Hydromechanics Thrust

Overview

Hydromechanics for submarines and surface ships includes a broad range of technical topics in maneuvering, hydroacoustic stealth, seakeeping, and propulsion. Advances in hydromechanics yield payoffs in both war fighting capabilities and cost reduction. Improved capabilities range from quieter operation to improved maneuverability, while cost reduction occurs mostly in acquisition, specifically design-cycle reduction and its corollary, risk reduction. Two major themes underlie the hydromechanics thrust: (1) vast improvements in computational prediction capability, and (2) new concepts to be exploited in a variety of systems. Computational prediction permits exploration of a wider range of concepts (or variations of concepts), thus advancing configurations closer to their optimum and yielding performance improvement; or it allows a reduction in the number of systems that have to be built and tested, yielding cost reduction. New concepts are generally aimed at improvements in performance, though possible reductions in cost due to improved durability or simplicity of construction are always pursued.

In the Hydromechanics thrust, numerical methods are developed, validated, and applied to both submarines and surface ships.

Submarines:

• Maneuvering
• Hydroacoustic Signature Reduction
• Advanced Propulsion

Surface Ships:

• Seaway Maneuvering and Seakeeping
• Integrated Hull/Propulsor Concepts

Sub-Thrust Descriptions

• Submarine Maneuvering —
  This sub-thrust addresses the need that submarines gain the agility necessary for effective and safe littoral operations without degrading their traditionally good open-water performance. The goals of this sub-thrust are:
  • fast and accurate prediction of maneuvering;
  • application of advanced control options and robust, adaptive controller technologies;
  • demonstration of concepts that will improve performance in desired areas.

• Submarine Hydroacoustic Signature Reduction —
  This sub-thrust addresses flow-induced noise associated with the propulsor, hull, appendages and control surfaces. The goal is fast and accurate prediction of propulsor and external flow noise and its reduction to desired levels. New computational methods will provide faster, more accurate predictions to reduce system development costs, while system modifications will reduce the noise levels.

• Advanced Submarine Propulsion —
  The objectives of this sub-thrust are:
  • development and demonstration of new propulsor/stern concepts that will improve performance (powering, hydroacoustics, and cavitation);
  • development of computational tools necessary for designing and analyzing propulsor concepts of interest to the Navy.
  The goal is to meet the documented future acoustic-signature objectives and cavitation goals by providing an S&T knowledgebase and proven (demonstrated) concepts.

• Surface Ship Seaway Maneuvering and Seakeeping —
  The goals of this sub-thrust are:
  • to provide new design methods for reducing motions and hydrodynamic loads of advanced hulls in a seaway for which there is limited knowledge;
  • to develop methods for improving performance in waves and around obstacles.
  Utilization of new computational methods will reduce the cost and risk associated with acquiring new configurations.

• Surface Ship Integrated Hull/Propulsor Concepts —
  The goal of this sub-thrust is to provide new design methods for propulsor/hull interactions to achieve desired noise goals while maintaining or improving other propulsor and hull performance measures. The methods must be applicable to advanced propulsors and hulls for which there is limited knowledgebase.

Also See:

• Basic Research Description For:
  • Computational Mechanics

Point of Contact:

Program Officer
Phone: 703-696-4308
E-mail: 334HM@onr.navy.mil