The development of turbine cooling is a process that requires continuous improvements and upgrades. A gas turbine engine is a thermal device and so it is composed of a range of major and minor cooling and heating systems. Turbine cooling is just a small part of the total engine system cooling challenges (combustor system cooling, heat exchangers, casings, bores, compressor and turbine disks, bearings and gears etc.). However, effective turbine cooling consists of the greatest economic factor when it comes to engine development and repair costs, representing up to 30% of the total cost.
As a thermodynamic Brayton cycle, the performance of the gas turbine engine is influenced by the turbine inlet temperature, and the raise of this temperature can lead to better performance and more efficient machines. Current advancements in the development of cooling systems allows most modern gas turbines to operate in temperatures much higher than the material melting point. Of course nothing would have been possible without the parallel development of advanced materials for structural components as well as advances in computing resources and consequently in aerodynamic design, prognostic and health monitoring systems and lifing processes. In particular, as far as the lifing of the machine is concerned, the high pressure (HP) turbine containing the most advanced high temperature alloys and associated processing methods, as well as the combustor which represents the key components that have limited life and tend to strictly dictate the cycles of operation and the allowable time on the wing.
At SoftInWay we follow the engineering needs and we lead the turbomachinery software development market. For that reason we accepted the challenge to model cooled gas turbines and other cooling flows, especially in an integrated fashion taking into account the full aerodynamics of the components as well as the full thermodynamics of the cycle. AxSTREAM NET™ gives the user the possibility to design advanced and complex gas turbine cooling flow systems by representing thermal-fluid systems through networks of nodes and flow elements. The non-necessity for 3D geometry allows for its use before finalizing the blades geometry while keeping good accuracy in the results in a very short computation time. This helps considerably reduce the iterations time required to optimize aerodynamic cooling losses and machine performances. For more information do not hesitate to ask our team and check out our most recent webinar to get a clear view of an automatic process to determine joint working conditions of turbine and compressors components with entire secondary flow (cooling) system to improve the off-design performance of a gas turbine unit. View the recording here.
Bunker RS. Evolution of Turbine Cooling. ASME. Turbo Expo: Power for Land, Sea, and Air, Volume 1: Aircraft Engine; Fans and Blowers; Marine; Honors and Awards ():V001T51A001. doi:10.1115/GT2017-63205.