Experimental investigation on the slamming loads of a truncated 3D stern model entering into water

Abstract

Slamming load during water impact is one of the main concerns for the design of marine structures. However, accurate prediction of impact pressure largely relies on two-dimensional or simplified three-dimensional structures due to the difficulty in modeling complicated fluid forms such as flow separation and air cavity. In order to improve the prediction of slamming loads in complex three-dimensional models, a truncated stern model impacting water was investigated experimentally through a series of free drop tests. The falling kinemics (water entry depth and acceleration) and slamming loads (pressure and vertical force) were measured through arranging the sensors. Details of impact characteristic including falling kinemics and slamming pressure were presented. In order to clarify the 3D effects, the 2D CFD numerical results were compared with experimental results, showing that the numerical results are larger than the experimental ones with an average of 21%. Finally, influence of water entry velocity on the non-dimensional pressure was further discussed to improve the application. Some factors related to impact velocity such as air pocket and jet flow can influence the pressure which should be paid attention.