Schnelle Lufttemperaturfühler zur Anwendung in der Präzisionsmesstechnik und Maschinenkalibrierung. - In: Technisches Messen, ISSN 2196-7113, Bd. 85 (2018), 1, S. 70-75
https://doi.org/10.1515/teme-2017-0103
Low-field NMR relaxation times distributions and their magnetic field dependence as a possible biomarker in cartilage. - In: EMBEC & NBC 2017, (2018), S. 952-955
https://doi.org/10.1007/978-981-10-5122-7_238
Automatisierte Detektion von verschmolzenen Wolframkarbiden für die Charakterisierung des Schweißprozesses :
Automatic detection of fused tungsten carbides for the characterization of welding process. - In: Technisches Messen, ISSN 2196-7113, Bd. 85 (2018), 3, S. 159-166
https://doi.org/10.1515/teme-2017-0052
Neuartiges monolithisches Tiltmeter mit Nanorad Auflösung :
Novel monolithic pendulum tiltmeter with nanorad resolution. - In: Technisches Messen, ISSN 2196-7113, Bd. 85 (2018), 4, S. 244-251
Tiltmeters with nanorad resolution in a large measurement range of ±9 mrad (±0.5˚) and a very good linearity have been developed at the Technische Universität Ilmenau in the recent years. The working principle bases on the measurement of tilt-dependent lateral forces, which act on a hanging force-compensated weigh cell (precision balance). The disadvantage is the relatively complex design of the weigh cell mechanics, the large dead weight and the high manufacturing costs. - For that reason a simplified tiltmeter was developed. It only consists of two components: a monolithic pendulum mechanics and an optical position sensor. State of the art pendulum tiltmeters contain several components that are linked by screwed, clamped or glued connections. This can limit the long-term-, temperature- or humidity stability of the tiltmeter. - The position sensor achieves a standard deviation of ˜50 pm at a measuring frequency of 10 Hz. The length of the pendulum amounts to 0.1 m, its mass is ˜62 g. With this combination, the theoretical standard deviation of the tilt measurement should result to ˜0.6 nrad at 10 Hz measuring frequency and was approved by measurements. The measurement range of the new monolithic tiltmeter amounts ˜±2 mrad.
https://doi.org/10.1515/teme-2017-0097
Convective heat transfer in engine coolers influenced by electromagnetic fields. - In: Heat and mass transfer, ISSN 1432-1181, Bd. 54 (2018), 8, S. 2599-2605
In engine coolers of off-highway vehicles, convec- tive heat transfer at the coolant side limits both efficiency and performance density of the apparatus. Here, due to restrictions in construction and design, backwater areas and stagnation regions cannot be avoided. Those unwanted changes in flow characteristics are mainly triggered by flow deflections and sudden cross-sectional expansions. In application, mixtures of water and glysantine are used as appropriate coolants. Such coolants typically show an electrical conductivity of a few S/m. Coolant flow and convective heat transfer can then be controlled using Lorentz forces. These body forces are generated within the conducting fluid by the interactions of an electrical current density and a localized magnetic field, both of which are externally superimposed. In future applica- tion, this could be achieved by inserting electrodes in the cooler wall and a corresponding arrangement of permanent magnets. In this paper we perform numerical simulations of such magnetohydrodynamic flow in three model geometries that frequently appear in engine cooling applications: Carnot- Borda diffusor, 90˚ bend, and 180˚ bend. The simulations are carried out using the software package ANSYS Fluent. The present study demonstrates that, depending on the electromag- netic interaction parameter and the specific geometric arrange- ment of electrodes and magnetic field, Lorentz forces are suit- able to break up eddy waters and separation zones and thus significantly increase convective heat transfer in these areas. Furthermore, the results show that hydraulic pressure losses can be reduced due to the pumping action of the Lorentz forces.
https://doi.org/10.1007/s00231-017-2130-4