A hydrodynamic interaction between gas bubbles departed in liquid and gas supply system

In the present paper the hydrodynamic interactions between bubble - bubble and bubble-gas supply system to the needle were experimentally and numerically investigated. In an experiment in one of the needles, the air volume flow rate was constant and in the neighbouring needle, it was changed. Despite setting the constant air flow rate supply to the needle, the frequency of bubble departures fluctuated, with a change in the flow rate in the neighbouring needle. In order to identify the occurrence of hydrodynamic interaction the methods of nonlinear data analysis - wavelet analysis and FFT were used. It can be concluded that the synchronised or alternative bubble departures from twin neighbouring needles, (occurring due to hydrodynamic interaction) are possible by modifying the bubble waiting time. Moreover modification of hydrodynamic interaction between bubble – bubble actually bubble – gas supply system can be used to control the bubble departure process.