Electrochemical machining (ECM) is an effective and economical manufacturing method for machining hard-to-cut metal materials that are often used in the aerospace field. Cathode design is very complicated in ECM and i...Electrochemical machining (ECM) is an effective and economical manufacturing method for machining hard-to-cut metal materials that are often used in the aerospace field. Cathode design is very complicated in ECM and is a core problem influencing machining accuracy, especially for complex profiles such as compressor blades in aero engines. A new cathode design method based on iterative correction of predicted profile errors in blade ECM is proposed in this paper. A mathematical model is first built according to the ECM shaping law, and a simulation is then carried out using ANSYS software. A dynamic forming process is obtained and machining gap distributions at different stages are analyzed. Additionally, the simulation deviation between the prediction profile and model is improved by the new method through correcting the initial cathode profile. Furthermore, validation experiments are conducted using cathodes designed before and after the simulation correction. Machining accuracy for the optimal cathode is improved markedly compared with that for the initial cathode. The experimental results illustrate the suitability of the new method and that it can also be applied to other complex engine components such as diffusers. (C) 2016 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics.展开更多
This paper discusses the modeling design and accuracy analysis of a single stage steam centrifugal compressor for China′S first seawater desalinization plant, and gives a brief presentation on the closed loop vapou...This paper discusses the modeling design and accuracy analysis of a single stage steam centrifugal compressor for China′S first seawater desalinization plant, and gives a brief presentation on the closed loop vapour test platform designed and constructed for qualification of the compress or for performance and operational reliability, and results of tests run with the compressor. Both tests and actual operation show the modeling design is successful, and the compressor achieved and exceeded what was expected in performance. The seawater desalinization plant has run with excellent performance and reliability for several years for the national seawater desalinization demonstration program. This proves it is practical and practicable to develop and design China′s steam centrifugal compressors in series from air centrifugal compressors by maintaining equal specific volume ratio at both inlet and outlet of the compressor.展开更多
In order to shorten the design period, the paper describes a new optimization strategy for computationally expensive design optimization of turbomachinery, combined with design of experiment (DOE), response surface mo...In order to shorten the design period, the paper describes a new optimization strategy for computationally expensive design optimization of turbomachinery, combined with design of experiment (DOE), response surface models (RSM), genetic algorithm (GA) and a 3-D Navier-Stokes solver(Numeca Fine). Data points for response evaluations were selected by improved distributed hypercube sampling (IHS) and the 3-D Navier-Stokes analysis was carried out at these sample points. The quadratic response surface model was used to approximate the relationships between the design variables and flow parameters. To maximize the adiabatic efficiency, the genetic algorithm was applied to the response surface model to perform global optimization to achieve the optimum design of NASA Stage 35. An optimum leading edge line was found, which produced a new 3-D rotor blade combined with sweep and lean, and a new stator one with skew. It is concluded that the proposed strategy can provide a reliable method for design optimization of turbomachinery blades at reasonable computing cost.展开更多
Cylinder valves are the most important parts of a reciprocating compressor; their working condition affects the safety and operation of the reciprocating compressor directly. In initial design, it is dedicated to simu...Cylinder valves are the most important parts of a reciprocating compressor; their working condition affects the safety and operation of the reciprocating compressor directly. In initial design, it is dedicated to simulate the behaviour of a reciprocating compressor and peorformance of cylinder valves. For hydrogen application, it is considering carefully the real operating conditions both from the dynamic point of view and taking care of the effective condi- tions of the gas purity. The dynamic aspects of the design are related to the mechanical behaviour and to the conse- quent fatigue. The mathematical models are able to determine the ring displacement and the flow and pressure drop of the gas. Instruments are available for on-line monitoring of the reciprocating compressor. The various parts have to be repaired in time in case they have abrupt problems during the operating period. By detail design and maintenance, saving the quantities of spare parts, the reciprocating compressor of the plant can be running smoothly. Actually, the cylinder valves can be used nearly three years.展开更多
