Investigation of shock wave propagation and water cavitation in a water-filled double plate subjected to underwater blast.

• A eulerian compressible fluid model combines the isentropic single fluid model to solve shock wave propagation and water cavitation of water-filled double plate model. • A freestanding or softly supported outer plate has a minimal effect on the impulse transmitted to the inner plate and its motion. • Stiff support spring of the outer plate can reduce the shock wave transmitted to the gap water and also the motion of the inner plate. • Cavitation initiates in gap water near the inner plate and spreads towards the external water. • Stiff support spring of the inner plate will suppress water cavitation. Water-filled double hulls are a prevalent design for underwater warships. Studying the propagation of underwater shock wave in such structures is essential to comprehend their shock resistance. The aim of this paper is to investigate the propagation of underwater shock wave and water cavitation in a water-filled double plate. To achieve this objective, the paper establishes a Eulerian compressible fluid model that combines the isentropic single fluid model and Newton's second law. The accuracy of the numerical solver is confirmed through validation tests. The reflection and transmission characteristics of shock wave, the dynamic response of the plate, and the cavitation in external and gap water are analyzed. It also examines the effects of the supporting springs of outer and inner plates and the area density of the outer plate on the shock wave propagation and cavitation evolution. The findings indicate that the transmitted wave in the gap water is influenced by the area density and supporting spring of the outer plate. A thicker outer plate can reduce the peak value of the transmitted wave, and a stiffer supporting spring can decrease the transmitted impulse. On the other hand, if the outer plate is freestanding or softly supported, it has minimal effects on the response of the inner plate. Moreover, the water cavitation is determined by the supporting spring of the inner plate in the case of a softly supported outer plate, and the cavitation initially develops in the gap water near the inner plate before expanding towards the external water. When the supporting spring of the outer plate is stiff, it significantly reduces the occurrence of cavitation in the external water, while the cavitation in the gap water is still determined by the support spring of the inner plate. These research findings are valuable for analyzing the shock resistance of typical double-hull submarines. [Display omitted] [ABSTRACT FROM AUTHOR]