Considering the Effects of Turbine Blade Cooling on Engine Performance Estimation
Paper i proceeding, 2017
In gas turbines, a way to improve the engine performance is by increasing the Turbine Inlet Temperature (TIT). However, increasing TIT causes an increase in heat load of turbine components. A limit in the performance improvement is imposed by the permissible metal temperature. Engine running above the melting point of material might be achieved only by cooling turbine components or using Thermal Barrier Coating (TBC). This thermal management must be done to ensure safe and durable engine operation. The most common method to cool turbine components is bleed a portion of the compressor airflow and inject it on blades and disks. Unfortunately, the extraction has an adverse effect on engine performance compared with engine without bleed. In this paper, the cooling effects on engine performance estimation at preliminary design was analyzed. The engine configuration used in the study is a turboshaft – single spool gas turbine engine. The coolant parameters are estimated using the method developed by Young and Wilcock. The results showed that there is a marked difference on performance for uncooled and cooled turbine blades, highlighting the importance in considering the cooling on performance estimation since design preliminary phase. Ignoring the cooling in evaluation can cause up to 15% difference in net specific work.