The structural design of the IND100 axial compressor requires a multistage interrelationship between the thermodynamic, aerodynamic, mechanical design and structural integrity analysis of the component. These design c...The structural design of the IND100 axial compressor requires a multistage interrelationship between the thermodynamic, aerodynamic, mechanical design and structural integrity analysis of the component. These design criteria, sometimes act in opposition, hence engineering balance is employed within the specified design performance limits. This paper presents the structural and conceptual design of a sixteen stage single shaft high pressure compressor of IND100 with an overall pressure ratio of 12 and mass flow of 310 kg/s at ISOSLS conditions. Furthermore, in order to evaluate the conceptual design analysis, basic parameters like compressor sizing, load and blade mass, disc stress analysis, bearings and material selections, conceptual disc design and rotor dynamics are considered using existing tools and analytical technique. These techniques employed the basic thermodynamic and aerodynamic theory of axial flow compressors to determine the temperature and pressure for all stages, geometrical parameters, velocity triangle, and weight and stress calculations of the compressor disc using Sagerser Empirical Weight Estimation. The result analysis shows a constant hub diameter annulus configuration with compressor overall axial length of 3.75 m, tip blade speed of 301 m/s, maximum blade centrifugal force stress of 170 MPa, with major emphasis on industrial application for the structural component design selections.展开更多
Centrifugal compressors with parallel-wall and contracting wall vaneless diffuser are designed by using centrifugal compressor computer-aided integrated design system. The internal flow fields of the compressor are ca...Centrifugal compressors with parallel-wall and contracting wall vaneless diffuser are designed by using centrifugal compressor computer-aided integrated design system. The internal flow fields of the compressor are calculated by solving three-dimensional Navier-Stokes equation. Four aspects are investigated and calculation results show that the total efficiencies and total pressure ratios of the compressor with contracting wall vandess diffuser is higher than that of the compressor with parallel-wall. The jet and wake don＇t mix rapidly inside vandess diffuser. The outlet blade lean angle doesn＇t affect the compressor performance. The greater the mass flow rate through impeller, the more uneven the velocity distribution at impeller outlet is.展开更多
A series of numerical simulations were conducted in both a 1.5stage axial compressor model and a simplified planar cascade model.The cases with different blade sweep schemes in the cascade model were simulated with fr...A series of numerical simulations were conducted in both a 1.5stage axial compressor model and a simplified planar cascade model.The cases with different blade sweep schemes in the cascade model were simulated with free-slip endwalls to minimize the influence of endwall 3-D(three-dimensional)flows.The results obtained in the cascade model were discussed at first for getting a clear insight into the effects of blade sweep without other influences.And then the simulation results of the 1.5stage compressor model were discussed accordingly.The discussions focused on the influences of different meridional flowpath designs,i.e.constant mid radius(CMR)design,constant outer radius(COR)design and constant inner radius(CIR)design,on the performance of the swept blade.The results showed that the most critical effect produced by blade sweep was attributed to the redistribution of local mass-flow-rate in blade spanwise direction.The change of meridional flowpath did not change the mass-flow-rate redistribution behaviors.However,the trends for local mass-flow-rate redistribution in compressor stage model showed some discrepancies compared with the results shown in the planar cascade model.展开更多
Performance prediction in preliminary design stages of several turbomachinery components is a critical task in order to bring the design processes of these devices to a successful conclusion. In this paper, a review a...Performance prediction in preliminary design stages of several turbomachinery components is a critical task in order to bring the design processes of these devices to a successful conclusion. In this paper, a review and analysis of the major loss mechanisms and loss models, used to determine the efficiency of a single stage centrifugal compressor, and a subsequent examination to determine an appropriate loss correlation set for estimating the isentropic efficiency in preliminary design stages of centrifugal compressors, were developed. Several semi-empirical correlations,commonly used to predict the efficiency of centrifugal compressors, were implemented in FORTRAN code and then were compared with experimental results in order to establish a loss correlation set to determine, with good approximation, the isentropic efficiency of single stage compressor.The aim of this study is to provide a suitable loss correlation set for determining the isentropic efficiency of a single stage centrifugal compressor, because, with a large amount of loss mechanisms and correlations available in the literature, it is difficult to ascertain how many and which correlations to employ for the correct prediction of the efficiency in the preliminary stage design of a centrifugal compressor. As a result of this study, a set of correlations composed by nine loss mechanisms for single stage centrifugal compressors, conformed by a rotor and a diffuser, are specified.展开更多
