Abstract
By a series of time-resolved experiments and large eddy simulations, the present work exhibits the transient behaviors and unsteady characteristics of film cooling with different trench configurations. The inevitable mainstream oscillation in turbine operation is considered, with a Strouhal number of 0.0128 and an amplitude of 0.50. The results show that: 1) The main instantaneous features are well captured by both experimental and numerical methods, and the transient behaviors of film cooling with trench design can be accurately predicted by the present large eddy simulation, even considering mainstream oscillation. 2) Without mainstream oscillation, film cooling unsteadiness is mainly caused by the temporal evolution of near-wall vortices, and the trench configurations exhibit a strong correlation on the unsteadiness level. The design with a higher trench height can evidently enhance the near-wall stability of film cooling while keeping a high time-averaged film effectiveness. 3) Film cooling unsteadiness is significantly aggravated by the mainstream oscillation. Under the present oscillation condition, the standard deviation of instantaneous film effectiveness is increased over 350.0 %, compared to the non-oscillation data. Meanwhile, the regions with high unsteadiness level are revealed with mainstream oscillation, which is mainly caused by the temporary coverage of cooling air in the target surface.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
