The Role of Drop Shape in Impact Force

TL;DR

This paper investigates how the shape of falling drops influences impact force, revealing that shape can cause over tenfold differences and introducing a universal model for prediction applicable across various shapes.

Contribution

It uncovers the critical role of drop shape in impact force and develops a universal cylinder model based on self-similarity principles for accurate impact force prediction.

Findings

Impact force varies by over an order of magnitude due to shape.

Self-similarity in impact dynamics across different shapes.

Universal model accurately predicts impact force magnitude and timing.

Abstract

Drop impacts are ubiquitous in natural and industrial processes, yet the influence of drop shape on impact force remains a fundamental open question. Combining experiments with theoretical analysis, we show that drop shape plays a critical role, with impact force varying by more than an order of magnitude solely due to changes in shape. By uncovering self-similarity in time and cross-shape similarity across diverse drop profiles, we develop a universal cylinder model that accurately predicts both the magnitude and timing of the impact force. This study establishes a comprehensive framework for understanding impact forces across a wide range of drop shapes. Given the prevalence of drop impacts with varying shapes in real-world scenarios, our findings hold fundamental significance and have broad potential applications across industries such as soil erosion prevention, jet cutting, spray coating, and design of windshields and wind turbines.