This study is aimed at using blade 3-D optimization to control corner flows in the high through-flow fan/booster of a high bypass ratio commercial turbofan engine. Two kinds of blade 3-D optimization, end-bending and ...This study is aimed at using blade 3-D optimization to control corner flows in the high through-flow fan/booster of a high bypass ratio commercial turbofan engine. Two kinds of blade 3-D optimization, end-bending and bow, are focused on. On account of the respective operation mode and environment, the approach to 3-D aerodynamic modeling of rotor blades is different from stator vanes. Based on the understanding of the mechanism of the corner flow and the consideration of intensity problem for rotors, this paper uses a variety of blade 3-D optimization approaches, such as loading distribution optimization, perturbation of departure angles and stacking-axis manipulation, which are suitable for rotors and stators respectively. The obtained 3-D blades and vanes can improve the corner flow features by end-bending and bow effects. The results of this study show that flows in corners of the fan/booster, such as the fan hub region, the tip and hub of the vanes of the booster, are very complex and dominated by 3-D effects. The secondary flows there are found to have a strong detrimental effect on the compressor performance. The effects of both end-bending and bow can improve the flow separation in corners, but the specific ways they work and application scope are somewhat different. Redesigning the blades via blade 3-D optimization to control the corner flow has effectively reduced the loss generation and improved the stall margin by a large amount.展开更多
Leading edge recambering is applied to the cantilevered stator vanes in a 2-stage compressor in this paper. Differentcurving effects are produced when the end-bend stator vanes are stacked in different ways. Stacking ...Leading edge recambering is applied to the cantilevered stator vanes in a 2-stage compressor in this paper. Differentcurving effects are produced when the end-bend stator vanes are stacked in different ways. Stacking on theleading edge induces a positive curving effect near the casing.When it is stacked on the centre of gravity, a negativecurving effect takes place. The numerical investigation shows that the flow field is redistributed when theend-bend stators with leading edge stacking are applied. The variations in the stage matching for the mainstreamand near the hub have an impact on the performance of the 2-stage compressor. The isentropic efficiency and thetotal pressure ratio of the compressor are increased near the design condition. The compressor total pressure ratiois decreased near choke and near stall. The maximum flow rate is reduced and the stall margin is decreased.展开更多
Curved blade and end-bend blade are considered as effective passive control methods for improving the aerodynamic performance of a compressor cascade,and their applicability also needs to be further studied.A highly-l...Curved blade and end-bend blade are considered as effective passive control methods for improving the aerodynamic performance of a compressor cascade,and their applicability also needs to be further studied.A highly-loaded compressor linear cascade in the design condition was taken as the research objective in this paper.Numerical simulation was used to study the positive and negative effects of these methods on the flow loss of the cascade by redistributing the vortex structures.Results show that:the curved blade could reduce the flow loss to 2.55%,while the end-bend blade and the end-bend+curved blade increase it to 10.58%and 2.19%,respectively.The positive effect of the curved blade weakens the strength and scale of Concentrated Shedding Vortex(CSV),which accounts for 59.2%of the total flow loss.The negative effect of the end-bend blade exacerbates the low-energy fluid clusters from the end wall and wake into CSV.Finally,the end-bend+curved blade can take their own strengths,but it enhances the twisting motion of Passage Vortex(PV)and CSV,which makes it fail to reduce the flow loss.Therefore,the positive and negative effects of these methods on the flow loss of a compressor cascade are much clearer.In addition,we also predict the potential danger of the end-bend blade in the negative incidence conditions and provides some suggestion for future study.展开更多
基金supported by National Natural Science Foundation of China (51006005,50736007)"Fan-Zhou" Youth Foundation(20100401)
文摘This study is aimed at using blade 3-D optimization to control corner flows in the high through-flow fan/booster of a high bypass ratio commercial turbofan engine. Two kinds of blade 3-D optimization, end-bending and bow, are focused on. On account of the respective operation mode and environment, the approach to 3-D aerodynamic modeling of rotor blades is different from stator vanes. Based on the understanding of the mechanism of the corner flow and the consideration of intensity problem for rotors, this paper uses a variety of blade 3-D optimization approaches, such as loading distribution optimization, perturbation of departure angles and stacking-axis manipulation, which are suitable for rotors and stators respectively. The obtained 3-D blades and vanes can improve the corner flow features by end-bending and bow effects. The results of this study show that flows in corners of the fan/booster, such as the fan hub region, the tip and hub of the vanes of the booster, are very complex and dominated by 3-D effects. The secondary flows there are found to have a strong detrimental effect on the compressor performance. The effects of both end-bending and bow can improve the flow separation in corners, but the specific ways they work and application scope are somewhat different. Redesigning the blades via blade 3-D optimization to control the corner flow has effectively reduced the loss generation and improved the stall margin by a large amount.
基金support of the National Basic Research Program of China (No.2007CB210104)
文摘Leading edge recambering is applied to the cantilevered stator vanes in a 2-stage compressor in this paper. Differentcurving effects are produced when the end-bend stator vanes are stacked in different ways. Stacking on theleading edge induces a positive curving effect near the casing.When it is stacked on the centre of gravity, a negativecurving effect takes place. The numerical investigation shows that the flow field is redistributed when theend-bend stators with leading edge stacking are applied. The variations in the stage matching for the mainstreamand near the hub have an impact on the performance of the 2-stage compressor. The isentropic efficiency and thetotal pressure ratio of the compressor are increased near the design condition. The compressor total pressure ratiois decreased near choke and near stall. The maximum flow rate is reduced and the stall margin is decreased.
基金co-supported by the China Postdoctoral Science Foundation(Grant No.2017M621268)the National Natural Science Foundation of China(Grant Nos.51436002 and 51506020)
文摘Curved blade and end-bend blade are considered as effective passive control methods for improving the aerodynamic performance of a compressor cascade,and their applicability also needs to be further studied.A highly-loaded compressor linear cascade in the design condition was taken as the research objective in this paper.Numerical simulation was used to study the positive and negative effects of these methods on the flow loss of the cascade by redistributing the vortex structures.Results show that:the curved blade could reduce the flow loss to 2.55%,while the end-bend blade and the end-bend+curved blade increase it to 10.58%and 2.19%,respectively.The positive effect of the curved blade weakens the strength and scale of Concentrated Shedding Vortex(CSV),which accounts for 59.2%of the total flow loss.The negative effect of the end-bend blade exacerbates the low-energy fluid clusters from the end wall and wake into CSV.Finally,the end-bend+curved blade can take their own strengths,but it enhances the twisting motion of Passage Vortex(PV)and CSV,which makes it fail to reduce the flow loss.Therefore,the positive and negative effects of these methods on the flow loss of a compressor cascade are much clearer.In addition,we also predict the potential danger of the end-bend blade in the negative incidence conditions and provides some suggestion for future study.
