This paper presents the design and verification of the dual-mode core driven fan stage(CDFS)and high-load compressor with a large flow regulation range.In view of the characteristics of large flow regulation range of ...This paper presents the design and verification of the dual-mode core driven fan stage(CDFS)and high-load compressor with a large flow regulation range.In view of the characteristics of large flow regulation range of the two modes and high average stage load coefficient,this paper investigates the design technology of the dual-mode high-efficiency compressor with a large flow regulation range and high-load compressor with an average stage load coefficient of 0.504.Building upon this research,the design of the dual-mode CDFS and four-stage compressor is completed,and three-dimensional numerical simulation of the two modes is carried out.Finally,performance experiment is conducted to verify the result of three-dimensional numerical simulation.The experiment results show that the compressor performance is improved for the whole working conditions by using the new design method,which realizes the complete fusion design of the CDFS and high-pressure compressor(HPC).The matching mechanism of stage characteristics of single and double bypass modes and the variation rule of different adjustment angles on performance are studied comprehensively.Furthermore,it effectively reduces the length and weight of compressor,and breaks through the key technologies such as high-load compressor with the average load factor of 0.504.These findings provide valuable data and a methodological foundation for the development of the next generation aeroengine.展开更多
This work involves an experimental study on the performance of automobile air-conditioning systems by adding Al_(2)O_(3)nanoparticles to oil compressors to investigate their impacts on the enhancement of the speed coo...This work involves an experimental study on the performance of automobile air-conditioning systems by adding Al_(2)O_(3)nanoparticles to oil compressors to investigate their impacts on the enhancement of the speed cooling of refrigeration systems and to compare it with the system operated using only oil.The Al_(2)O_(3)nanoparticles have been added to the oil compressor for different ranges ofmass concentration(Ф=0.1%,Ф=0.15%andФ=0.2%).The stability of Al_(2)O_(3)nanoparticles has been tested by direct observation for different time periods.The results indicated that the air conditioning systemthat operated by using Al_(2)O_(3)-oil was better than the system that operated with pure oil.ForФ=0.2%,the results indicated that the cooling speed and the efficiency of the system operated with Al_(2)O_(3)-oil are increased by 13%and 18%,respectively,as compared to the pure oil system.This study shows that the thermos-physical properties of refrigerant oil are enhanced by 15%whenФis increased.展开更多
Double-layer structure of seal coating which consisted of a Ni5Al bond coating and a Ni25 graphite top coating were prepared on steel substrate of gas turbine compressor cylinder block.Bond coating was prepared by atm...Double-layer structure of seal coating which consisted of a Ni5Al bond coating and a Ni25 graphite top coating were prepared on steel substrate of gas turbine compressor cylinder block.Bond coating was prepared by atmospheric plasma spraying and top coating was prepared by flame spraying.The microstructure,mechanical properties and abradability of the coating were characterized by scanning elec-tron microscope(SEM),hardness tester,universal testing machine,thermal shock testing machine and abradability testing machine.The res-ults show that the overall spraying structure of the seal coating is uniform,the nickel metal phase is the skeleton supporting the entire coat-ing,and the coating is well bonded without separation.The seal coating has a bonding strength of not less than 7.7 MPa,excellent thermal stability,and thermal shock resistance cycle numbers at 500℃more than 50;the scratch length,deepest invasion depth and wear amount of the coating increase with rise of test temperature,with almost no coating adhesion,indicating that the seal coating has excellent abradability.展开更多
Due to increasingly stricter emissions on particulate matter(PM)emissions,diesel particulate filter(DPF)regeneration has become the most widely used and effective technology to reduce PM emissions.However,using incyli...Due to increasingly stricter emissions on particulate matter(PM)emissions,diesel particulate filter(DPF)regeneration has become the most widely used and effective technology to reduce PM emissions.However,using incylinder post-injection-based active DPF regeneration can increase engine oil dilution,thus affecting engine lubrication.Using a 4-cylinder turbocharged direct-injection diesel engine,this study analyzed the effect of lubricating oil on the formation and properties of turbocharger compressor soot deposits associated with engine oil dilution.Three diesel engine lubricating oils(CJ-4,CK-4,and CJ-4*)were selected,with each subjected to 200 hours of engine bench testing at 8%oil dilution.The composition of CJ-4*was the same as that of CJ-4 but with reduced amount of additives.Soot deposits were collected and analyzed.A merit calculation method was established to rate turbocharger deposits.Transmission electron microscopy,Raman spectroscopy,Fourier transform infrared spectroscopy,and thermogravimetric analysis(TGA)were used to characterize the morphology and composition of soot samples.The results showed that turbocharger deposits from CJ-4 and CK-4 were less than that from CJ-4*.The deposits from CJ-4*showed a more disordered morphology,whereas those from CJ-4 and CK-4 exhibited a higher degree of order.TGA results showed that the soluble organic fraction content in the deposit derived from CJ-4*was much higher than that obtained from CJ-4 and CK-4.展开更多
