Research into basic sensor technology for indirect measurement of viscosity and viscosity development of viscous materials by measuring their permittivity

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The aim of the project is the realization of a technical solution for non-invasive measurement of the viscosity of fluids and its change over a pipe’s cross section. The proposed project includes fundamental researches of the not completely known relation between the viscosity and permittivity of a fluid. Based on the new findings, a tomographic in-line sensor for the measurement of the complex permittivity over different pipe’s cross sections in the microwave frequency range and the viscosity is build and examined. Within the project, the sensor principle is investigated and employed for two different applications. This includes the extraction of the spatial resolution of the hydrogen loading of liquid organic hydrogen carrier (LOHC-) compounds. LOHC-compounds are a promising approach for the storage and the transportation of energy generated by regenerative sources. For reliable use, it is essential to measure the hydrogen loading of LOHC compounds, which correlates with the stored energy. Moreover, it is planned to investigate the viscosity development of non-newtonian, viscose fluids, e.g. polymer melts in different pipe geometries. Until now, the fundamental relation between the geometry and viscosity of viscose fluids is unknown for certain configurations, which will also be examined in the course of this project. The first project phase comprises the design of a sensor system measuring the complex permittivity as a function of the temperature, shear rate and pressure of the fluid. Due to a parallel rheological characterization of the fluids, the relation between the measured values permittivity and viscosity can be extracted. Based on the findings of the previous investigations, the second project phase contains the design of a tomographic contactless measurement system for indirectly measuring the viscosity over a permittivity measurement. Meanwhile, a suitable test stand, which pumps fluids with different viscosities through different pipe geometries, is realized. To dimension and chose the pipeline elements and to research an extraction method of the viscosity and pipe geometry depending zeta-values, parallel simulations are done. The third project phase comprises the measurements of the local resolution of the viscosity at the test stand. Besides validating the functionality of measuring the hydrogen loading of the LOHC, the measurements serve for a detailed analysis of the pressure drop depending on the pipe geometry and the viscosity.