抄録
Side jets, which are radial ejections, are formed at a near field in the low-density jet, such as a helium gas jet. Mixing of fluids between the jet and the ambient is enhanced at vicinity of the nozzle exit by the side jets. When the side jets are generated in a helium gas jet, the jet has periodically large velocity fluctuation in the potential core. The side jets were produced in uniform density jets by inputting periodic pulsation with a loudspeaker. The side jets in the pulsed air jets were visualized by using planar laser Mie scattering(PLMS), and the condition for generation of side jets was shown by the turbulent intensity, Reynolds number and non-dimensional frequency. Power spectra of velocity fluctuation in the pulsed air jet are similar to those in the helium gas jet if the side jets are generated.
