Bird modelling for simulation of bird strikes

As proved in the conducted analyses, one of the factors, which, to a large degree, exerts a negative influence on flight safety, is a potential possibility of a collision of an aircraft with birds, in particular at an airfield or in its vicinity [12, 16]. Various parts of an aircraft are subjected to damage. It appears that damage to the engine as well as penetration of the windshield is extremely dangerous. The consequence of a bird falling into the engine can be engine shutting down [6, 21], whereas penetrating the canopy can cause a serious injury to the pilot, making him unable to continue piloting an aircraft. The analysis of the literature of the object of study [7] shows that the most damage of the windshield occurs in the category of aircraft and small helicopters, whose certification requirements were not specified in this case [1, 19]. It should be remembered that apart from the compulsory experimental strength tests, conducted in laboratory conditions in order to meet certification requirements, there exist various theoretical methods, which are realized based on proper mathematical modelling of the strike event [5, 10]. Therefore, due to lack of certification requirements for the category of normal aeroplanes and small helicopters and a high degree of damage, especially to the cockpit canopy, it seems justified to conduct simulation of the strike impact by means of proper software. In order to perform the modelling in question, it is necessary to select a proper bird model and a suitable simulation method, including appropriate software. Based on the available literature devoted to the subject, there are several methods of modelling a bird shape. Investigations exploit various geometrical figures in order to model the bird shape, the most common one being a cylinder, an ellipsoid and a cylinder with hexagonal endings [10]. The aim of this article is to analyse the selected methods in order to choose one of them for further research connected with the simulation of bird-strike events into a cockpit windshield of selected aircraft.