Compared with a straight blade, a unique compressor blade integratedforward-swept and positive-curved stacking line is studied experimentally. Aerodynamic parameters ofthe two cascades are measured by a five-hole prob...Compared with a straight blade, a unique compressor blade integratedforward-swept and positive-curved stacking line is studied experimentally. Aerodynamic parameters ofthe two cascades are measured by a five-hole probe at different positions and ink trace flowvisualization is conducted on blade surfaces. The result shows that the swept-curved cascade haslower endwall loss and higher midspan loss as compared with the straight cascade. However, lowerloss is accompanied with lower diffusion factor. Opposite 'C' shape static pressure distribution isestablished on the suction surface of the swept-curved blade, which is helpful for avoiding theaccumulation of low energy fluid in the endwall corner region. Anyhow the studies support theconclusion that the swept-curved blade conduces to not only the reduction of overall loss but alsothe improvement of stable operation in the endwall corner region.展开更多
The effects of blade lean and vortex design on the aerodynamics of a turbine entry nozzle guide vane （NGV） are considered using computational fluid dynamics. The aim of the work is to address some of the uncertainti...The effects of blade lean and vortex design on the aerodynamics of a turbine entry nozzle guide vane （NGV） are considered using computational fluid dynamics. The aim of the work is to address some of the uncertainties which have arisen from previous studies where conflicting results have been reported for the effect on the NGV. The configuration was initially based on the energy efficient engine turbine which also served as the validation case for the computational method. A total of 17 NGV configurations were evaluated to study the effects of lean and vortex design on row efficiency and secondary kinetic energy. The distribution of mass flow ratio is introduced as an additional factor in the assessment of blade lean effects. The results show that in the turbine entry NGV, the secondary flow strength is not a dominant factor that determines NGV losses and therefore the changes of loading distribution due to blade lean and the associated loss mecha- nisms should be regarded as a key factor. Radial mass flow redistribution under different NGV lean and twist is demonstrated as an addition key factor influencin~ row efficiency.展开更多
文摘Compared with a straight blade, a unique compressor blade integratedforward-swept and positive-curved stacking line is studied experimentally. Aerodynamic parameters ofthe two cascades are measured by a five-hole probe at different positions and ink trace flowvisualization is conducted on blade surfaces. The result shows that the swept-curved cascade haslower endwall loss and higher midspan loss as compared with the straight cascade. However, lowerloss is accompanied with lower diffusion factor. Opposite 'C' shape static pressure distribution isestablished on the suction surface of the swept-curved blade, which is helpful for avoiding theaccumulation of low energy fluid in the endwall corner region. Anyhow the studies support theconclusion that the swept-curved blade conduces to not only the reduction of overall loss but alsothe improvement of stable operation in the endwall corner region.
基金the support of Cranfield University and China Aviation Powerplant Research Institute of AVIC
文摘The effects of blade lean and vortex design on the aerodynamics of a turbine entry nozzle guide vane （NGV） are considered using computational fluid dynamics. The aim of the work is to address some of the uncertainties which have arisen from previous studies where conflicting results have been reported for the effect on the NGV. The configuration was initially based on the energy efficient engine turbine which also served as the validation case for the computational method. A total of 17 NGV configurations were evaluated to study the effects of lean and vortex design on row efficiency and secondary kinetic energy. The distribution of mass flow ratio is introduced as an additional factor in the assessment of blade lean effects. The results show that in the turbine entry NGV, the secondary flow strength is not a dominant factor that determines NGV losses and therefore the changes of loading distribution due to blade lean and the associated loss mecha- nisms should be regarded as a key factor. Radial mass flow redistribution under different NGV lean and twist is demonstrated as an addition key factor influencin~ row efficiency.
