The influence of viscoelasticity on primary atomization of syrup and syrup polymer solutions was studied experimentally with the coaxial air-blast atomizer.The breakup regimes were divided according to high-speed camera graphs and breakup instability characteristics on the surface of liquid jet were performed.The results proved that primary breakup of the experimental medium could be divided into three regimes

non-axisymmetric oscillation

membrane breakup and fiber breakup.However

the breakup transition Weber number of syrup-polymer was larger than that of syrup solution with the same viscosity.The instability wavelength on the surface of liquid was closely related to air velocity and liquid viscoelasticity

the elasticity parameter Wi was introduced in the instability wavelength theory model that considered the influence of vorticity-layer

and a new equation of instability wavelength was fitted with relevant characteristic parameters.