Numerical Simulation Research on Separation Process of Jettisoned FDR from Civil Aircraft †.

The safety of Jettisoned FDRS in the process of separation from an aircraft is a key factor in designing Jettisoned FDRs and enabling them to pass airworthiness certification and be widely used in civil aircraft. The separation process of Jettisoned FDR installed on NASA Common Research Model is studied by the simulation method based on anisotropic unstructured hybrid grid and overset grid technology coupled with the rigid body 6-DOF equation. First, the numerical simulation accuracy of software under same simulation method is verified by WPFS standard model. Then, according to the three main aerodynamic parameters, including incoming Mach number, angle of attack α and sideslip angle β, 10 conditions including standard condition are designed and the separation process of recorder is simulated numerically. The simulation obtained the movement of Jettisoned FDRs in 6 degrees of freedom relative to the body coordinate system in different operating conditions during the separation process and confirmed that Jettisoned FDRs can be safely separated under these operating conditions. Finally, combined with the standard operating condition, the impact of three parameters' changes on recorder's 6 degrees of freedom motion and the time required to complete separation are analyzed, and conditions to ensure the safe separation of Jettisoned FDRs are summarized according to the requirements of airworthiness terms. [ABSTRACT FROM AUTHOR]