Simulation of Check Valve Flapper-Housing Impact Using LS-DYNA Fluid-Structure Interaction

The flapper of a check valve in the aircraft air management system may hit the housing with a very high speed due to the sudden pressure differential caused by duct rupture, which may lead to the damage of the flapper. This event ®can be simulated using transient dynamic finite element tool, such as LS-DYNA . However, the flapper impact speed usually is unknown. The current study is focused on solving for the impact speed with the developed Fluid-Structure Interaction technology in LS-DYNA, using Arbitrary Lagrangian-Eulerian (ALE) formulation. With the aid of a concept of “Source”, “Moving Air”, and “Sink” for the ALE model, which represent the conditions of constant cabin pressure, airflow interacting with the flapper, and non-pressurized ambient environment, respectively, the proposed method successfully simulated the check valve fluid-structure interaction behavior. The predicted impact speed has an excellent agreement with the test. The developed methodology is accurate, easy to use, and applicable to all check valves regardless of size, material, and pressure differential.