To enable flexible and rapid aerodynamic performance evaluation in turbomachinery design,this paper proposes a panoramic performance prediction framework.Unlike most previous prediction models that directly predict th...To enable flexible and rapid aerodynamic performance evaluation in turbomachinery design,this paper proposes a panoramic performance prediction framework.Unlike most previous prediction models that directly predict the objective functions of interest,the approach first predicts the basic parameters of the Navier–Stokes equations,such as temperature,pressure,and density.Utilizing these basic physical quantities,it subsequently predicts key performance parameters of the turbine stage meridian plane.By adopting this methodology,the proposed panoramic performance prediction framework functions similarly to a CFD simulator,capable of predicting various objective of interest to the designers.To enhance prediction accuracy,a Transformer-enhanced Neural Operator(TNO)is introduced within this framework.Using the Rotor 37 blades as a reference,the proposed TNO is trained to predict the performance of a transonic compressor blade in the meridian plane.The TNO can accurately predict total quantities such as isentropic efficiency,mass flow,and distributions of total pressure ratio.Remarkably,the prediction error of TNO is observed to be smaller than that of state-of-the-art deep learning operators such as the Fourier Neural Operator(FNO)network and Deep Operator Network(DeepONet).Furthermore,the TNO is applied to downstream tasks,including sensitivity analysis and optimization of various objective functions.The results confirm that the TNO can operate almost like a CFD simulator,while reducing the computational cost of downstream tasks by four orders of magnitude.The effectiveness and reliability of the proposed TNO for solving different kinds of downstream tasks have been well demonstrated.展开更多
基金co-supported by the National Natural Science Foundation of China (No. 51205199)the Natural Science Foundation of Jiangsu Province (No. BK2012387)the Fundamental Research Funds for the Central Universities (No. NE 2015105)
文摘Electrochemical machining (ECM) is an effective and economical manufacturing method for machining hard-to-cut metal materials that are often used in the aerospace field. Cathode design is very complicated in ECM and is a core problem influencing machining accuracy, especially for complex profiles such as compressor blades in aero engines. A new cathode design method based on iterative correction of predicted profile errors in blade ECM is proposed in this paper. A mathematical model is first built according to the ECM shaping law, and a simulation is then carried out using ANSYS software. A dynamic forming process is obtained and machining gap distributions at different stages are analyzed. Additionally, the simulation deviation between the prediction profile and model is improved by the new method through correcting the initial cathode profile. Furthermore, validation experiments are conducted using cathodes designed before and after the simulation correction. Machining accuracy for the optimal cathode is improved markedly compared with that for the initial cathode. The experimental results illustrate the suitability of the new method and that it can also be applied to other complex engine components such as diffusers. (C) 2016 Production and hosting by Elsevier Ltd. on behalf of Chinese Society of Aeronautics and Astronautics.
文摘This paper discusses the modeling design and accuracy analysis of a single stage steam centrifugal compressor for China′S first seawater desalinization plant, and gives a brief presentation on the closed loop vapour test platform designed and constructed for qualification of the compress or for performance and operational reliability, and results of tests run with the compressor. Both tests and actual operation show the modeling design is successful, and the compressor achieved and exceeded what was expected in performance. The seawater desalinization plant has run with excellent performance and reliability for several years for the national seawater desalinization demonstration program. This proves it is practical and practicable to develop and design China′s steam centrifugal compressors in series from air centrifugal compressors by maintaining equal specific volume ratio at both inlet and outlet of the compressor.
