Innovative Cyclone Cooling Scheme for Gas Turbine Blade: Thermal-Hydraulic Performance Evaluation

Abstract

The potential of currently used internal blade cooling technologies is nearly exhausted and the further improvements in the cooling efficiency can only be achieved through increases either in the air flow rate bled from the compressor or through reductions in the cooling passage size. This however results in the decrease of the gas turbine efficiency, and can cause dirt blockage problems. Several research programs were recently launched in the USA, UK and Germany to explore some novel concepts and to study innovative cooling techniques with improved parameters. One of them is an internal cyclone cooling technique, based on generation of swirl flow in blade cooling passages. Several designs of cyclone cooling, based on a two cooling passage configuration have been proposed and investigated in the USA and the former USSR over the last ten years, and these investigations have already demonstrated the superior heat transfer rate compared with conventional cooling techniques. The novel three passage serpentine cyclone cooling scheme was proposed by the authors recently in which coolant moves successively through three cooling passages in two of those swirling flow is generated. New experimental data and the experimental correlations regarding heat transfer and fluid flow parameters in passages of an innovative cyclone cooling scheme have been obtained. The diagram of thermal-hydraulic performance is presented and comparison with conventional cooling techniques is given. The three passage cyclone cooling scheme has demonstrated the high rate of heat transfer and thermal-hydraulic performance at acceptable energy losses.