Enhanced Aircraft Wake Decay Under Crosswind Conditions

Abstract

The starting vortex generated by air blowing from the ground destroys the aircraft wake vortex within a short period of time. Thus, air blowing might shorten flight separation and promote airport operating efficiency. A crosswind is a common phenomenon affecting airplane landing, and it can greatly affect air blowing. In this paper, a large-eddy simulation was used to study the interference exerted by different blowing zones on a wake vortex. The best-performing blowing strategy was estimated by ascertaining the relationship between the blowing zone aspect ratio and the corresponding starting vortex strength. It was found that, without the crosswind, the blowing effect remained almost constant for an aspect ratio of between one and 16. A passive tracer released from the different blowing zones proved that the mechanisms of enhanced vortex decay, with or without crosswind, were identical. However, the results showed that crosswind caused asymmetrical and reduced artificial wake decay enhancement. When the crosswind was imposed, the development of the upwind vortex was sensitive to the aspect ratio, and the blowing zone with an aspect ratio of 16 showed the best performance.