3D Numerical Simulation of Micro-Jet Excitation

Excitation of round laminar air micro-jet by volumetric force and by pulse-periodic heat source was simulated using the FlowVision software package in 3D formulation at normal conditions. Heat source and volumetric force imitate an influence of electrical discharge. Air jet was formed by a circular cross-section channel with inner size of 1 mm with the Poiseuille velocity profile at inlet boundary, the maximum profile velocity was 5 m/s. The conditions corresponded to the formulation of the problem considered earlier in the experiment. Dependence of large-scale vortex formation from volumetric force frequency and amplitude was obtained. Amplitude of force corresponding to the effect of the discharge on the air jet was determined and was set to 5 μN. For round laminar jet the exited oscillations of the jet was obtained at frequency range 500–2500 Hz, further increase in the frequency of oscillations left the shape of the jet close to the initial. Lack of influence of pulse-periodic heat source on flow structure was discussed. The results obtained demonstrate that the main contribution from the corona discharge to the jet in the experiment is provided by the volumetric force (ionic wind), and not by the heating of the gas.