State-of-the-Art Cooling Technology for a Turbine Rotor Blade

Abstract

Effective internal and external cooling of airfoils is key to maintaining component life for efficient gas turbines. Cooling designs have spanned the range from simple internal convective channels to more advanced double-walls with shaped film-cooling holes. This paper describes the development of an internal and external cooling concept for a state-of-the-art cooled turbine blade. These cooling concepts are based on a review of literature and patents, as well as, interactions with academic and industry turbine cooling experts. The cooling configuration selected and described in this paper is referred to as the “baseline” design, since this design will simultaneously be tested with other more advanced blade cooling designs in a rotating turbine test facility using a “rainbow turbine wheel” configuration. For the baseline design, the leading edge is cooled by internal jet impingement and showerhead film cooling. The midchord region of the blade contains a three-pass serpentine passage with internal discrete V-shaped trip strips to enhance the internal heat transfer coefficient (HTC). The film cooling along the midchord of the blade uses multiple rows of shaped diffusion holes. The trailing edge is internally cooled using jet impingement and externally film cooled through partitioned cuts on the pressure side of the blade.

Research status and development trend of rotating internal cooling of a gas turbine blade

“…Though nowadays traditional serpentine cooling channel is widely used in turbine blade, the Coriolis force due to rotation still induces low heat transfer distribution on leading wall of inflow channel and trailing wall of outflow channel. To obtain higher rotor turbine inlet temperature, and achieve better heat transfer performance on leading and trailing wall, many scholars (Murray, et al 2020, Sergiy, et al 2017and Jason, et al 2017 proposed "double wall" concept, that is, a structure with thinner wall thickness compared to conventional blade wall. With thinner wall thickness, double wall blade can improve the heat transfer efficiency between coolant and hot gas due to lower thermal resistance.…”

“…Besides, Je-Chin, (2004) and Je-Chin, (2014) review recent studies in turbine blade external and internal cooling before 2004. Town, et al (2007) developed a review on the state-of-the-art cooling design for turbine blades. Wright, et al (2013) reviewed heat transfer enhancement approaches for turbine blade internal cooling and considered the rotation effect on cooling performance.…”

A Fully-Automated Framework Integrating Gaussian Process Regression and Bayesian Optimization to Design Pin-Fins

“…The pressure side of a turbine blade has a relatively higher temperature than the suction side and is, therefore, provided with additional cooling. This is accomplished by internal and external cooling that favors the pressure side of the blade, particularly in the trailing edge region [1].…”

Effect of casing purge flow on heat transfer and cooling performance of blade squealer tip for a gas turbine stage

“…Due to different pressures on both sides of blade tip, high temperature gas enters tip clearance from pressure side under pressure difference effect, forming a high heat transfer area on tip surface. 1,2 In order to effectively protect blade tip, it is necessary to set cooling channels inside turbine blade to form a coolant film near blade surface through cooling holes. In recent years, with improvement of turbine power and efficiency, blade wall is subjected to more severe heat transfer and thermal stress, which brings great challenges to turbine cooling technology.…”