This paper presents the study of the influence of channel geometry on the flow structure and heat transfer, and also their correlations on all the walls of a radial cooling passage model of a gas turbine blade. The in...This paper presents the study of the influence of channel geometry on the flow structure and heat transfer, and also their correlations on all the walls of a radial cooling passage model of a gas turbine blade. The investigations focus on the heat transfer and aerodynamic measurements in the channel, which is an accurate representation of the configuration used in aeroengines. Correlations foi： the heat transfer coefficient and the pressure drop used in the design of internal cooling passages are often developed from simplified models. It is important to note that real engine passages do not have perfect rectangular cross sections, but include a comer fillets, ribs with fillet radii and a special orientation. Therefore, this work provides detailed fluid flow and heat transfer data for a model of radial cooling geometry which has very realistic features.展开更多
The present investigation analyzes the effects of major geometrical modifications to the interior of a convectioncooled gas turbine rotor blade. The main focus lies on the flow of the leading edge channels and the imp...The present investigation analyzes the effects of major geometrical modifications to the interior of a convectioncooled gas turbine rotor blade. The main focus lies on the flow of the leading edge channels and the impact on theheat transfer. An experimental approach is performed with flow visualization via paint injection into water. Alsonumerical calculations are carried out in two sets, on the one hand water calculations accompanying the experimentsand on the other hand conjugate heat transfer calculations under realistic engine conditions. The latter calculationsare still ongoing delivering preliminary results.Five geometry configurations are investigated, three of them with differing turbulator arrangements in the leadingedge channels. The operating point of the base configuration is set to Re = 50,000 at the inlet while for the modifiedgeometries the pressure ratio is held constant compared to the base.Among several investigated configurations one could be identified that leads to a heat transfer enhancement inone leading edge channel 7 % larger compared to the base.展开更多
In recent years, the correlation coefficient of pressure data from the same blade passage in an axial compressor unit has been used to characterize the state of flow in the blade passage. In addition, the correlation ...In recent years, the correlation coefficient of pressure data from the same blade passage in an axial compressor unit has been used to characterize the state of flow in the blade passage. In addition, the correlation coefficient has been successfully used as an indicator for active control action using air injection. In this work, the correlation coefficient approach is extended to incorporate system identification algorithms in order to extract a mathematical model of the dynamics of the flows within a blade passage. The dynamics analyzed in this research focus on the flow streams and pressure along the rotor blades as well as on the unsteady tip leakage flow from the rotor tip gaps. The system identification results are used to construct a root locus plot for different flow coefficients, starting far away from stall to near stall conditions. As the compressor moves closer to stall, the poles of the identified models move towards the imaginary axis of the complex plane, indicating an impending instability. System frequency data is captured using the proposed correlation based system identification approach. Additionally, an oscillatory tip leakage flow is observed at a flow coefficient away from stall and how this oscillation changes as the compressor approaches stall is an interesting result of this research. Comparative research is analyzed to determine why the oscillatory flow behavior occurs at a specific sensor location within the tip region of the rotor blade.展开更多
基金funding from the European Union Seventh Framework Programme(FP7/2007-2013)under Grant Agreement No.233799(ERICKA)
文摘This paper presents the study of the influence of channel geometry on the flow structure and heat transfer, and also their correlations on all the walls of a radial cooling passage model of a gas turbine blade. The investigations focus on the heat transfer and aerodynamic measurements in the channel, which is an accurate representation of the configuration used in aeroengines. Correlations foi： the heat transfer coefficient and the pressure drop used in the design of internal cooling passages are often developed from simplified models. It is important to note that real engine passages do not have perfect rectangular cross sections, but include a comer fillets, ribs with fillet radii and a special orientation. Therefore, this work provides detailed fluid flow and heat transfer data for a model of radial cooling geometry which has very realistic features.
基金supported by the AG Turbo with funds of the Federal Ministry of Eco- nomics and Technology BMWi (FKZ 0327715G)
文摘The present investigation analyzes the effects of major geometrical modifications to the interior of a convectioncooled gas turbine rotor blade. The main focus lies on the flow of the leading edge channels and the impact on theheat transfer. An experimental approach is performed with flow visualization via paint injection into water. Alsonumerical calculations are carried out in two sets, on the one hand water calculations accompanying the experimentsand on the other hand conjugate heat transfer calculations under realistic engine conditions. The latter calculationsare still ongoing delivering preliminary results.Five geometry configurations are investigated, three of them with differing turbulator arrangements in the leadingedge channels. The operating point of the base configuration is set to Re = 50,000 at the inlet while for the modifiedgeometries the pressure ratio is held constant compared to the base.Among several investigated configurations one could be identified that leads to a heat transfer enhancement inone leading edge channel 7 % larger compared to the base.
基金supported by a generous grant from the National Natural Science Foundation of China on project No.51306178
文摘In recent years, the correlation coefficient of pressure data from the same blade passage in an axial compressor unit has been used to characterize the state of flow in the blade passage. In addition, the correlation coefficient has been successfully used as an indicator for active control action using air injection. In this work, the correlation coefficient approach is extended to incorporate system identification algorithms in order to extract a mathematical model of the dynamics of the flows within a blade passage. The dynamics analyzed in this research focus on the flow streams and pressure along the rotor blades as well as on the unsteady tip leakage flow from the rotor tip gaps. The system identification results are used to construct a root locus plot for different flow coefficients, starting far away from stall to near stall conditions. As the compressor moves closer to stall, the poles of the identified models move towards the imaginary axis of the complex plane, indicating an impending instability. System frequency data is captured using the proposed correlation based system identification approach. Additionally, an oscillatory tip leakage flow is observed at a flow coefficient away from stall and how this oscillation changes as the compressor approaches stall is an interesting result of this research. Comparative research is analyzed to determine why the oscillatory flow behavior occurs at a specific sensor location within the tip region of the rotor blade.
