N252-098 TITLE: Flow-Exposed Conformal Array Acoustic Elements

OUSD (R&E) CRITICAL TECHNOLOGY AREA(S): Advanced Materials

The technology within this topic is restricted under the International Traffic in Arms Regulation (ITAR), 22 CFR Parts 120-130, which controls the export and import of defense-related material and services, including export of sensitive technical data, or the Export Administration Regulation (EAR), 15 CFR Parts 730-774, which controls dual use items. Offerors must disclose any proposed use of foreign nationals (FNs), their country(ies) of origin, the type of visa or work permit possessed, and the statement of work (SOW) tasks intended for accomplishment by the FN(s) in accordance with the Announcement. Offerors are advised foreign nationals proposed to perform on this topic may be restricted due to the technical data under US Export Control Laws.

OBJECTIVE: Develop a shock-hardened, modular, hydrophone for the exterior of flow-exposed hull surfaces, (e.g., the bow array) for better acoustic detection performance and decreased maintenance.

DESCRIPTION: Submarines and other undersea warfare systems (USW) use passive sensor information to develop track information (bearing, range, course, and speed vs. time) of maritime entities. Elements of the submarine bow array within the AN/BQQ-10 submarine sonar system have traditionally been embedded inside the outer hull within a thick layer of material.

While the material has historically provided performance benefits, the position of hydrophones in the traditional design has meant that individual hydrophones, if failed, would require extensive work to repair or replace. Traditional designs have considered each constituent hydrophone to be an element of the whole. This makes replacing or repairing each individual hydrophone prohibitively costly.

The Navy seeks a hydrophone and modular array design and prototype that is formed modularly with surface-mounted hydrophones. This will minimize the cost and complexity of any repairs that might be required after initial installation. The prototype will undergo Navy testing to determine that the design meets the Navy’s requirement as a pre-requisite to making a decision to adopt the new design for future Navy arrays. Currently there is no commercial product that meets this need.

Key elements of such a design would be to retain or improve on the performance associated with current hull-mounted hydrophones. An example is the DT-574 hydrophone. Individual hydrophone elements will be replaceable while maintaining hydrodynamic smoothness across the speed range expected of submarine operations. The design will have a rho of 1.03, making the total array either be neutrally buoyant or even slightly positively buoyant . The thickness of the array would need to be no more than 9.5 inches.

The hydrophone should be able to achieve non-degraded pressure-sensing capabilities while exposed to travel induced flow. In addition, the hydrophone will need to survive shock. For flank and sail locations the hydrophone would need to achieve the threshold Shock Grade B qualification. For bow implementation, the hydrophone would need to achieve Shock Grade A qualification.

The technology architecture will be extensible to multiple types of hull arrays. In addition to requiring that the flow-exposed acoustic elements meet minimum lifetimes of numerous years, the Navy would also be interested in processes to assist operators and maintainers to understand how long each element could be expected to last before replacement would be required.

Work produced in Phase II may become classified. Note: The prospective contractor(s) must be U.S. owned and operated with no foreign influence as defined by 32 U.S.C. § 2004.20 et seq., National Industrial Security Program Executive Agent and Operating Manual, unless acceptable mitigating procedures can and have been implemented and approved by the Defense Counterintelligence and Security Agency (DCSA) formerly Defense Security Service (DSS). The selected contractor must be able to acquire and maintain a secret level facility and Personnel Security Clearances. This will allow contractor personnel to perform on advanced phases of this project as set forth by DCSA and NAVSEA in order to gain access to classified information pertaining to the national defense of the United States and its allies; this will be an inherent requirement. The selected company will be required to safeguard classified material during the advanced phases of this contract IAW the National Industrial Security Program Operating Manual (NISPOM), which can be found at Title 32, Part 2004.20 of the Code of Federal Regulations.

PHASE I: Develop a concept for a modular hull array architecture and a replaceable surface-exposed hydrophone that meet the Description parameters. Show feasibility through analysis, modelling, simulation, and testing. The Phase I Option, if exercised, will include the initial design specifications and capabilities description to build a prototype solution in Phase II.

PHASE II: Develop, demonstrate, and deliver a representative prototype of the solution for both modular array architecture and individual hydrophone performance. Demonstrate the prototype meets the required range of desired performance attributes given in the Description. System performance will be demonstrated through installation and prototype testing conducted by the Navy.

It is probable that the work under this effort will be classified under Phase II (see Description section for details).

PHASE III DUAL USE APPLICATIONS: Support the Navy in transitioning the technology to Navy use for hull-mounted arrays for future spirals of a submarine class (e.g., Virginia-class submarines) or a future submarine class (e.g., future SSN). Support the Navy in transitioning the technology to Navy use aboard submarines. Demonstrate and report on performance during laboratory testing. The prototype will be integrated into submarine arrays for which IWS 5.0 develops updates.

The technology could be extended to any passive sensor, including sensors aboard surface ships and unmanned vehicles. The technology would be of greatest use in large or complex arrays where individual hydrophone failures carry disproportionate risk of distorting total array performance, such as arrays for ocean exploration in support of the oil and gas industry.

REFERENCES:

1. Butler, John H. and Sherman, Charles H. "Transducers and Arrays for Underwater Sound, Second Edition, 2016." Springer, Switzerland, 2016. https://search.worldcat.org/title/958255932
2. "AN/BQQ-10 Acoustic Rapid Commercial Off-the-Shelf Insertion (A-RCI) Sonar." Director Operational Test and Evaluation. https://www.dote.osd.mil/Portals/97/pub/reports/FY2018/navy/2018arci.pdf
3. "Military – Sonars on Submarines." Massa Products Corp. https://www.envlab.eu/documents/Papers/Massa%20-%20Military%20-%20Sonars%20for%20Submarines.pdf
4. "National Industrial Security Program Executive Agent and Operating Manual (NISP), 32 U.S.C. § 2004.20 et seq. (1993)." https://www.ecfr.gov/current/title-32/subtitle-B/chapter-XX/part-2004

KEYWORDS: Hydrophone-based passive array; modular array; undersea warfare systems; DT-574 hull array transducers; neutrally buoyant; surface-mounted hydrophones

TPOC 1: Steven Francis
(401) 832-5217
[email protected]

TPOC 2: Katharine Tarasuk
(401) 832-8442
[email protected]

---