Development Of Synthetic Dolphin Blubber Compliat Coatings

QUEST Integrated, Inc. (formerly Flow Research) proposes to develop and fabricate compliant coatings synthesizing dolphin skin/blubber for use on underwater vehicles to achieve drag and flow noise reduction. Guided by the theory of the hydrodynamic response of viscoelastic materials, the design of the compliant coatings will be aided by using a computer code combining finite element techniques, viscoelastic material theory, and available acoustic data from studies on live dolphins. Following the current trend of compliant coating research, we will conisder three different coatings all with a thin but strong exterior layer that serves as the protective skin for the interior layers, which have the desired viscoelastic properties but are weak in mechanical strength against wear and tear. Three types of interior layer(s) will be evaluated: an isotropic layer, multiple (progressively softer) isotropic layers, and multiple fiber-reinforced layers. These compliant coatings will be fabricated, and their viscoelastic properties will be measured at the material laboratory of the Naval Surface Weapons Center. One of the coatings will be selected to be installed on a "self-propelled" slender body for laboratory testing in a towing tank as a means for assessing the practicality and robustness of the coating. A novel visualization technique will be used to determine the potential of the coating for drag reduction. For measuring the flow noise, a microphone will be intalled inside the body. ANTICIPATED BENEFITS: This development will improve the performance of underwater and surface vehicles, for military and civilian applications; lead to increases in the speed and range of the vehicles, enhancing their mobility and reducing their vulnerability and operational cost; and result in flow noise reduction, and thus decreased detectability. The coatings may also be applied to propellers/impellers to increase thrust output. Commercial applications include use as coatings on ship hulls and as liners in various pipelines.