文摘In order to shorten the design period, the paper describes a new optimization strategy for computationally expensive design optimization of turbomachinery, combined with design of experiment (DOE), response surface models (RSM), genetic algorithm (GA) and a 3-D Navier-Stokes solver(Numeca Fine). Data points for response evaluations were selected by improved distributed hypercube sampling (IHS) and the 3-D Navier-Stokes analysis was carried out at these sample points. The quadratic response surface model was used to approximate the relationships between the design variables and flow parameters. To maximize the adiabatic efficiency, the genetic algorithm was applied to the response surface model to perform global optimization to achieve the optimum design of NASA Stage 35. An optimum leading edge line was found, which produced a new 3-D rotor blade combined with sweep and lean, and a new stator one with skew. It is concluded that the proposed strategy can provide a reliable method for design optimization of turbomachinery blades at reasonable computing cost.
文摘Cylinder valves are the most important parts of a reciprocating compressor; their working condition affects the safety and operation of the reciprocating compressor directly. In initial design, it is dedicated to simulate the behaviour of a reciprocating compressor and peorformance of cylinder valves. For hydrogen application, it is considering carefully the real operating conditions both from the dynamic point of view and taking care of the effective condi- tions of the gas purity. The dynamic aspects of the design are related to the mechanical behaviour and to the conse- quent fatigue. The mathematical models are able to determine the ring displacement and the flow and pressure drop of the gas. Instruments are available for on-line monitoring of the reciprocating compressor. The various parts have to be repaired in time in case they have abrupt problems during the operating period. By detail design and maintenance, saving the quantities of spare parts, the reciprocating compressor of the plant can be running smoothly. Actually, the cylinder valves can be used nearly three years.
文摘The structural design of the IND100 axial compressor requires a multistage interrelationship between the thermodynamic, aerodynamic, mechanical design and structural integrity analysis of the component. These design criteria, sometimes act in opposition, hence engineering balance is employed within the specified design performance limits. This paper presents the structural and conceptual design of a sixteen stage single shaft high pressure compressor of IND100 with an overall pressure ratio of 12 and mass flow of 310 kg/s at ISOSLS conditions. Furthermore, in order to evaluate the conceptual design analysis, basic parameters like compressor sizing, load and blade mass, disc stress analysis, bearings and material selections, conceptual disc design and rotor dynamics are considered using existing tools and analytical technique. These techniques employed the basic thermodynamic and aerodynamic theory of axial flow compressors to determine the temperature and pressure for all stages, geometrical parameters, velocity triangle, and weight and stress calculations of the compressor disc using Sagerser Empirical Weight Estimation. The result analysis shows a constant hub diameter annulus configuration with compressor overall axial length of 3.75 m, tip blade speed of 301 m/s, maximum blade centrifugal force stress of 170 MPa, with major emphasis on industrial application for the structural component design selections.
文摘Centrifugal compressors with parallel-wall and contracting wall vaneless diffuser are designed by using centrifugal compressor computer-aided integrated design system. The internal flow fields of the compressor are calculated by solving three-dimensional Navier-Stokes equation. Four aspects are investigated and calculation results show that the total efficiencies and total pressure ratios of the compressor with contracting wall vandess diffuser is higher than that of the compressor with parallel-wall. The jet and wake don＇t mix rapidly inside vandess diffuser. The outlet blade lean angle doesn＇t affect the compressor performance. The greater the mass flow rate through impeller, the more uneven the velocity distribution at impeller outlet is.
