Predicting film cooling performance of trailing–edge cutback turbine blades by detached–eddy simulation

Effendy, Marwan; Yao, Yufeng; Yao, Jun; Marchant, Denis R.

Abstract

This paper describes numerical studies of the film cooling performance of cutback trailing-edge gas turbine blades using the detached eddy simulation (DES) approach, in order to improve results obtained by industry standard steady RANS and unsteady RANS (URANS). An experimental configuration of blade cooling slot with two rows of long ribs at three different blowing ratios (M = 0.5, 0.8, 1.1) are investigated and three aforementioned numerical approaches based on the same SST k-ω turbulence model are adopted. Simulation flow conditions follow experimental and numerical studies previously done by other researchers. At a low blowing ratio M = 0.5, current numerical predictions have shown that DES results are in good agreement with available experimental measurement of film cooling effectiveness along the trailing-edge cutback surface, whereas both RANS and URANS largely over-predict in the near and far wake regions. At a moderate blowing ratio M = 0.8, DES slightly over-predicts the film cooling effectiveness after a nondimensional streamwise location x/H > 8 (with H denotes the slot height), whereas at a high blowing ratio M = 1.1 it under-predicts after x/H > 5. The effect of lip thickness has also been studied and it was found that a thinner lip thickness t/H = 0.5 (with t denotes the lip thickness) produces an adiabatic film cooling effectiveness of near unity along the trailing-edge cutback surface, indicating that there is need to reduce the lip thickness to achieve a higher level of cooling effectiveness, without compromising other constraints such as blade structure and loadings.

• Presentation Conference Type: Conference Paper (published)
• Conference Name: 52nd Aerospace Sciences Meeting
• Start Date: Jan 13, 2014
• End Date: Jan 17, 2014
• Acceptance Date: May 1, 2013
• Publication Date: Jan 10, 2014
• Deposit Date: Jun 23, 2021
• Volume: AIAA 2014-0279
• ISBN: 9781624102561
• DOI: https://doi.org/10.2514/6.2014-0279
• Public URL: https://uwe-repository.worktribe.com/output/7487703