SBIR-STTR Award

Basic mathematical models for plate and shell vibrations with fluid loading have been well established. Complications arise, however, when practical considerations such as acoustic coatings and structural stiffeners are considered. Understanding of the physics of acoustic scattering and radiation from coated, rib-stiffened, and fluid-loaded structures is important as it provides the knowledge of the self-noise modeling of hull arrays and of the acoustic target strength of submersibles. Existing structural and acoustic simulation methods are oftentimes restricted to the flexural wave component of the radiating field, not taking into account all of the physical dynamic wave propagation mechanisms, as well as to low frequencies, not being able to consider a mid-high frequency range rich in physical phenomena. Development of a new deterministic analytical model, which incorporates higher order elastic terms, allows modeling of undersea vehicles and embedded sonar systems at high frequencies, while at the same time fully accounting for the dynamic wave propagation mechanisms and interactions with the structure. This effort will provide a universal, innovative, and computationally efficient tool for three-dimensional analytical modeling of a fluid-loaded acoustic coating affixed to a rib-stiffened backing plate, capable of representing high frequency acoustic environments not suitable for conventional finite element approaches.

Benefit:
This analytical elastic analysis tool will impact the Navy, the ship yards, and the intelligence community with a fully elastic, advanced, universal product for better understanding and design of undersea vehicle systems in the high frequency regime. Furthermore, by conducting a structured performance study of the proposed approach and devoting attention to numerical, algorithmic, and memory issues, we will produce a quantitative assessment of the necessary computational environment of the scalable software implementation in order to deliver a responsive, efficient, accelerated execution environment that can be readily interfaced with the existing Navy systems. This type of fully elastic high-frequency computing is likely to become a disruptive technology for standardized modeling and design of submarine coatings, UUV coatings, flank array sonar systems and torpedo sonar windows, providing rapid advancements in performance and usability. This structural-acoustic implementation is suitable to numerous commercial applications. Some of them include design of submersibles such as UUVs, AUVs, and Autonomous Inspection Vehicles (AIVs) used in oil and gas exploration, inshore and offshore surveys, search and salvage operations, environmental protection and monitoring, and scientific research. In addition to commercial applications, defense underwater vehicle design applications are numerous and are related to submersibles used in port and harbor security, mine countermeasures, anti-submarine warfare, and in intelligence, surveillance and reconnaissance.

Keywords:
periodic structures, periodic structures, Software Acceleration, AUVs, hull array, fully elastic models, Sonar