【摘要】 根据对称性与周期性,建立了混沌螺杆螺槽的混合过程动力学模型。采用有限体积方法,得到一个周期长度速度场数值解,将结果映射到3个周期长度的相空间内对混沌混合过程动力学进行分析与表征。结果表明,常规的层流混合和混沌混合区域共存,两种混合区域通过"8"字型同宿轨道包围的KAM岛分割开来,内部为常规混合区域,外围为混沌混合区域。示踪粒子在三维重构的相空间内动力学行为清楚地刻画了系统向混沌进发的过程及速度。另外,由于长度有限,混沌混合的作用受到限制,不再具有无穷的自相似结构,可以采用KAM岛的区域大小来表征混合。更多还原

【Abstract】 In terms of the symmetry and periodicity,the model of mixing dynamics in the Chaos Screw channel was presented.Adopting Finite Volume Method,the computational results of the velocity field obtained in one periodic length were mapped into the phase space with three periodic length to characterize the mixing dynamics.The results show that the regular laminar mixing coexists with the chaotic mixing.The zones are separated by the KAM island shell surrounded by the homoclinic manifold which wanders "8" orbit in the cross-section of the channel,the inner zones is subjected to the regular laminar mixing while the outside to the chaotic mixing.The dynamic performances of tracer particles in the reconstructed phase space clearly describe the rate and the processing at which the system approach chaos,where the perturbation of period three plays a critical role.In addition,the effect of chaotic mixing is inhibited due to the limitation of the channel length and so the infinite self-similarity structure does no longer holds true.The scale of KAM island can be adopted to characterize the mixing in such a screw channel.更多还原