Flow analysis inside multihelical microchannel*

Flows through helical channels are important for host of scientific and engineering applications. The curvature and torsion of the helices have been revealed to stimulate secondary flow in addition to the primary axial flow, which enhances passive in-plane mixing between fluid streams. Most of these studies involve a single spiral with circular cross-section, which in essence is symmetric. The coupled effect of asymmetry of cross-section, curvature and torsion of channel would affect the flow profile inside such tubes which are yet to be explored and understood. In this perspective, here we have presented the analysis of fluid flow at low Reynolds number inside a novel triple helical channel which consists of three helical flow paths conjoined along their contour length leading to single multihelical flow geometry. We have performed both micro particle image velocimetry (µ- PIV) and 3D simulation in FLUENT of flow of a Newtonian fluid through such flow system, the results from simulation corroborates reasonably well with experimentally determined flow profiles. Our analysis also shows that in case of triple helical channels, number of vortices increases with the helix angle.