Computational Treatments of Cavitation Effects in Near‐Free‐Surface Underwater Shock Analysis

• Published in: Shock and vibration Vol. 8; no. 2; pp. 105 - 122
• Main Authors: Sprague, Michael A., Geers, Thomas L.
• Format: Journal Article
• Language: English
• Published: Hindawi Limited 01-01-2001
• ISSN: 1070-9622; 1875-9203
• DOI: 10.1155/2001/853074

Fluid cavitation constitutes an expensive computational nuisance in underwater‐shock response calculations for structures at or just below the free surface. In order to avoid the use of a large array of cavitating acoustic finite elements (CAFE), various wet‐surface approximations have been proposed. This paper examines the performance of two such approximations by comparing results produced by them for 1‐D canonical problems with corresponding results produced by more rigorous CAFE computations. It is found that the fundamental limitation of wet‐surface approximations is their inability to capture fluid‐accretion effects. As an alternative, truncated CAFE fluid meshes with plane‐wave radiation boundaries are shown to give good results. In fact, a single layer of CAFE is found to be comparable in accuracy to the better of the wet‐surface approximations. The paper concludes with an examination of variations in CAFE modeling.