Lubricant Depletion in Liquid Infused Dovetail Cavity for Viscous Laminar Flow

Liquid infused surfaces (LIS) display a wide range of properties owing to their omniphobicity. However, liquid infused surfaces are prone to drainage failure due to external shear flow. In this work, we numerically study the effect of iscosity ratio (μr) in bulk flow over a dovetail shaped cavity in laminar regime. Water (μr = 0.2) and 50% aqueous water glycerol mixture (μr = 1.8) are considered external liquids. Drainage of lubricant within the microchannel with time was observed. Meniscus formation had a direct correlation with flow rate and viscosity ratio as seen by the vortex formation. Depletion of lubricant has a linear relation with the flow rate for water. A two-regime depletion was observed for 50% aqueous water-glycerol mixture. For Reynolds number (Re) ≥ 500, LIS failed and at Re ≤ 500, a stable meniscus shape was observed. Results presented will aid in better design of liquid infused surfaces depending on flow rate and viscosity ratio for a dovetail cavity microchannel.