Marcel and Meyer, Antoine and Meier, Martin and Kang, Changwoo and Mutabazi, Innocent and Egbers, Christoph}, title = {Experiments on thermoelectric convection in dielectric liquids in a cylindrical annulus under parabolic flight conditions}, series = {Abstract booklet for the International Conference on Rayleigh B{\´e}nard Turbulence, May 14-18, 2018, Enschede, NL}, booktitle = {Abstract booklet for the International Conference on Rayleigh B{\´e}nard Turbulence, May 14-18, 2018, Enschede, NL}, pages = {S. 20}, language = {en} } @misc{SeeligMeyerGerstneretal., author = {Seelig, Torsten and Meyer, Antoine and Gerstner, Philipp and Meier, Martin and Jongmanns, Marcel and Baumann, Martin and Heuveline, Vincent and Egbers, Christoph}, title = {Dielectrophoretic force-driven convection in annular geometry under Earth's gravity}, series = {International Journal of Heat and Mass Transfer}, volume = {139}, journal = {International Journal of Heat and Mass Transfer}, issn = {0017-9310}, doi = {10.1016/j.ijheatmasstransfer.2019.04.068}, pages = {386 -- 398}, language = {en} } @misc{MeyerMeierJongmannsetal., author = {Meyer, Antoine and Meier, Martin and Jongmanns, Marcel and Seelig, Torsten and Egbers, Christoph and Mutabazi, Innocent}, title = {Effect of the Initial Conditions on the Growth of Thermoelectric Instabilities During Parabolic}, series = {Microgravity Science and Technology}, volume = {31}, journal = {Microgravity Science and Technology}, number = {5}, issn = {1875-0494}, doi = {10.1007/s12217-019-09755-1}, pages = {715 -- 721}, language = {en} } @phdthesis{Jongmanns, author = {Jongmanns, Marcel}, title = {Flow control of thermal convection using thermo electro hydrodynamic forces in a cylindrical annulus}, publisher = {Cuvillier Verlag}, address = {G{\"o}ttingen}, isbn = {978-3-7369-7044-1}, pages = {x, 160}, language = {en} } @misc{MeyerSeeligGerstneretal., author = {Meyer, Antoine and Seelig, Torsten and Gerstner, Philipp and Kang, Changwoo and Meier, Martin and Jongmanns, Marcel and Baumann, Martin and Mutabazi, Innocent and Heuveline, Vincent and Egbers, Christoph}, title = {Thermo-electro-hydrodynamic instability of a dielectric fluid in a vertical cylindrical annulus: Earth's gravity and weightless conditions}, series = {LIA-ISTROF workshop 2019 Instabilities and Turbulence in Stratified Rotational Flows Cottbus, 19th-20th June 2019 Brandenburg}, journal = {LIA-ISTROF workshop 2019 Instabilities and Turbulence in Stratified Rotational Flows Cottbus, 19th-20th June 2019 Brandenburg}, address = {Cottbus}, pages = {1}, language = {en} } @misc{MeyerSeeligGerstneretal., author = {Meyer, Antoine and Seelig, Torsten and Gerstner, Philipp and Kang, Changwoo and Meier, Martin and Jongmanns, Marcel and Baumann, Martin and Mutabazi, Innocent and Heuveline, Vincent and Egbers, Christoph}, title = {Thermoelectric instability in a vertical cylindrical annulus}, series = {8th International Symposium on Bifurcations and Instabilities in Fluid Dynamics (BIFD), 16-19 July, 2019, University of Limerick, Ireland}, journal = {8th International Symposium on Bifurcations and Instabilities in Fluid Dynamics (BIFD), 16-19 July, 2019, University of Limerick, Ireland}, address = {Limerick}, pages = {1}, language = {en} } @misc{SuawaFogouMeiselJongmannsetal., author = {Suawa Fogou, Priscile and Meisel, Tenia and Jongmanns, Marcel and H{\"u}bner, Michael and Reichenbach, Marc}, title = {Modeling and Fault Detection of Brushless Direct Current Motor by Deep Learning Sensor Data Fusion}, series = {Sensors}, volume = {22}, journal = {Sensors}, number = {9}, issn = {1424-8220}, doi = {10.3390/s22093516}, pages = {17}, language = {en} } @misc{MonsalveGuaracaoMelnikovStolzetal., author = {Monsalve Guaracao, Jorge Mario and Melnikov, Anton and Stolz, Michael and Mrosk, Andreas and Jongmanns, Marcel and Wall, Franziska and Langa, Sergiu and Marica-Bercu, Ioana and Br{\"a}ndel, Tim and Kircher, Marco and Schenk, Hermann A. G. and Kaiser, Bert and Schenk, Harald}, title = {Proof of concept of an air-coupled electrostatic ultrasonic transducer based on lateral motion}, series = {Sensors and Actuators A: Physical}, volume = {Vol. 345}, journal = {Sensors and Actuators A: Physical}, issn = {1873-3069}, doi = {10.1016/j.sna.2022.113813}, abstract = {An alternative implementation of an electrostatic MUT (Micromachined Ultrasonic Transducer), relying on multiple beams that displace along the chip's surface instead of a single membrane displacing perpendicular to it, is presented in this work. With this approach, a design requiring a low bias voltage (24 V) and occupying a small area (3.3×3.3 mm², 2D/λ≈0.77) was shown to generate a sound pressure level of 82 dB (re. 20 µPa-rms) at 40 kHz and a distance of 8.9 cm. The high level of damping allows this transducer to operate in a wide frequency range (35-63 kHz). The operation of this device as an ultrasonic receiver was also proven. An implementation of this transducer as a rangefinder requires a strong reduction in the noise level, particularly coming from radio-frequency interference, in order to increase its detection range.