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The paper presents results of measurements and analysis of the flow electrification process in the Swinging Cylinder System. This system is similar to the Couette system. The proposed system has the ability to perform different movement function of the internal electrode. The identification of the electrification process was made based on small step movements of the electrode in both directions. The battery powered measurement device was mounted inside the movable inner cylinder. In addition, it allows for the wireless transmission of the measured data. A series of the electrification current measurements were made in response to the impulse changes of the speed of the measuring electrode. The identification of simple process models of first and second order was made on the basis of the results. [ABSTRACT FROM PUBLISHER]

The article presents the results of measurements and analysis of the flow electrification process. The research is presented with a new type of measurement instrument, in which one of the electrodes moves in an oscillating manner. The arrangement comprises two parallel plates and the liquid is relocated in one dimension. One of the electrodes is in the form of a copper wire. As a result, the liquid distribution is assumed as very simple and similar to the classic Stokes boundary layer. The electrification current measurements for different oscillation frequencies were performed in such an arrangement. The basic characteristics of the measured current and the determined process models were tested. The nonlinear approach and the linear approach were used. In the case of the nonlinear mode, the displacement of electrode was employed as an input. Hammerstein's mode with a piecewise linear input nonlinearity estimator was used for identification. In the case of the linear mode, the calculated velocity magnitude was used as an input into the system. The discrete time Output Error model and the Transfer Function model were used as a linear model. In each case, very good compliance was obtained between the simulation responses and the actual current measurements. [ABSTRACT FROM PUBLISHER]

This paper is related to the phenomenon of streaming electrification. The selected results of nonlinear identification of the electrification process are presented. We described the signals used for identification and validation and then two structures of the models used: the nonlinear autoregressive model and the Hammerstein-Wiener model. We then conducted parametric identification and compared the obtained results. We used the Gauss function as the input signal. In the case of the autoregressive model, we used the sigmoid network to estimate the nonlinearity. In the case of the Hammerstein-Wiener model, we tested various types of input nonlinearities. The piecewise linear nonlinearity estimators turned out to be the most effective. Results for the most effective models of both structures: the results of the nonlinear ARX model and the Hammerstein-Wiener model were similar and had varying fit values in the range of 1 to 3 percent. They also had similar generalisation features. In all cases, we also obtained similar shapes of the processes of residues and correlation functions. They indicate a relatively faultless representation of the responses of models as well as certain differences, especially in the end part of the processes representing the given process. [ABSTRACT FROM PUBLISHER]

The paper presents an analytically derived model of electrification phenomena in turbulent flow. Mechanisms of diffusion, convection, and conduction were taken into account. Distributions of current density where determined for the whole range of liquid conductivity and viscosity. The equations are derived assuming an isothermal incompressible Newtonian flow in a pipe in the steady state in time and space. [ABSTRACT FROM AUTHOR]

The subject matter of this paper refers to the application of optical spectral diagnostics to the detection of electromagnetic waves generated by partial discharges. The research work refers to creeping discharges at bakelite/oil interface. The analysis of optical spectrum time changes was performed. The influence of voltage on the changes of the creeping discharge optical spectrum was determined. The spectrum distibutions were determined in the area of creeping discharges. The results obtained at this stage of the research can constitute a source material for people dealing with issues connected with electrical material science and diagnostics of insulation systems. [ABSTRACT FROM AUTHOR]

In this paper the analysis of the influence of C60 fullerenes on flow electrification of mineral insulating oil during aging is presented. Three sets of samples, one fresh and two aged for 24 h and 96 h were tested for their electrification properties using an improved version of a spinning disk system. The relations between C60 concentration and electrification current were determined for different rotational velocities. It is shown, that C60 may significantly reduce or increase the electrification current in mineral oil, depending on fullerenes concentration. The possible causes of observed behavior are analyzed. [ABSTRACT FROM AUTHOR]