Heat transfer for gas turbine internal cooling with channel design

• Main Author: Thay, Jeremy Kai Wei
• Other Authors: Chow Wai Tuck
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Aeronautical engineering
• Online Access: https://hdl.handle.net/10356/172829
• Institution: Nanyang Technological University

With the greater need for higher inlet temperature operations of the turbine blade, enhanced cooling mechanisms have become imperative to prevent temperatures from exceeding turbine blade material limits. Achieving these elevated temperatures necessitates greater heat transfer capabilities, and one approach is through the addition of rib turbulators. While existing research predominantly focused on the single channel models, the present research explored two-channel rib cooled models. In this paper, the rib turbulator performance on the two-channel models were analysed and compared with the single channel models. Additionally, various mixed rib turbulator configurations were also tested. Computational fluid dynamics was done using ANSYS FLUENT and finite element analysis was done using ANSYS Static Structural. The results showed that the Angled V-Spline exhibited the most improvement in the maximum freestream temperature, with an increase of 10.12% over the baseline Straight rib model. However, it was observed that the fatigue cycle improvement for the Angled V-Spline was 15.73%. This was lower than the improvement for the V-Spline rib turbulator model of 26.12%. Furthermore, the magnitude of improvement in the two-channel models were comparatively smaller than the improvements seen in the single channel models. For instance, the V-Spline model had a 32.8% increase in maximum freestream temperature in the single channel model, while this increase was notably reduced to 9.58% in the two-channel V-Spline model. Nevertheless, the V-Spline model had the best overall improvement in both maximum freestream temperature and fatigue life cycles, irrespective of the single or two-channel model. The difference between the single and two-channel model was in the temperature difference between the flow entering the first and second channels, with the latter experiencing significantly higher temperatures.