}, language = {en} } @misc{Jongmanns, author = {Jongmanns, Marcel}, title = {Implementation of a hand gesture recognition using ultrasound measurements on a NVIDIA Jetson platform with AI-based evaluation}, publisher = {Berlin}, address = {VDE Verlag}, isbn = {978-3-8007-6204-0}, pages = {S. 694}, language = {en} } @misc{SuawaFogouHalbingerJongmannsetal., author = {Suawa Fogou, Priscile and Halbinger, Anja and Jongmanns, Marcel and Reichenbach, Marc}, title = {Noise-Robust Machine Learning Models for Predictive Maintenance Applications}, series = {IEEE Sensors Journal}, volume = {23}, journal = {IEEE Sensors Journal}, number = {13}, issn = {1558-1748}, doi = {10.1109/JSEN.2023.3273458}, pages = {15081 -- 15092}, abstract = {Predictive maintenance of equipment requires a set of data collected through sensors, from which models will learn behaviors that will allow the automatic detection or prediction of these behaviors. The objective is to anticipate unexpected situations such as sudden equipment stoppages. Industries are noisy environments due to production lines that involve a series of components. As a result, the data will always be obstructed by noise. Noise-robust predictive maintenance models, which include ensemble and deep learning models with and without data fusion, are proposed to enhance the monitoring of industrial equipment. The work reported in this article is based on two components, a milling tool, and a motor, with sound, vibration, and ultrasound data collected in real experiments. Four main tasks were performed, namely the construction of the datasets, the training of the monitoring models without adding artificial noise to the data, the evaluation of the robustness of the previously trained models by injecting several levels of noise into the test data, and the optimization of the models by a proposed noisy training approach. The results show that the models maintain their performances at over 95\% accuracy despite adding noise in the test phase. These performances decrease by only 2\% at a considerable noise level of 15-dB signal-to-noise ratio (SNR). The noisy training method proved to be an optimal solution for improving the noise robustness and accuracy of convolutional deep learning models, whose performance regression of 2\% went from a noise level of 28 to 15 dB like the other models.}, language = {en} } @misc{AssafoLautschSuawaetal., author = {Assafo, Maryam and Lautsch, Martin and Suawa, Priscile Fogou and Jongmanns, Marcel and H{\"u}bner, Michael and Reichenbach, Marc and Brockmann, Carsten and Reinhardt, Denis and Langend{\"o}rfer, Peter}, title = {The ForTune Toolbox: Building Solutions for Condition-Based and Predictive Maintenance Focusing on Retrofitting}, publisher = {VDE Verlag}, address = {Berlin}, isbn = {978-3-8007-6204-0}, pages = {S. 541}, language = {en} } @misc{RuffertJongmannsKaiseretal., author = {Ruffert, Christine and Jongmanns, Marcel and Kaiser, Bert and Langa, Sergiu}, title = {Design and characterization of a silicon MEMS microvalve for proportional flow control based on electrostatic bending actuators}, series = {Microsystem Technologies}, volume = {2024}, journal = {Microsystem Technologies}, issn = {1432-1858}, doi = {10.1007/s00542-024-05684-1}, pages = {8}, abstract = {We designed a MEMS microvalve based on the nanoscopic electrostatic drive (NED) technology (Nat Commun 6:10078, 2015). NED actuators, electrostatically controlled bending beams, are implemented in a clamped-clamped configuration. A normally open plunger valve was designed and characterized. The device is manufactured from silicon. Gas flow rates of up to 37 SCCM can be proportionally controlled between 10\% and 100\%. A 10\% leakage is always present at low backpressures (< 10 kPa) and increases to roughly 20\% at 75 kPa backpressure. The structure has been tested up to backpressures of 300 kPa without damage to the structures, but the leakage increases to over 95\%. Our unprecedented microvalve concept shows that it is possible to manufacture all-silicon MEMS microvalves with proportional control of the flow rate. The presented work is a proof of concept to test the capabilities of the NED technology for the use in microvalves. There are plans to decrease the leakage in future designs by introducing an additional sealing layer as well as manufacturing a shutter instead of a plunger design.