Gas Turbine Engines: Turbine Cooling

Abstract

The advancement of gas turbine cooling has allowed engine design to greatly exceed normal material temperature limits. Cooled component design and development has consistently trended in the direction of higher heat loads, and higher through‐wall and in‐plane thermal gradients. The ultimate goals in gas turbine cooling are consistent with the thermodynamics of isentropic energy transfer in that (1) the component or some portion of it is desired to be isothermal to eliminate all internal thermal stresses, (2) the component is desired to be as hot as allowable to minimize coolant usage and inefficient energy transfers, and (3) thermal gradients from the component to the support and containment structure are desired to be minimized. In terms of the turbine system, the goal of turbine cooling is to achieve the longest component life with the least impact on engine efficiency and cost. This summary describes the means and methods, as well as the constraints, concerning the cooling of gas turbine components.