Waterjet Wake Characterization Suite

The US Navy is interested in analytical methods and tools to predict ship bubbly wake acoustic signatures for waterjet propelled surface ships with underwater waterjet outlet such as the Littoral Combat Ship (LCS). Wake features of propeller-driven ships are well studied, but the ability to perform predictive analysis and wakes from waterjet driven advanced hull forms do not currently exist. The methods suggested by the firm are assigned to analyze (1) cavitation inception and growth in the mixing region of the jet and the surrounding hull wake, (2) the bubble evolution in the turbulent flow to the far wake and (3) sound propagation in the bubbly far wake and reflection coefficients for the ship wakes. The suggested tools suite will be composed from elements preliminary proven on simplified problems and manifested the ability to predict scale effects. Their following validation by Phase I and Option 1 experiments on measurements of bubble distributions in the model wake will be performed in the water tunnel of the Saint Anthony Fall Laboratory at the University of Minnesota. BENEFITS: Commercialization will include a large variety of ships, from fast ferries to recreation boats.