Dynamic Aircraft Wake Separation Based on Velocity Change

Abstract

Traditional research on static wake-vortex reduction usually considers only the influence of external environmental factors, while ignoring the dynamic change in an aircraft’s flight state. In order to solve this problem, this paper proposes a method to reduce separation using dynamic wake information based on changes in flight velocity. Firstly, relying on the wake-vortex generation and dissipation model, the initial circulations and dissipation parameters of the wake vortex at different aircraft velocities are calculated. Then, the complete evolution process of the wake vortex generated by different types of aircraft at different velocities is analyzed, and the evolution law of a wake vortex with changing velocity is obtained. Afterwards, according to the actual aerodynamic shape of CRJ-900, the aerodynamic model for CRJ-900 when it encounters a wake vortex is established. The situation of an CRJ-900 encountering a wake vortex under TBS is analyzed, which proves that TBS is safe and has a certain reduction potential. Then, taking the rolling moment coefficient as the safety index, the minimum safe separations at different velocities are calculated. Finally, a simulation for the separation reduction based on a dynamic wake vortex is carried out. Compared with the static wake-based separation, the dynamic wake-based separation technology can greatly reduce the aircraft separation requirements while ensuring the operation safety. The final simulation results show that the dynamic separation reduction in CRJ-900 following a medium and heavy aircraft can reach 44.3% and 51.6%, respectively.