A Numerical Concept Study On Internal Blade Cooling in Axial Compressors

Authors

Tobias Willeke - Institute of Turbomachinery and Fluid Dynamics, Leibniz Universität Hannover
Maximilian Hellberg - Institute of Turbomachinery and Fluid Dynamics, Leibniz Universität Hannover
Joerg R. Seume - Institute of Turbomachinery and Fluid Dynamics, Leibniz Universität Hannover

Abstract

The stator blades of a three-stage axial compressor were equipped with internal cooling channels to investigate the effects of internal blade cooling on axial compressor performance and gas-turbine efficiency. For water-cooled stator blades under realistic bound ary conditions, the results from numerical simulations predict an isentropic total-to-total stage efficiency increase by 1.26 percentage points with no effect on the stage pressure ratio. In terms of overall efficiency, a multi-stage axial compressor profits from internal stator-blade cooling by a 1.45%increase. Increasing the heat exchanging surface through a higher stator solidity, this cooling benefit surpasses higher blade losses, and can be further maximized for high solidity stators. Gas-turbine efficiency, with or without recuperation is predicted to be directly proportional to the improvements in compressor efficiency.