近日，中国科学技术大学穆恺团队报道了粘弹性旋流液体射流中扰动与非松弛弹性张力的解耦分析。相关论文于2026年1月27日发表在《理论与应用力学快报》杂志上。

研究组通过线性稳定性分析与能量预算分析，研究了粘弹性旋转液体射流的不稳定性，重点关注非松弛轴向/方位角弹性张力及扰动发展引起的弹性张力之间的解耦效应。首先，通过改变聚合物弛豫时间（同时保持轴向与方位角非松弛弹性张力为零），研究了扰动弹性张力的影响。研究发现，扰动弹性张力对旋转液体射流具有稳定化作用，且其影响随聚合物弛豫时间的增加而减弱。扰动弹性张力、离心力、表面张力与黏性耗散的共同作用可促进射流不稳定性，并促使主导模态向更大方位角波数转变。

随后，分别考察了非松弛方位角弹性张力与轴向弹性张力的影响。非松弛方位角弹性张力对小方位角波数模态（即m=0–1）影响甚微，但能显著抑制大方位角波数模态（即m=2–5）的不稳定性。此外，增加非松弛方位角弹性张力会促使主导模态向更小的方位角波数转变。与之相反，非松弛轴向弹性张力能极大抑制小方位角波数模态（m=0–1）的不稳定性，而对大方位角波数模态（m=2–5）的影响可忽略不计。

附：英文原文

Title: Decoupling analysis of perturbed and unrelaxed elastic tension in viscoelastic swirling liquid jets

Author: Yiqian Xu, Kai Mu, Ting Si

Issue&Volume: 2026-01-27

Abstract: Linear instability analysis and energy budget analysis are carried out to investigate the instability of viscoelastic swirling liquid jets, with a main focus on the decoupling effects of unrelaxed axial/azimuthal elastic tensions and the elastic tension caused by perturbation development. First, the effect of perturbed elastic tension is studied by varying the polymer relaxation time while keeping the axial and azimuthal unrelaxed elastic tensions absent. It is found that the perturbed elastic tension stabilizes the swirling liquid jet, with its influence being weakened as the polymer relaxation time increases. The combined effects of perturbed elastic tension, centrifugal force, surface tension and viscous dissipation could promote jet instability and facilitate the predominant mode transition to larger azimuthal wavenumbers. Then, the effects of unrelaxed azimuthal and axial elastic tension are examined separately. The unrelaxed azimuthal elastic tension has little effect on the modes with small azimuthal wavenumbers (i.e., m=0–1) but could significantly suppress the instabilities of the modes with large azimuthal wavenumbers (i.e., m=2–5). In addition, the increase in unrelaxed azimuthal elastic tension could promote the predominant mode transition to smaller azimuthal wavenumbers. In contrast, the unrelaxed axial elastic tension could greatly suppress the instabilities of the modes with small azimuthal wavenumbers (m=0–1) but only has a negligible effect on the modes with large azimuthal wavenumbers (m=2–5).

DOI: 10.1016/j.taml.2026.100659

Source: http://taml.cstam.org.cn/article/doi/10.1016/j.taml.2026.100659pageType=en