Recent Studies in Turbine Blade Cooling?

Abstract

Gas turbines are used extensively for aircraft propulsion, land-based power generation, and industrial applications. Developments in turbine cooling technology play a critical role in increasing the thermal efficiency and power output of advanced gas turbines. Gas turbine blades are cooled internally by passing the coolant through several rib-enhanced serpentine passages to remove heat conducted from the outside surface. External cooling of turbine blades by film cooling is achieved by injecting relatively cooler air from the internal coolant passages out of the blade surface in order to form a protective layer between the blade surface and hot gas-path flow. For internal cooling, this presentation focuses on the effect of rotation on rotor blade coolant passage heat transfer with rib turbulators and impinging jets. The computational flow and heat transfer results are also presented and compared to experimental data using the RANS method with various turbulence models such as k-ε, and second-moment closure models. This presentation includes unsteady high free-stream turbulence effects on film cooling performance with a discussion of detailed heat transfer coefficient and film-cooling effectiveness distributions for standard and shaped film-hole geometry using the newly developed transient liquid crystal image method.

Evolutionary numerical simulation approach for design optimization of gas turbine blade cooling channels

“…Researchers use analytical, computational and experimental methods to improve cooling techniques for gas turbine. Recent monographs focusing entirely on the gas turbine heat transfer and associated cooling technology is provided by Han et al [3,4] and Goldstein [6]. The use of multiobjective optimization in heat transfer problems is a relatively new area of focus and has been the point of interest only in recent years.…”

“…This has caused the rapid development of various methods to protect the gas turbine components. One such method is to cool these components using the highly-pressurized, compressed air of the mainstream flow that is diverted prior to the combustor section of the engine [3][4][5]. In essence, the turbine components in the hot gas path are cooled by a fraction of the compressed air (i.e., a secondary air flow) that is extracted by a cooling supply system from the compressor section of the engine (indicated by the dotted arrows in Figure 4).…”

Shape design of internal cooling passages within a turbine blade

“…Also, inner cooling is usually accompanied by film cooling, whose task is to create a thin film of cool gas (cooling air) around the profile, and, at the same time, to separate the hot working agent from the blade material. In some solutions, in order to intensify the cooling of the leading edge of the blade (usually the most thermally loaded area) impingement cooling is applied (Han, 2004). A detailed analysis of thermal and flow phenomena which take place during the cooling mechanisms mentioned above is a major computational challenge.…”

Structural Investigation on Cooling Design Influences in Rene-77 made Gas Turbine Guide Vanes

“…Increases of temperature difference between the inlet and exit of gas turbine to improve powder density as well as thermal efficiency is a nowadays trend [2,3]. Gas turbine has stationary and moving blades and that are exposed to the gas temperature approximately 1500°C.…”