}, language = {en} } @misc{RuffertMonsalveGuaracaoVoelzetal., author = {Ruffert, Christine and Monsalve Guaracao, Jorge Mario and V{\"o}lz, Uwe and Jongmanns, Marcel and Betz, Bj{\"o}rn and Langa, Sergiu and Amelung, J{\"o}rg and Wiersig, Marcus}, title = {Rapid characterisation of mixtures of hydrogen and natural gas by means of ultrasonic time-delay estimation}, series = {Journal of Sensors and Sensor Systems}, volume = {13}, journal = {Journal of Sensors and Sensor Systems}, number = {2}, issn = {2194-878X}, doi = {10.5194/jsss-13-179-2024}, pages = {185}, abstract = {The implementation of the "power-to-gas" concept, where hydrogen and natural gas are blended and transported in the existing network, requires a quick, on-site method to monitor the content of hydrogen in the mixture. We evaluate a rapid characterisation of this mixture based on the measurement of the speed of sound, using micromachined ultrasonic transducers (MUTs). Two MUT-based prototypes were implemented to analyse a mixture of natural gas and hydrogen under controlled conditions. Changes in the hydrogen content below 2 mol \% (in a mixture that was adjusted between 6 mol \% and 16 mol \%) were discriminated by both devices, including the uncertainty due to the temperature compensation and the time-delay estimation. The obtained values of the speed of sound were consistent with those calculated from independent, non-acoustic measurements performed with a gas chromatograph and a density sensor. An MUT-based flow meter is thus capable of reporting both gas intake and the molar fraction of hydrogen, provided that the source of natural gas is kept constant.}, language = {en} } @misc{UhligGaudetLangaetal., author = {Uhlig, Sebastian and Gaudet, Matthieu and Langa, Sergiu and Ruffert, Christine and Jongmanns, Marcel and Schenk, Harald}, title = {Highly integrable silicon micropumps using lateral electrostatic bending actuators}, series = {Microsystem Technologies}, volume = {30}, journal = {Microsystem Technologies}, number = {8}, publisher = {Springer Science and Business Media LLC}, issn = {0946-7076}, doi = {10.1007/s00542-024-05635-w}, pages = {949 -- 960}, abstract = {We present the design, fabrication, and characterization of an innovative silicon-based micropump with high potential for portable lab-on-chip (LoC) as well as point-of-care (PoC) applications. The actuators of the pump are electrostatic driven in-plane bending devices, which were presented earlier (Borcia et al. in Phys Rev Fluids 3(8): 084202, 2018. 10.1103/PhysRevFluids.3.084202; Uhlig et al. in Micromachines, 9(4), 2018. 10.3390/mi9040190). This paper presents the characterization results achieved with the micropump. The dielectric non-polar liquid Novec7100™ was used as a test liquid due to its adequate physical properties. When applying a periodic voltage of 130 V, a flow rate of up to 80 µL/min was detected. The counter pressure amounts up to 30 kPa and the correspondent fluidic power (volumetric flow rate times the counter pressure) was calculated to 10 µW. The pump contains passive flap valves at the inlet and outlet, which are based on a bending cantilever design. Depending on the application requirements, the micropump can be designed modularly to adjust the specific parameters by an adequate arrangement of pump base units. In this paper, the proof of principle is shown using a single base unit with different number of stacked NED-actuator beams, as well as the serial arrangement of base units. Both modular concepts target the increase of backpressure of the NED-micropump in an inherently different way compared to conventional membrane micropumps.}, language = {en} } @misc{MonsalveJongmannsKochetal., author = {Monsalve, Jorge M. and Jongmanns, Marcel and Koch, Sandro G. and Schenk, Harald}, title = {Flow measurement by means of wideband acoustic signals in single-mode waveguides}, series = {Journal of sensors and sensor systems}, volume = {14}, journal = {Journal of sensors and sensor systems}, number = {2}, publisher = {Copernicus Publications}, address = {G{\"o}ttingen, Germany}, issn = {2194-878X}, doi = {10.5194/jsss-14-275-2025}, pages = {275 -- 284}, abstract = {A novel concept of an acoustic flowmeter, based on single-mode waveguides, is proposed, implemented, and analysed in this work. Instead of transmitting a pulse diagonally across the duct's cross-section, this device operates with two ducts that operate simultaneously as pipes and as waveguides. Below the frequency threshold for single-mode propagation, acoustic waves are forced to traverse the waveguides with a plane front, precluding the possibility of beam drifting, inner reflections, and spreading losses. This enables the designer to flexibly increase the sound path and perform a highly sensitive measurement of the flow velocity and speed of sound, even if the excitation frequency is required to be kept below a relatively low value. A device based on this principle was constructed and tested for flow measurements in air. It consists of two waveguides of a circular cross-section (5 mmdiameter) coupled to electroacoustic transducers for the transmission of a wideband chirp (9.8-18.2 kHz). Usage of a wideband signal was possible due to the combined frequency response of a special kind of micromachined ultrasound transducer (MUT) and a commercial micro-electromechanical system (MEMS) microphone. The constructed flowmeter was capable of measuring flow velocities up until the transition to turbulent flow at 16 Lmin-1with a resolution of 0.3 Lmin-1, and it also detected changes of less than 0.2 ms-1in the speed of sound. This topology for flow measurement could prove advantageous for applications where gases of variable composition are conducted in ducts of diameters in the millimetre range.}, language = {en} }