Session: 06-03-06 Fluid-Structure, Multi-body and Wave-body Interaction - VI

Submission Number: 176405

Experimental Modeling of Impact Pressures Due to Plate Water Entry at Varying Drop Heights and Aeration Levels 

Water entry impacts are critical for understanding extreme hydrodynamic loads on ships, coastal defenses, and offshore structures, where transient high pressures threaten structural integrity. However, the effect of water–air mixtures on impact dynamics during plate water entry remains insufficiently quantified. This study experimentally investigates the combined effects of impact velocity and aeration on flat-plate water entry using a controlled drop-test setup. Impact velocity was measured via image-based tracking and an accelerometer, showing close agreement. Pressure sensors and a fiber-optic reflectometer were used to capture temporal and spatial distributions of pressure and air fraction, with both global and local air fractions evaluated to analyze aeration effects on peak pressure. Results show that higher aeration significantly reduces peak pressures and increases rise times, confirming the cushioning effect of entrained air. A dimensionless empirical form was obtained to relate peak pressure to pressure rise time. The general extreme value distribution best describes the probability distribution of peak pressure across all test conditions. A new dimensionless relationship is proposed to predict peak pressure from impact velocity, geometric parameters, and aeration level, showing consistency across datasets and enabling extrapolation to larger scales. These findings provide systematic data and generalized scaling insights to improve the design and safety assessment of marine and coastal structures under extreme hydrodynamic loads.

Presenting Author: Sheng-Mei Lin National Sun Yat-sen University

Presenting Author Biography: Mr. Sheng-Mei Lin earned her master’s degree from the Department of Mechanical and Automation Engineering, I-Shou University, Kaohsiung, Taiwan. She is currently a PhD student in the Department of Marine Environment and Engineering at National Sun Yat-sen University, Kaohsiung, Taiwan, focusing on experimental and computational fluid dynamics as well as machine learning applications.

Authors:

Sheng-Mei Lin National Sun Yat-sen University
Wei-Liang Chuang National Sun Yat-sen University
Ting-Chieh Lin National Taiwan Ocean University