非牛顿流体雾化力学机理研究

本文用稳定性分析和数值计算方法研究了粘弹性液体射流雾化的力学机理。结果表明,雾化液体的 Ohnesorge 数和 Deborah 数的增大均使波频 ω_i 降低,但前者使空间增长率 k_1上升,而后者的作用相反。本文发现,对于雾化液体应使其表面扰动波的波数大于某一确定波数,并尽量降低液体的 Deborah 数。

MECHANISM ANALYSIS ON ATOMIZATION OF A NON-NEWTONIAN FLUID JET

A linearized stability analysis and a numerical calculation are carried out for the mechanism of atomization of a second-order fluid jet. In spite of the importance of atomization in applications, the mechanism that controls atomization processes has not yet been made clear even though several theorys have been proposed. In this paper the viscosity effects and elasticity effects of a second-order fluid for the atomization process are determined qualitatively and compared with Rei'z and Bracco's experimental data. Results show that the measured effects of viscosity and elasticity on the instability of a liquid jet are in good agreement with theoretical predictions.Moreover, to solve the non-linear characteristic equations system generated by the liearized stability analysis, a numerical successive iterative method is designed on the basis of random test sample and Newton iterative method. It has been shown that this iterative method is successful.