CFD Analysis of Matrix Cooling Method in Gas Turbine Blades

Abstract

Gas turbines are extensively in use for aircraft propulsion, land-based power generations, and various industrial applications. Thermal efficiency and the power output of a gas turbine increases with increase in turbine rotor inlet temperature (RIT). The current RIT level in many advanced gas turbines is far above the melting point of the used blade material. Therefore, along with development in high temperature material, a more sophisticated cooling scheme must be developed for continuing the safe operation of gas turbines with high performances. Gas turbine blades can be cooled internally as well as externally. This paper is focused on the internal cooling of turbine blades and vanes of a gas turbine. Internal cooling can be achieved by passing coolant through various enhanced serpentine passages inside the blade and extracting heat from outside of the blades. Jet impingement, matrix cooling, rib turbulator, dimple and pin fin cooling are utilized as the methods of internal cooling, which are presented in various articles. Due to the different enhancement in heat transfer and in pressure drop, they are being used in specific part of the blades and the vanes on a gas turbine. The matrix cooling, also known as lattice-work or vortex cooling provides a good strength to blades by the layers of ribs which intersect each other from the opposite wall. A significant increase in the heat transfer is obtained due to an increase in heat transfer area, impinging and in swirling flows (which helps to promote turbulence), induced by the geometry of the matrix cooling channels.