Influence of Tip Clearance Modelling in Predictions of Aeroelastic Response in an Oscillating LPT Cascade
2012 (English)Conference paper (Refereed)
The present study investigates the influence of tip clearance modelling in predictions of the aeroelastic response in an oscillating Low-Pressure Turbine (LPT) cascade. The study was carried out through validation of different numerical models against experimental data. On the experimental side a sector cascade was used, where one of the blades was oscillated in axial bending mode. Unsteady pressure measurements were performed at several spanwise positions on the non-oscillating blades and at mid-span of the oscillating blade. On the numerical side full-scale time-marching RANS CFD simulations were performed employing models with and without tip clearance. The study showed that the model without tip clearance provides reliable result up to 70%. In the near-tip region difference induced due to the absence of tip clearance in the model amounts to about 25% of minimum stability value, relative to the nominal tip clearance model. It has also been shown that the resolution of the tip clearance mesh in spanwise direction of the gap might have a considerable impact of prediction accuracy. Imposed small variations in the tip clearance size have not led to substantial changes in predicted aeroelastic response of the cascade.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:kth:diva-128371OAI: oai:DiVA.org:kth-128371DiVA: diva2:647383
ISUAAAT 13; Tokyo, Japan, 11-14 September 2012
QC 201310022013-09-112013-09-112013-10-02Bibliographically approved