US Navy Completes Testing Cobra Bow Bulb

Naval Surface Warfare Center (NSWC) Carderock Division researchers complete testing of bulb bows for DDG 51-class.

Partnering with Program Executive Office (PEO) Ships and the Naval Sea Systems Command (NAVSEA) Fleet Readiness Research and Development Program, NSWCCD conducted testing as part of the Navy's overall initiatives to reduce fuel consumption.

Located near the waterline, the bow bulb is an inverted tear drop shape that protrudes from the hull and is designed to reduce the ship's wave resistance. Specifically, the bow bulb creates a wave designed to interfere with the existing bow wave which reduces the amount of drag on the ship as well as fuel consumption and engine exhaust emissions.


"It is my hope that the DDG 51 class bow bulb will parallel the success of previous [NAVSEA] sponsored designs such as the stern flap, and not just improve the capabilities of the Navy's combatants, but provide for a reduction in fuel consumption and for millions of dollars in cost savings as well," said Dominic Cusanelli, NSWC Carderock Bow Bulb testing project lead, who developed the current bow bulb design for use on a naval combatant in the early 1990s. 


Through computational fluid dynamics, NSWC Carderock designed and evaluated more than 20 bow bulb prototypes for DDG 51-class ships. Following the evaluation, NAVSEA selected the four most promising bow bulb prototypes for fabrication and model testing. The model tests will identify the bulb design with the best potential for powering and fuel reduction.