Jacek Nowakowski

Metrological evaluation of a 3D electrical capacitance tomography measurement system for two-phase flow fraction determination

The industrial diagnostic and monitoring systems still require new methods offering new possibilities of non-invasive observation and analysis of the two-phase gas–liquid mixture flows. This paper demonstrates a new measurement system dedicated for non-invasive void fraction calculation and flow structure identification in vertical and horizontal pipelines. The study of the metrological validation of the designed three-dimensional capacitance tomography measurement system is discussed here. This research includes the 3D ECT sensor structure optimization process, the metrological evaluation of the image reconstruction accuracy and the developed liquid void fraction calculation method efficiency, in comparison with other common techniques. As a result of the performed analysis the advantages of the designed 3D ECT measurement system for non-invasive real-time dynamic flow process identification were discussed.

Application of twin-plane ECT sensor for identification of the internal imperfections inside concrete beams

The main purpose of this paper is to investigate application of special construction of Electrical Capacitance Tomography (ECT) sensor to concrete beams internal homogeneity tests. Identification of internal imperfection inside the concrete beams is one of the main problems related to analysis of the construction structure bearing capacity. Therefore, this paper shows attempts to study the measurement prospects for this non-invasive, tomography based technique, in regard of concrete construction elements structure investigation. Presented results come from experiments with two types of internal inclusions, which cause the non-continuity at the concrete structure: soft and hard (of density lower, and higher, than this of pure concrete beam). The positions and dimensions of the imperfections were sensed with two non-invasive methods; ECT and, in order to verify the outcomes, X-ray tomography imaging. The range of application and the accuracy of both methods, in aspect of measurement of material concentration changes inside concrete beams, are discussed here. For the purpose of measurement results interpretation, in case of ECT only capacitance, unprocessed measurement data were analyzed, since such raw data processing do not introduce additional soft-field effect inverse problem solution errors.

MULTI PHASE FLOW MEASUREMENTS WITH THE APPLICATION OF ECT/ERT DECART MULTIMODALITY TOMOGRAPH

The multi-phase flow measurements are very important tasks in many areas of industrial processes applications. One of them is undersea exploration of oil in the petroleum industry. The submitted paper presents application of DECART tomograph designed and built in Lodz University of Technology together with combined measurements of signals acquired from gamma ray measurement system. Use of all measuring modalities allowed for performing measurements of a flow composed of sea water, oil and gas. The paper presents theoretical principles applied to design multimodality tomograph and results of experiments performed in the University of Bergen. Measurement confirmed that multi-modality approach allows giving fast and reliable on-line results of measurements of composition of multi-phase flow. Applied algorithms allowed to speed up on-line measurements and presenting results in a form required in industrial applications. The derived conclusions can be used as guidelines for preparation of industrial applicable construction of tomograph.

State Delays Extraction in the Fractional-Order State-Space Model

In the paper we analyse a fractional-order linear state-space model with multiple delays. We show that the multiple delay in the fractional-order state-space model introduces higher integer-order discrete differentiation action. Two fractional order state-space models without delays are derived. The equivalent models may be useful in the system stability analysis. The investigations are supported by numerical examples.