The accurate parameters measurement of the flow field between the stages for axial compressors is a significant demand.This paper proposes an axial compressor inter-stage flow field high-precision test system,which ma...The accurate parameters measurement of the flow field between the stages for axial compressors is a significant demand.This paper proposes an axial compressor inter-stage flow field high-precision test system,which mainly consists of a probe motion scanning mechanism,fully automated test control software,and data processing methods.Iterative correction is applied to the original readings obtained from the scanning tests to enhance testing accuracy.Using this test system,detailed tests are conducted on a 1.5-stage subsonic axial compressor under different operating conditions.The test results effectively captured the impact of surface roughness and tip clearance variations on compressor performance.The distribution characteristics of parameters measured in inter-stage sections can characterize the effects of blade wake area and changes in aerodynamic performance at different blade heights.The developed test system can be extended to multi-stage compressors.展开更多
The design objectives of modern aircraft engines include high load capacity,efficiency,and stability.With increasing loads,the phenomenon of corner separation in compressors intensifies,affecting engine performance an...The design objectives of modern aircraft engines include high load capacity,efficiency,and stability.With increasing loads,the phenomenon of corner separation in compressors intensifies,affecting engine performance and stability.Therefore,the adoption of appropriate flow control technology holds significant academic and engineering significance.This study employs the Reynolds-averaged Navier-Stokes(RANS)method to investigate the effects and mechanisms of active/passive Co-flow Jet(CFJ)control,implemented by introducing full-height and partial height jet slots between the suction surface and end wall of a compressor cascade.The results indicate that passive CFJ control significantly reduces the impact of corner separation at small incidence,with partial-height control further enhancing the effectiveness.The introduction of active CFJ enables separation control at large incidence,improving blade performance under different operating conditions.Active control achieves this by reducing the scale of corner separation vortices,effectively reducing the size of the separation region and enhancing blade performance.展开更多
There is introduced a new low-reaction, highly-loaded axial compressor design concept which is coupled with boundary layer suction method. The characteristic features of the concept are made clear through its comparis...There is introduced a new low-reaction, highly-loaded axial compressor design concept which is coupled with boundary layer suction method. The characteristic features of the concept are made clear through its comparison with the MIT boundary layer suction compressor. Also are pointed out the potential applications of this concept as well as its key technological problems. Based on this concept, a single-stage, low-reaction and low-speed axial compressor is constructed in association with analysis and computation of boundary layer suction on vanes with the aid of a three-dimensional numerical approach. The results attest to the effectiveness of this way to control separation in blade cascades by the boundary layer suction and the feasibility of this proposed design concept.展开更多
文摘This paper presents the design and verification of the dual-mode core driven fan stage(CDFS)and high-load compressor with a large flow regulation range.In view of the characteristics of large flow regulation range of the two modes and high average stage load coefficient,this paper investigates the design technology of the dual-mode high-efficiency compressor with a large flow regulation range and high-load compressor with an average stage load coefficient of 0.504.Building upon this research,the design of the dual-mode CDFS and four-stage compressor is completed,and three-dimensional numerical simulation of the two modes is carried out.Finally,performance experiment is conducted to verify the result of three-dimensional numerical simulation.The experiment results show that the compressor performance is improved for the whole working conditions by using the new design method,which realizes the complete fusion design of the CDFS and high-pressure compressor(HPC).The matching mechanism of stage characteristics of single and double bypass modes and the variation rule of different adjustment angles on performance are studied comprehensively.Furthermore,it effectively reduces the length and weight of compressor,and breaks through the key technologies such as high-load compressor with the average load factor of 0.504.These findings provide valuable data and a methodological foundation for the development of the next generation aeroengine.
文摘This work involves an experimental study on the performance of automobile air-conditioning systems by adding Al_(2)O_(3)nanoparticles to oil compressors to investigate their impacts on the enhancement of the speed cooling of refrigeration systems and to compare it with the system operated using only oil.The Al_(2)O_(3)nanoparticles have been added to the oil compressor for different ranges ofmass concentration(Ф=0.1%,Ф=0.15%andФ=0.2%).The stability of Al_(2)O_(3)nanoparticles has been tested by direct observation for different time periods.The results indicated that the air conditioning systemthat operated by using Al_(2)O_(3)-oil was better than the system that operated with pure oil.ForФ=0.2%,the results indicated that the cooling speed and the efficiency of the system operated with Al_(2)O_(3)-oil are increased by 13%and 18%,respectively,as compared to the pure oil system.This study shows that the thermos-physical properties of refrigerant oil are enhanced by 15%whenФis increased.
