Effects of impurity particles on flow slip on grooved surfaces

Superhydrophobic grooves offer substantial slip and drag reduction; however, real fluids are seldom completely clean. Using many-body dissipative particle dynamics simulations, we demonstrate that the presence of contaminant particles at the interface significantly decreases both local and effective slip. The primary factors influencing this effect are particle wettability and interfacial coverage, while particle size and mass have a minor role. The reduction in effective slip follows Philip's model, providing a rule-of-thumb predictor and informing designs that can tolerate or manage contamination.