Study on the breakup of liquid jet in a coaxial swirling compressible gas flow

The breakup length and position of liquid jet are the important parameters to determine the atomization quality. The nonlinear dispersion equation is used to study the breakup length and position of liquid jet with cavitation bubbles in a coaxial swirling compressible gas flow. First, the comparison of the jet breakup characteristics under linear and nonlinear stability theories is made, and then the effects of swirling gas, fluid compressibility and cavitation bubbles on jet breakup length are analyzed. The results show that the second-order perturbation may accelerate the breakup of liquid jet and may also inhibit the jet breakup when nonlinear stability theory is taken. In addition, the breakup position of liquid jet may appear after the main droplet and also appear after the satellite droplet. With the increase in gas rotational strengths, fluid compressibility and bubble volume fractions, the breakup length decreases, which indicates that swirling gas, fluid compressibility and cavitation bubbles can accelerate the jet breakup to a certain extent. In general, the effect of fluid compressibility on jet breakup length is the most obvious.