TOBLERINE - Transition Onset in Boundary Layer Experiments with Receptivity IN Examination

Computational Fluid Dynamics (CFD) is widely used in both academic research and by technology companies for product design and development.

In CFD complex physics is being modeled, which implies that the accuracy of the calculations is not improved by increasing the grid resolution as in direct numerical simulations (DNS).

Being able to predict the location where the flow transitions from laminar-to-turbulent has been recognized as a key factor in many engineering disciplines since it directly affects mixing processes, skin-friction drag, and heat transfer.

Despite this, there are limitations of the physical understanding.Free-stream turbulence (FST) gives, undoubtedly, rise to the most complicated boundary-layer transition scenario. The FST is present everywhere in the free stream, but changes characteristics with the downstream distance.

This implies that the actual forcing by the FST on the boundary layer changes gradually, which makes it an intricate receptivity problem.In TOBLERINE we will experimentally address the receptivity problem in wind tunnel campaigns using an innovative experimental setup and state-of-the-art measurement systems.

By listening at the flow, with over 200 microphones simultaneously, we can quickly determine whether the flow is laminar or turbulent.

The required amount of data to find correlations for modelling the physical transition process can only be obtained from experiments since DNS is still far too expensive for parameter variation studies.