Pressure estimation of wave-in-deck loading using velocity fields obtained by particle image velocimetry

Abstract

This study presents the application of a particle image velocimetry based pressure estimation method to reconstruct pressure distributions along a deck due to wave-in-deck loading. A series of experiments on wave-in-deck loading caused by focused waves were conducted in a two-dimensional wave tank to measure vertical force, pressure distributions and the PIV velocity fields under the deck. Fluid pressure fields were reconstructed by spatial integration of pressure gradients computed from Euler equation. The estimated pressures from PIV velocity data were compared and validated with the measured pressures by five pressure sensors under the deck. In the material acceleration calculation based on the Eulerian and pseudo-Lagrangian approaches, a proper time interval could be chosen to reduce errors in the pressure estimation results. The Eulerian approach provided less errors for pressure time series estimation, but the pseudo-Lagrangian approach showed a better agreement at maximum pressure. The estimated pressure fields and pressure distributions under the deck were studied to understand the mechanism of loading phenomena. Finally, the effect of the vortex beneath the leading edge during the water exit phase was discussed in relation to force and pressure measurements.