Implementation of Transitional Laminar SeparationBubbles in a Navier-Stokes Code
Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Laminar separation bubbles evolve on laminar wing at low Reynolds number.These bubbles have especially been observed on winglets or on wings with flapsor slats. They can stretch up to 30% chord, taking them into account is crucialsince their presence greatly modifies the forces acting on a wing. However, theestablishment of a model is extremely complex and many researches are stillundertaken on this subject. The aim of this work is to achieve automation ofdetecting and taking into account long bubbles in the Navier -Stokes code ofDassault Aviation named Aether. The key issue is the proper detection of thetransition position inside the bubble. This detection is possible by performing alinear stability calculation, but this method is not very robust in this case andvery costly in computation time, as conventional methods are not practicable inthe presence of separation. Finally, the chosen method uses a boundary layercode to predict the position of separation, then a criterion involving local integralquantities to determine the intermittent transition area. This method has beentested for various 2D airfoils and provided quite satisfactory results.
Place, publisher, year, edition, pages
2014. , 13 p.
TRITA-AVE, ISSN 1651-7660 ; 2014:05
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-159273OAI: oai:DiVA.org:kth-159273DiVA: diva2:784014