Estimation of the Velocity of Hard Foreign Object Impacting the Engine Blade: Preliminary Study

In the present study, based on kinetic energy theorem and Newton’s second law, the velocity equation of the hard foreign object was derived by taking the engine inlet as reference frame. Taking a certain type of aircraft as an example, the factors that influence the impact velocity of foreign objects were discussed at 100% design rotating speed of the engine. It is observed that the velocity of the foreign object is not only related to the dimension, shape, material, and impact location of the foreign object, but also related to the length of the engine inlet as well as the working state of the engine. The proposed method can be used for estimating the impact velocity in FOD tests by taking into account working state of the engine.