When compound jets are covered with surfactant on both interfaces, the property of those interfaces will be viscoelastic, unlike the Newtonian fluid interface. In this paper, the effects of surface viscoelasticity are principally studied through linear stability analysis and calculated using the Chebyshev spectral collocation method. Both surface elasticity and viscosity have properties to make the jet more stable, but the physical effects behind the two influencing mechanisms are different. When the inner and outer interfaces are separately covered with surfactant, the variations of surface viscoelastic parameters affect the growth rate and dominant wavenumber differently. In addition, the sensitivity of the maximum growth rate to the surface viscoelastic parameters depends on which interface the surfactant covers. A significant increase in the surface shear viscosity reduces the influence of surface elasticity on the maximum growth rate. The long-wave assumption was adopted to derive a one-dimensional dispersion equation in an algebraic form. The comparison between the simplified expression and the numerical results validated the applicability of the one-dimensional model in the vicinity of small wavenumber.

当复合射流在两个界面上都覆盖有表面活性剂时，这些界面的属性将是粘弹性的，这与牛顿流体界面不同。在本文中，表面粘弹性的影响主要通过线性稳定性分析进行研究，并使用切比雪夫谱搭配方法进行计算。表面弹性和粘度都具有使射流更稳定的特性，但两种影响机制背后的物理效应不同。当内外界面分别被表面活性剂覆盖时，表面粘弹性参数的变化对生长速率和主波数的影响不同。此外，最大生长速率对表面粘弹性参数的敏感性取决于表面活性剂覆盖的界面。表面剪切粘度的显着增加降低了表面弹性对最大生长速率的影响。采用长波假设推导出代数形式的一维色散方程。简化表达式与数值结果的对比验证了一维模型在小波数附近的适用性。