Navigation path

Decrease textIncrease textDividerPrint versionRSSDivider

Fundamental Research on Aircraft Wake Phenomena


This project is the continuation of a recent effort, on a European level, to characterise, understand and control aircraft wake turbulence. Aircraft in flight leave behind large-scale swirling flows (vortices), which can represent a significant hazard to following aircraft, and therefore are of great importance for practical applications concerning air transport safety and capacity. The project focuses on unresolved fundamental aspects of wake dynamics, thus complementing the existing, mostly empirical knowledge obtained in previous projects.

Project objectives

The main objective is to gain new knowledge about open issues of vortex dynamics relevant to aircraft wakes, and to provide a more systematic description than previously achieved of the phenomena involved in aircraft wake dynamics. These fundamental developments are necessary to achieve major advances in this domain, in view of a successful application of existing or future strategies for wake characterisation, prediction and alleviation. The topics include the precise role of vortex instabilities on wake decay, the influence of engine jets and fuselage wakes, and ground effects in wake evolution, relevant to the airport environment.

Vortices in the wake of a civil transport aircraft
Vortices in the wake of a civil transport aircraft

Description of the work

The FAR-Wake project contains four major Work Packages. In the first, studies related to the dynamics and instabilities of one or several vortices are considered. The second Work Package introduces additional features: jets from engine exhaust, and wakes (axial velocity deficits) generated by the fuselage or other wing elements. The third Work Package considers wake evolution near the ground, with special emphasis on the prediction of wake behaviour in this situation. The fourth Work Package deals with synthesis and assessment.

In the majority of cases, emphasis is put on the study of simplified geometries and generic vortex configurations, which facilitates the use of different complementary approaches. In support of new experimental and numerical investigations, theoretical/analytical treatment is applied, with the aim of obtaining a systematic description and comprehension of the phenomena. Furthermore, extensive use is made of results and data from previous projects or available databases. The confrontation and comparison of different sets of results will validate the findings and make the description of the studied phenomena more complete. At the end, an important effort will be made to provide a synthesis of all the new fundamental results obtained, and to assess their relevance for the wake turbulence problem for real aircraft. Certain features found to be promising for the acceleration of wake decay, such as flows with multiple wake vortices, will be analysed and tested in a realistic configuration, using numerical simulations and experiments in a large-scale towing tank facility.

Expected results

This project will generate systematic results and physical understanding concerning previously unresolved issues related to aircraft trailing wakes, including the role of vortex instabilities, the influence of engine jets and fuselage wakes, and ground effects. This will create a solid knowledge base for future applications aiming at the reduction of wake turbulence hazards. Concerning ground effects, the project will in addition produce improved tools for the real-time prediction of wake vortex behaviour, to be used in the domain of Air Traffic Management.

Long- and short-wave instabilities in a vortex pair
Long- and short-wave instabilities in a vortex pair