Experimental study of liquid droplets impact on powder surface: The application of effective dimensionless parameters in analysis

Spreading dynamics of liquid droplets impacting onto powder bed are experimentally studied using high-speed photography. Dimensionless numbers— We , Re the modified * and ∗ corrected by substrate deformation—are used to analyze impact behaviors droplets. The spreading time maximum factor further analyzed. is accurately described a universal scaling law that obtained from dimensionless vs. effective Weber number ( ), found follow classic β max = f ).