基金supported by Zhejiang Provincial Science and Technology Plan Project(Grant No.2022C01118).
文摘Double-layer structure of seal coating which consisted of a Ni5Al bond coating and a Ni25 graphite top coating were prepared on steel substrate of gas turbine compressor cylinder block.Bond coating was prepared by atmospheric plasma spraying and top coating was prepared by flame spraying.The microstructure,mechanical properties and abradability of the coating were characterized by scanning elec-tron microscope(SEM),hardness tester,universal testing machine,thermal shock testing machine and abradability testing machine.The res-ults show that the overall spraying structure of the seal coating is uniform,the nickel metal phase is the skeleton supporting the entire coat-ing,and the coating is well bonded without separation.The seal coating has a bonding strength of not less than 7.7 MPa,excellent thermal stability,and thermal shock resistance cycle numbers at 500℃more than 50;the scratch length,deepest invasion depth and wear amount of the coating increase with rise of test temperature,with almost no coating adhesion,indicating that the seal coating has excellent abradability.
基金financially supported by SINOPEC(Grant No.124015)。
文摘Due to increasingly stricter emissions on particulate matter(PM)emissions,diesel particulate filter(DPF)regeneration has become the most widely used and effective technology to reduce PM emissions.However,using incylinder post-injection-based active DPF regeneration can increase engine oil dilution,thus affecting engine lubrication.Using a 4-cylinder turbocharged direct-injection diesel engine,this study analyzed the effect of lubricating oil on the formation and properties of turbocharger compressor soot deposits associated with engine oil dilution.Three diesel engine lubricating oils(CJ-4,CK-4,and CJ-4*)were selected,with each subjected to 200 hours of engine bench testing at 8%oil dilution.The composition of CJ-4*was the same as that of CJ-4 but with reduced amount of additives.Soot deposits were collected and analyzed.A merit calculation method was established to rate turbocharger deposits.Transmission electron microscopy,Raman spectroscopy,Fourier transform infrared spectroscopy,and thermogravimetric analysis(TGA)were used to characterize the morphology and composition of soot samples.The results showed that turbocharger deposits from CJ-4 and CK-4 were less than that from CJ-4*.The deposits from CJ-4*showed a more disordered morphology,whereas those from CJ-4 and CK-4 exhibited a higher degree of order.TGA results showed that the soluble organic fraction content in the deposit derived from CJ-4*was much higher than that obtained from CJ-4 and CK-4.
基金National Science and Technology Major Project of China No.2017-V-0012-0064。
文摘The accurate parameters measurement of the flow field between the stages for axial compressors is a significant demand.This paper proposes an axial compressor inter-stage flow field high-precision test system,which mainly consists of a probe motion scanning mechanism,fully automated test control software,and data processing methods.Iterative correction is applied to the original readings obtained from the scanning tests to enhance testing accuracy.Using this test system,detailed tests are conducted on a 1.5-stage subsonic axial compressor under different operating conditions.The test results effectively captured the impact of surface roughness and tip clearance variations on compressor performance.The distribution characteristics of parameters measured in inter-stage sections can characterize the effects of blade wake area and changes in aerodynamic performance at different blade heights.The developed test system can be extended to multi-stage compressors.
基金National Science&Technology Major Project(Grant No.2017-II-0004-0016)National Nature Science Foundation of China(Grant No.52176044)。
文摘The design objectives of modern aircraft engines include high load capacity,efficiency,and stability.With increasing loads,the phenomenon of corner separation in compressors intensifies,affecting engine performance and stability.Therefore,the adoption of appropriate flow control technology holds significant academic and engineering significance.This study employs the Reynolds-averaged Navier-Stokes(RANS)method to investigate the effects and mechanisms of active/passive Co-flow Jet(CFJ)control,implemented by introducing full-height and partial height jet slots between the suction surface and end wall of a compressor cascade.The results indicate that passive CFJ control significantly reduces the impact of corner separation at small incidence,with partial-height control further enhancing the effectiveness.The introduction of active CFJ enables separation control at large incidence,improving blade performance under different operating conditions.Active control achieves this by reducing the scale of corner separation vortices,effectively reducing the size of the separation region and enhancing blade performance.
基金National Defense Basic Research Program of China
文摘There is introduced a new low-reaction, highly-loaded axial compressor design concept which is coupled with boundary layer suction method. The characteristic features of the concept are made clear through its comparison with the MIT boundary layer suction compressor. Also are pointed out the potential applications of this concept as well as its key technological problems. Based on this concept, a single-stage, low-reaction and low-speed axial compressor is constructed in association with analysis and computation of boundary layer suction on vanes with the aid of a three-dimensional numerical approach. The results attest to the effectiveness of this way to control separation in blade cascades by the boundary layer suction and the feasibility of this proposed design concept.
