Research on the Water Entry of the Fuselage Cylindrical Structure Based on the Improved SPH Model

Abstract

During aircraft landing on water, the intense impact load may lead to significant local deformation of the fuselage skin. Ensuring the aircraft’s integrity and reliability is of paramount importance. This paper investigates the fuselage skin’s dynamic response during water entry. In the simulation of complex water entry problems, the smoothed particle hydrodynamics (SPH) method can fully leverage the advantages of the particle method. However, the traditional SPH method still suffers from the drawbacks of tensile instability, significantly affecting the computational accuracy. Therefore, this paper first introduces the improved SPH model addressing fluid and solid tensile instability issues. Furthermore, the Riemann-based contact algorithm at the fluid–solid interface is also demonstrated. Based on the above improved SPH model, the simulation of water entry of the elastic cylinder is performed to validate the efficacy of the improved SPH model. Then, the dynamic response characteristics of elastic fuselage skin and the skin–stringer–floor–column structure when it enters the water are analyzed, including the deformation features and slamming force. Lastly, based on the presented damage model, a study is conducted on the water entry of the metallic elastic–plastic skin–stringer–floor–column structure, analyzing the locations of failure and providing guidance for the structural safety design of engineering.

Research of Slamming Load Characteristics during Trans-Media Aircraft Entry into Water

“…Wang et al [19] used the VOF method and overset mesh to carry out a numerical simulation of the water entry of an AUV under different conditions, and explored the change rule of the trajectory of the AUV. Wang et al [20] improved the SPH model and simulated the elastic cylinder water entry process, verified the validity of the improved SPH model, and analyzed the dynamic response characteristics such as deformation and impact force when the elastic structure enters water. In summary, scholars in the past have carried out a lot of research on the problem of water entry of objects through experiments, theoretical analysis, and numerical simulation.…”