刚杆状聚合物和混合层中拟序结构的相互影响

用港方法（即Galerkin方法）求解多球刚杆模型位型空间分布函数的扩散方程，用拟谱方法求解物理空间的N－S方程，同时得到了加入刚杆状聚合物分子的二维混合层中拟序结构的演变过程和聚合物分子的最可几取向．计算结果较为合理地描述了聚合物分子和拟序结构的相互影响．||关键词##4多球刚杆分子模型;;混合层;;拟序结构;;谱方法

INTERACTIONS OF THE RIGID-RODLIKE POLYMER AND THE COHERENT STRUCTURES IN A MIXING LAYER

The spectral method, ie. Galerkin method and the pseudo-spectral method wereused to solve the diffusion equation of the distribution function in configurational space for amultibead-rod model and N-S equation respectively. The properties of the coherent structure ina plane mixing layer with rigid-rodlike polymer additives and the most probable orientations ofthe multibead rods were obtained simultaneously. The results indicate that adding polymer tothe Newtonian fluid will make flows have stronger vorticity diffusion, accompanied with wetherfundamental and subharmonical perturbations, less intense vortex roll-up of mixing layer, loweroscillation frequency of fundamental energy, slower rotational motion of neighboring vortices andshorter life times of eddies. As a whole, polymer additives inhibit the formation and developmentof the coherent structures. However, if Re is based on total viscosity, the conclusion abot effect ofthe viscoelasticity is reverse and thereby is in agreement with that of Azaiez ajnd Homsy2] from thespring-bead model. It is also found that the maximum absolute value of vorticity grows with theincrease of De when other parameters keep unchanged, indicating that the elasticity of polymerplays opposite roles to the viscosity on the flows. The stretching of large eddies has a great effecton the behavior of rod-like molecules since the most probable orientations of rods seems to coincidewith the local fluid stretching directions, especially in outer region of the mixing layer.l) The project supported by the National Natural Science FOundation of China (19572058).