Numerical Analysis for the Safe Range of AOA under Bird Impact on Unmanned BWB

摘要

In case of UAV (unmanned aerial vehicle), it has critical unsafe factor comparing airplane, caused by electronic control and light weight. Electronic control could make the critical failure unexpected situation and light weight could happen large pinch momentum. Most of bird-strike has been focused on not the change of momentum but damage of thrust mechanism. However, in UAV case, due to relative light weight AOA (angle of attack) could be changed until certain stall point. The purpose of this study was to suggest of safe flying condition. This study used the BWB (blended wing body) aircraft which is brand-new type of aircraft and many researchers have tried to design as UAV. In this study, the process was proceeded four steps which are analyzing characteristic of aerodynamics in determine AOA, calculating the momentum varying AOA, finding the change of AOA after the impact each case using momentum analysis, and with the analysis of specific stall angle, suggesting safety AOA after impact. This study considered that when force of restitution was equal to pinch moment, change of AOA would be stopped. This study used k-e model to find characteristic of aerodynamics and LS-DYNA to figure out the amount of momentum