At cruise condition, the flow around a typical passenger aircraft is characterised by the presence of shock waves, which interact with the boundary layers developing over the wings. The consequence is the occurrence of large scale unsteadiness such as high-amplitude self-sustained shock movements, known as shock buffet. This can have a significant influence on the aircraft and often leads to undesirable effects such as loss of performance or structural damage.
Buffet is an important factor limiting the flight envelope of modern transport aircraft and there is an increasing interest in delaying buffet offset. The practical difficulties of modelling buffet have been known for many years and much research has been undertaken with ever more sophisticated modelling tools to analyse the phenomenon. More recently attempts have been made to reduce the effect of buffet by active or passive means. This work programme aims to significantly improve our understanding of the underlying flow physics and to develop techniques to predict buffet in a practical time-scale for industrial aircraft design.
The objectives of the BuColic project are to advance the state of the art in areas including:

• Increased understanding of the flow physics of 3D transonic wing buffet;

• Increased understanding of the parameters that affect 3D buffet;

• Develop an industrialised CFD method able to predict buffet for routine use during in developing control devices for wing design;

• Improved understanding of buffet control devices to improve performance of next generation wings.

The DLR TAU code will be used in URANS and Detached Eddy Simulation modes to make time-accurate simulations aiming at reproducing the buffet phenomenon. A central computing cluster will be accessed for these computationally demanding calculations. The approach proposed for the CFD calculations is to demonstrate and evaluate the use of the well established DLR TAU code for the wing-body test case, including validation against the experimental measurements. Buffet will be investigated considering many combination of angles of attack and Mach numbers, with particular attention to the onset condition. Then, flow control with vortex generators will be incorporate into the simulation, fully resolved in the mesh and also with simplified treatment of the boundary conditions to reduce computational cost. The development of a model reduction approach as a potential design tool will also be considered.

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