A Detailed Study of Transom Breaking Waves. Part 2
Abstract
Detailed measurements of the turbulent multiphase flow associated with wave breaking present a unique instrumentation challenge. Measurement systems must be capable of high sampling rates, large dynamic ranges, as well as be capable of making measurements in water, air and optically opaque regions. An experiment was performed on Carriage 2 in the Deep Water Basin at the Naval Surface Warfare Center, Carderock Division, (NSWCCD) in October and November 2008 to measure various characteristics of the breaking wave generated from a ship transom. The primary objective of this work was to obtain full-scale qualitative and quantitative flow field data of a large breaking transom wave over a range of transom drafts and Froude numbers. This test was the second part of a test performed in October 2007. Several types of measurements were made of the transom stern wave. Sinkage and trim were measured using two string potentiometers. Drag, vertical and side forces were measured using block gages. To quantify the free surface deformation, several techniques were used, including a scanning LiDAR system, laser sheet flow visualization (Quantitative visualization or QViz), Senix Ultrasonic acoustic distance sensors, and high speed video. Additional measurements were made using the Nortek Acoustic Wave and Current (AWAC) profiler, which measured velocity and acoustic backscatter in the water column, and a SonTek Acoustic Doppler Velocimeter (ADV), which measured water velocity. A Defocused Digital Particle Image Velocity (DDPIV) system, which utilizes optical measurements of the flow to measure bubble size, was used to measure the bubble size distribution at a fixed depth aft of the transom. An array of impedance void fraction probes was also used to measure the entrained air at various locations and depths behind the stern.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2010
- Accession Number
- ADA515738
Entities
People
- Anne M. Fullerton
- David Drazen
- Don Walker
- Lauren Russell
- Lisa Minnick
- Michael Capitain
- Thomas C. Fu
- Toby Ratcliffe
Organizations
- Naval Surface Warfare Center Carderock Division