Maxwell流体在有限长管道中作不稳定的蠕动传输:食道吞咽进程分析

解析地研究了有限长管道中Maxwell流体的不稳定蠕动传输.管壁受到不超过静止边界的收缩波作用.对无量纲形式的方程,应用长波长近似进行分析.导出了轴向速度和径向速度的表达式,评估了沿波长和管道长度方向的压力.讨论了回流现象,确定了回流极限区域.对食道中咀嚼食物(如面包、蛋白等)传输的数学公式给出了物理上的解释.可以看出,与Newton流体相比,Maxwell流体有利于在食道中的流动.与Takahashi等Rheology,1999,27:169-172]的实验结果相符合.进一步揭示了松弛时间既不影响剪应力,也不影响回流极限.发现了压力的峰值,对整数值波列是相同的,而对非整数值波列是不同的.

Unsteady Peristaltic Transport of Maxwell Fluid Through a Finite Length Tube: Application to Oesophageal Swallowing

Unsteady peristaltic transport of Maxwell fluid in a finite tube was investigated.The walls of the tube were subjected to contraction waves that do not cross the stationary boundaries.The analysis was carried out by using long wavelength approximation in non-dimensional form.The expressions for axial and radial velocities were derived and pressures across a wavelength and also across the tube-length were also estimated.The reflux phenomenon was discussed that culminates into determination of the reflux limit.Mathematical formulations were physically interpreted for the flow of masticated food materials such as bread,white eggs etc.in the oesophagus.It is revealed that Maxwell fluids are favorable to flow in the oesophagus in comparison with Newtonian fluids.This endorses the experimental finding of Tomoko Takahashi et al.Rheology,1999,27: 169-172].It is further revealed that relaxation time affects neither shear stress nor reflux limit.It is found that the peaks of pressure are identical in the integral case while the peaks are different in the non-integral case.