A cylinder rotating in an off-center position across a microchannel is known to generate a net flow for highly viscous Newtonian fluids. The mechanism is also known to be a viable option for the transport of viscoelastic or viscoplastic fluids albeit with a slight drop in performance. In the present work, the applicability of this mechanism is numerically investigated for the transport of (inelastic) time-dependent fluids obeying the structural-based Quemada model. By numerically solving the equations of motion, it is predicted that viscous micropumps can be used for the transport of thixotropic fluids although the obtained numerical results suggest that there exists a critical thixotropy number (a dimensionless number related to the fluid’s natural time) at which the flow rate is at its lowest value. It is shown that the critical thixotropy number can be avoided from the response of the fluid by properly choosing the geometrical parameters of the device. The general conclusion is that viscous micropumps can be deemed as an efficient mechanism for the transport of thixotropic fluids in microfluidic systems provided that the thixotropy number is sufficiently small, i.e., the fluid is strongly thixotropic. The device is predicted to be more suitable for anti-thixotropic fluids.

众所周知，在微通道上偏心位置旋转的圆柱体可以产生高粘性牛顿流体的净流。该机构也被认为是传输粘弹性或粘塑性流体的可行选择，尽管性能略有下降。在目前的工作中，对该机制的适用性进行了数值研究，以服从基于结构的克马达模型的（非弹性）时间相关流体的传输。通过对运动方程进行数值求解，预测粘性微型泵可用于触变流体的输送，尽管获得的数值结果表明存在临界触变数（与流体自然时间相关的无量纲数），在该临界触变数处，流量处于最低值。结果表明，通过正确选择装置的几何参数，可以避免流体响应出现临界触变数。总体结论是，只要触变数足够小，即流体具有强触变性，粘性微泵可以被视为微流体系统中传输触变流体的有效机制。预计该装置更适合抗触变流体。