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• Closed-form equations are developed for an OSWEC's pitch-pitch and surge-pitch added mass, radiation damping, and excitation forces/torques, which can be used to determine the system's response amplitude operator (RAO) and foundation loads. • The proposed model is benchmarked against numerical simulations using WAMIT and WEC-Sim; excellent agreement is found. • The flat plate assumption, inherent to the theoretical model, was examined through comparison with numerical solutions over a range of plate thickness. • A case study demonstrates the ability of the analytical model to quickly (less than one second per frequency) sweep over a domain of OSWEC dimensions, illustrating the model's utility in the early phases of design. This study presents theoretical formulations to evaluate the fundamental parameters and performance characteristics of a bottom-raised oscillating surge wave energy converter (OSWEC) device. Employing a flat plate assumption and potential flow formulation in elliptical coordinates, closed-form equations for the added mass, radiation damping, and excitation forces/torques in the relevant pitch-pitch and surge-pitch directions of motion are developed and used to calculate the system's response amplitude operator and the forces and moments acting on the foundation. The model is benchmarked against numerical simulations using WAMIT and WEC-Sim, showcasing excellent agreement. The sensitivity of plate thickness on the analytical hydrodynamic solutions is investigated over several thickness-to-width ratios ranging from 1:80 to 1:10. The results show that as the thickness of the benchmark OSWEC increases, the deviation of the analytical hydrodynamic coefficients from the numerical solutions grows from 3 % to 25 %. Differences in the excitation forces and torques, however, are contained within 12 %. While the flat plate assumption is a limitation of the proposed analytical model, the error is within a reasonable margin for use in the design space exploration phase before a higher-fidelity (and thus more computationally expensive) model is employed. A parametric study demonstrates the ability of the analytical model to quickly sweep over a domain of OSWEC dimensions, illustrating the analytical model's utility in the early phases of design. [ABSTRACT FROM AUTHOR]

• Fluid–Structure Interaction method for predicting high-speed water entry problem is • Comparison between CFD and FSI of high-speed water entry of cylinder are investigated. • Detailed description of von Mises stress over the cylinder at high entry velocity is presented. • The effects of the water-entry velocity on the cavity evolution, motion, and structural response of the cylinder are analyzed. This paper describes an investigation of the motion, structural response, and cavitation bubble evolution of a cylinder in the high-speed water entry (HSWE) process using a fluid-structure interaction (FSI) method. The effectiveness and accuracy of the FSI method are verified by comparison with experimental results available in the literature. The results show that the cylinder structure is deformed when considering the coupling effect between the fluid and the structure, and the impact load during water entry presents obvious fluctuation characteristics. Meanwhile, the von Mises stress distribution on the two end faces of the cylinder is in a ring shape and propagates as the structure deforms. Moreover, the cavitation bubble dynamics, motion and structural loads of the cylinder under different water entry velocities are investigated. The load at the initial stage is greater with the increase of the water entry velocity, which in turn leads to more significant fluctuation characteristics, thereby increasing the deformation of the structure. [ABSTRACT FROM AUTHOR]