Calculation and analysis of the simplified hazard area of the wake vortex based on the rolling moment coefficient

DOI:	10.11809/bqzbgcxb2023.03.020
Keywords:	wake encounter; aerodynamic model; rolling moment coefficient; simplified hazard area; wake interval
Abstract:	In order to further enhance flight efficiency under the premise of ensuring safety, this paper introduces a method for the delineation of a simplified hazard area of wake vortexes, and flight safety can be achieved by avoiding these areas. Based on an aerodynamics model in which an aircraft encounters a wake vortex, this paper firstly calculates the rolling moments of the aircraft encountering the wake vortex at different positions.After that, with the rolling moment coefficient being the safety index, the regions with a value higher than the limit of the rolling moment are enveloped, and the simplified hazard area of the wake vortex is delineated.Finally, considering the volume of the rear engine itself, the hazard probability of encountering the wake vortex is calculated and analyzed by combining the evolution and motion characteristics of the wake vortex as well as different crosswind conditions.The results show that the lateral and vertical boundaries of this simplified hazard area decrease with the evolution of the wake vortex, and the far vortex phase decreases more rapidly than the near vortex phase. For the wake vortex with an initial circulation of 500 m2/s, the rear engine can completely escape the simplified hazard area under the sinking action of the wake vortex for about 11.6 s.The side wind at 4.48 m/s can have the same effect on the side of the simplified hazard area, and the crosswind with a higher speed can further shorten the time for the rear engine to completely escape this area.
Published:	2023-03-28
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