Jacobs School of Engineering

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

PDFFlow structure and air entrainment mechanism in a turbulent stationary bore.

PDFQuantification and Modeling of the Air Entrainment in the Stern Flow Region. (30Mb)

PDFA. Aliseda and J.C. Lasheras. "Effect of Buoyancy on the Dynamics of a Turbulent Boundary Layer Laden with Micro-bubbles." Journal of Fluid Mechanics, Vol. 559, pp. 307-334, (2006).

PDFC. Martínez-Bazán, J. Rodríguez-Rodríguez, G. Deane, J.L. Montañés and J.C. Lasheras. "Considerations on Bubble Fragmentations Models." Journal of Fluid Mechanics. Vol. 661, pp. 159-177, (2010).

PDFF.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).

PDFA. 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).

PDFP. 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).