ESTIMATION OF WATER ENTRY FORCES, SPRAY PARAMETERS AND SECONDARY IMPACT OF FIXED WIDTH WEDGES AT EXTREME ANGLES USING FINITE ELEMENT BASED FINITE VOLUME AND VOLUME OF FLUID METHODS

Abstract

In this paper, water entry of wedges with deadrise angles ranging from 10 to 80 degrees at two different velocities is simulated. Impact forces, spray parameters, cavity formation above the chine, and secondary impact forces due to the cavity formation are investigated with particular focus on the extreme angles. To this end, a two dimensional two-phase Finite-Element based Finite-Volume (FEM-FVM) code is developed and validated against experimental data with good compliance. Free surface modeling in this software is accomplished by applying Volume of Fluid (VOF) method. In addition to the extraction of impact forces, secondary impact forces, spray characteristics, and cavity formation, it is demonstrated that there is a combined critical length and entry velocity where the spray formation stops and the spray vanishes. It is also shown that the cavity and secondary impact do not occur under these circumstances. Moreover, it is concluded that for these particular cases, there is a maximum secondary impact force that occurs for the deadrises angles less than 20o.

Keywords

• Wedge water entry
• FEM-FVM
• VOF
• Impact
• Spray
• Extreme angles