20.500.12556/RUL-186914 On the (in)equality of droplet rebound dynamics at fixed Weber number The similarity of droplet impacts on nature-mimicking superhydrophobic surfaces is traditionally compared using the dimensionless Weber number. Yet, maintaining a constant We by decoupling droplet diameter and impact velocity influences secondary forces, challenging this assumption of similarity. In this work, we investigate water droplet impacts on a lotus-leaf-mimicking laser-textured superhydrophobic aluminum surface at two constant Weber number levels (25 and 50), varying droplet diameter from 2.1 to 4.15 mm. Our results confirm that maximum spreading depends on the Reynolds number at a fixed We, as smaller, faster droplets spread less due to increased relative viscous dissipation. We propose a modified empirical scaling model that describes our data with high accuracy and generalizes successfully to external datasets. Crucially, we demonstrate that the contact time of a droplet of a given size is not strictly velocity-independent, unveiling a Weber number-dependent inertia-capillary scaling. We show that this is driven by a shift in rebound dynamics, where the relative timescale of spreading increases over retraction for larger droplets. These findings demonstrate that We is insufficient to characterize droplet rebound across varying scales and that accounting for size-dependent deviations is critical for the precise design of technologies that leverage droplet-surface interactions. droplet rebound superhydrophobic surface Weber number rebound dynamics maximum spreading coefficient contact time odboj kapljice superhidrofobne površine Webrovo število dinamika odboja maksimalni koeficient širjenja kontaktni čas true false true Angleški jezik Slovenski jezik Članek v reviji 2026-09-07 09:51:02 2026-09-07 09:51:09 2026-09-08 04:19:33 0000-00-00 00:00:00 2026 0 0 15 str. iss. 9, art. 640 Vol. 11 2026 0000-00-00 Zaloznikova Objavljeno apc 0000-00-00 0000-00-00 0000-00-00 532.21:544.722.132 2313-7673 10.3390/biomimetics11090640 290161411 Berce_..._On_the_inequality....pdf Berce_..._On_the_inequality....pdf 1 165E19E3EB89A280022A1FF781A37995 b859eff7286894da835cc4a346e31eda7c6c369dff78760fca277bab9d275b9e 35608048-aa91-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=246301 https://www.mdpi.com/2313-7673/11/9/640 1 e0f1091d-aa90-11f1-8bc5-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=246300 Fakulteta za strojništvo 0 0 0