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

该项目的目的是实现一种无创测量流体粘度及其在管道横截面上变化的技术解决方案。拟议的项目包括对流体粘度和介电常数之间尚未完全了解的关系的基础研究。在此基础上，建立了一种用于测量微波频率范围内不同管道截面复介电常数和粘度的层析在线传感器，并对其进行了测试。在该项目中，传感器原理被研究并用于两种不同的应用。这包括提取液态有机氢载体（LOHC-）化合物的载氢空间分辨率。lohc化合物是一种很有前途的储存和运输可再生能源产生的能量的方法。为了可靠地使用，必须测量LOHC化合物的氢负荷，这与储存的能量相关。此外，计划研究非牛顿流体，粘胶流体的粘度发展，例如聚合物熔体在不同的管道几何形状。到目前为止，对于某些结构，粘胶流体的几何形状和粘度之间的基本关系是未知的，这也将在本项目的过程中进行研究。项目的第一个阶段包括设计一个传感器系统，测量复杂介电常数作为流体温度、剪切速率和压力的函数。由于流体的平行流变特性，可以提取测量值介电常数和粘度之间的关系。基于之前的研究结果，第二个项目阶段包括设计一个层析非接触式测量系统，用于间接测量介电常数测量的粘度。同时，实现了一个适合的试验台，通过不同的管道几何形状泵送不同粘度的流体。为了确定管道单元的尺寸和选择，研究了一种根据ζ值提取管道粘度和管道几何形状的方法，进行了并行仿真。项目的第三阶段包括在试验台测量粘度的局部分辨率。除了验证LOHC的氢载荷测量功能外，测量结果还可以根据管道几何形状和粘度详细分析压降。

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.