纤维悬浮槽流空间模式稳定性分析

Stability Analysis in Spatial Mode for Channel Flow of Fiber Suspensions

采用扰动的空间发展模式而非通常的时间发展模式,对含有悬浮纤维的槽流进行了线性稳定性分析· 建立了适用于纤维悬浮流的稳定性方程并针对较大范围的流动Re数及扰动波角频率进行了数值求解· 计算结果表明,纤维轴向抗拉伸力与流体惯性力之比H可以反映纤维对流动稳定性的影响· H增大使临界Re数升高,对应的扰动波数减小,扰动空间衰减率增加,扰动速度幅值的峰值降低,不稳定扰动区域缩小。

Different from previous temporal evolution assumption,the spatially growing mode was employed to analyze the linear stability for the channel flow of fiber suspensions.The stability equation applicable to fiber suspensions was established and solutions for a wide range of Reynolds number and angular frequency were given numerically.The results show that,the flow instability is governed by a parameter H which represents a ratio between the axial stretching resistance of fiber and the inertial force of the fluid.An increase of H leads to a raise of the critical Reynolds number,a decrease of corresponding wave number,a slowdown of the decreasing of phase velocity,a growth of the spatial attenuation rate and a diminishment of the peak value of disturbance velocity.Although the unstable region is reduced on the whole,long wave disturbances are susceptible to fibers.