Quantification and Modeling of the Air Entrainment by a Transom Breaker
Contract/Grant Number: N00014-05-1-0121
Funding Agency: Office of Naval Research
This research is aimed at providing the basic understanding needed to develop reliable codes able to predict the behavior of the turbulent bubbly flow around surface ships. Air is entrained by surface ships and the resulting bubbly flow travels along the hull interacting with the turbulent boundary layer created around the ship. These bubbles have been shown to remain present in the wake of the ship many ship length downstream, accumulating preferentially in regions of high vorticity. To quantify the amount of air entrained at the stern of the ship the transom breaker found behind a ship is modeled, in a first approximation, as a 3-D, strong, deep-water hydraulic jump. In order to model the physical mechanisms responsible for the entrainment of air in these flows, an experimental study of a hydraulic jump generated in a laboratory flume is been performed. The flow in the region closest to the leading edge, or toe (where most of the entrainment occurs) is been studied using a combination of high-speed visualizations and feature tracking techniques similar to those used in PIV.
Videos of Research
|Velocity distribution in 2-D breaker||Two views of the 3-D breaking wave|
High-Speed detail of the plunging point in the breaking wave case
Related Papers and Presentations
F.J. Rodríguez-Rodríguez, A. Aliseda and J.C. Lasheras. "The mechanism of air entrainment in a deep water hydraulic jump." Experimental Thermal and Fluid Science. Vol. 35, Issue: 2. pp: 301-310, (2011).
A. Aliseda and J.C. Lasheras. "Preferential Concentration and Rise Velocity Reduction of Bubbles Immersed in a Homogeneous and isotropic Turbulent Flow." Physics of Fluids. Vol. 23, Issue 9. 093301 (2011).
P. Martínez-Legazpi, J. Rodríguez-Rodríguez, A. Korobkin and J.C. Lasheras. "Formation of Corner Waves in the Wake of a Partially Submerged Bluff Body" Submitted Journal of Fluid Mechanics. (2012).
P. Martínez-Legazpi, C. Marugan-Cruz, J. Rodríguez-Rodríguez and J.C. Lasheras. "Plunging to spilling transition in corner surface waves in the wake of a partially submerged vertical plate." Experiments in Fluids. 54:1437-1448 (2013).