Numerical investigation of the effect of spiral curvature on the flow field in a spiral channel viscous micropump

This paper investigates the effect of spiral curvature on the flow field within a newly introduced spiral channel viscous micropump. Increasing the spiral curvature increases the angle between the channel axis and the direction of upper plate motion, and more fluid is dragged normal to the axis of the channel, which changes the flow characteristics. A number of 3D models for the pump geometry with different design parameters are built and analyzed using the finite volume method. Numerical visualization of the flow field contours through the spiral channel is presented. It has been found numerically that the flow rate varies linearly with both the pressure difference and boundary velocity for a wide range of design parameters, which supports the validity of the linear lubrication model for this problem for the full range of spiral curvatures studied. Further, it is found that the error resulting from ignoring the spiral curvature exceeds 5% for spiral curvature ratio above 2. Obtained results depict a complete representation of the effect of spiral channel width, height, length and curvature on the flow field through a spiral-grooved micropump.