The influence of splitter on the flow dynamics in a continuous-discrete pulsing jet fluidic oscillator

This paper studies the internal flow dynamics of a continuous-discrete pulsing jet fluidic oscillator and the influence of splitter on its outlet peak velocity and oscillating frequency. For that purpose, two-dimensional unsteady numerical simulations were conducted, covering five different inlet mass flowrates $\dot{m}$ and three oscillator models (two continuous-discrete pulsing oscillators with different splitting distances and a continuous sweeping oscillator).Results show that there are at least three different velocity peaks in one period at both outlets of continuous-discrete pulsing oscillators. When the splitting distance increases, the first peak velocity (U_max,1,O) decreases, the third one (U_max,3,O) increases, while the second peak velocity (U_max,2,O) is less affected; the three peak velocities generally satisfy U_max,3,O＞U_max,1,O＞U_max,2,O , unless $\dot{m}$ is extremely large or small.When the splitting distance increases, oscillating frequency decreases at first and then increases, but the frequency of continuous sweeping oscillator is always the highest and the difference of the other two keeps rising as $\dot{m}$ increases.Results also show that when the splitting distance was increased or $\dot{m}$ was reduced to a certain extent, the outlet velocity’s oscillating pattern changes, including the significant velocity fluctuations both before and after U_max,1,O, the phase shift and the great amplitude increase of U_max,2,O.The research results are of great importance in supporting the design optimization of the continuous-discrete pulsing oscillator and the development of flow control method with this kind of fluidic actuators.