A study of the electrostatic charge of the coarse water droplets

The aim of this paper is introduce the results of a measurement of the electrostatic charge of water droplets during wet steam expansion. The analysis of the charge origin was done. The achieved result shows that there is not a significant charging mechanism for the fine droplets. The dependence between the specific electrical current and the amount of liquid phase collected by the probe was found. Some models were studied to determine the origin of the electrical current. Finally a model was proposed, where the el. current is generated by the disruption of thin liquid film on the surface of the probe. The charging model was later applied for the measurement of the liquid film disruption in the new wind tunnel designed for the simulation of the flow field in the steam turbines. The measurement was performed with the air as a flowing medium and two modal droplets size distribution was found.