Heat transfer in the trailing region of gas turbines - A state-of-the-art review

Highly efficient gas turbines are beneficial for improving the energy structure, reducing carbon dioxide emissions and protecting the Earth's environment. A highly efficient gas turbine means a higher inlet temperature and requires a more efficient cooling structure. Due to the limitations of aerodynamics, structure and strength, cracks, fractures and ablation easily form at the trailing edge of gas turbines. Thus, it is vital to enhance the heat transfer in the trailing edge of gas turbines. In practical applications, internal cooling structures (pin fins, latticework ducts) and film cooling are used simultaneously. In addition, some innovative cooling structures have been proposed, such as dimples/protrusions, labyrinth channels and so on. Research progress on turbine trailing edge cooling structures is presented in this paper. For pin finned duct, the heat transfer and flow structure characteristics are introduced for single rows, multirows, static and rotating conditions. Investigations on latticework ducts are quite inadequate. Therefore, only the main flow and heat transfer characteristics are shown in this paper. For film cooling at the trailing edge, experimental results and numerical results are introduced. Finally, some suggestions for heat transfer research in the trailing edge region are proposed.

Automated summary

Highly efficient gas turbines are crucial for improving energy structures and reducing carbon emissions, but issues at the trailing edge call for enhanced heat transfer measures. Research focuses primarily on pin finned ducts, with limited investigations on latticework ducts. Additional cooling structures and innovative designs are being explored for better efficiency.