基金National Science Foundation of China(51006007,51136003,50976009)
文摘A series of numerical simulations were conducted in both a 1.5stage axial compressor model and a simplified planar cascade model.The cases with different blade sweep schemes in the cascade model were simulated with free-slip endwalls to minimize the influence of endwall 3-D(three-dimensional)flows.The results obtained in the cascade model were discussed at first for getting a clear insight into the effects of blade sweep without other influences.And then the simulation results of the 1.5stage compressor model were discussed accordingly.The discussions focused on the influences of different meridional flowpath designs,i.e.constant mid radius(CMR)design,constant outer radius(COR)design and constant inner radius(CIR)design,on the performance of the swept blade.The results showed that the most critical effect produced by blade sweep was attributed to the redistribution of local mass-flow-rate in blade spanwise direction.The change of meridional flowpath did not change the mass-flow-rate redistribution behaviors.However,the trends for local mass-flow-rate redistribution in compressor stage model showed some discrepancies compared with the results shown in the planar cascade model.
文摘Performance prediction in preliminary design stages of several turbomachinery components is a critical task in order to bring the design processes of these devices to a successful conclusion. In this paper, a review and analysis of the major loss mechanisms and loss models, used to determine the efficiency of a single stage centrifugal compressor, and a subsequent examination to determine an appropriate loss correlation set for estimating the isentropic efficiency in preliminary design stages of centrifugal compressors, were developed. Several semi-empirical correlations,commonly used to predict the efficiency of centrifugal compressors, were implemented in FORTRAN code and then were compared with experimental results in order to establish a loss correlation set to determine, with good approximation, the isentropic efficiency of single stage compressor.The aim of this study is to provide a suitable loss correlation set for determining the isentropic efficiency of a single stage centrifugal compressor, because, with a large amount of loss mechanisms and correlations available in the literature, it is difficult to ascertain how many and which correlations to employ for the correct prediction of the efficiency in the preliminary stage design of a centrifugal compressor. As a result of this study, a set of correlations composed by nine loss mechanisms for single stage centrifugal compressors, conformed by a rotor and a diffuser, are specified.
文摘针对高压氢能加注场景下90 MPa隔膜式氢气压缩机面临的设备振动、氢腐蚀、膜片疲劳及密封失效等核心难题,通过气-固-液多物理场耦合仿真、抗氢脆结构创新、油气协同调控技术及复合膜腔型线设计,构建“设计-材料-工艺-安全-产业化”一体化解决方案。研究优化两列对称平衡型主机结构,采用配气盘内嵌式组合缸盖、一体化硬密封膜片与抛物线-圆弧复合膜腔型线,研发高低压一体化油泵驱动机构、波形弹簧气阀及高可靠性连杆衬套。性能测试结果表明,整机振动≤8 mm s、膜片寿命提升至8000 h以上、连杆衬套寿命突破50000 h、排气压力稳定达90 MPa(排气量500 m 3 h),国产化率达95%。该研究为高压氢能装备国产化与规模化应用提供关键技术支撑,设备性能达国际先进水平。
基金supported by the National Science and Technology Major Project,China(No.2019-II-0008–0028)。
文摘To enable flexible and rapid aerodynamic performance evaluation in turbomachinery design,this paper proposes a panoramic performance prediction framework.Unlike most previous prediction models that directly predict the objective functions of interest,the approach first predicts the basic parameters of the Navier–Stokes equations,such as temperature,pressure,and density.Utilizing these basic physical quantities,it subsequently predicts key performance parameters of the turbine stage meridian plane.By adopting this methodology,the proposed panoramic performance prediction framework functions similarly to a CFD simulator,capable of predicting various objective of interest to the designers.To enhance prediction accuracy,a Transformer-enhanced Neural Operator(TNO)is introduced within this framework.Using the Rotor 37 blades as a reference,the proposed TNO is trained to predict the performance of a transonic compressor blade in the meridian plane.The TNO can accurately predict total quantities such as isentropic efficiency,mass flow,and distributions of total pressure ratio.Remarkably,the prediction error of TNO is observed to be smaller than that of state-of-the-art deep learning operators such as the Fourier Neural Operator(FNO)network and Deep Operator Network(DeepONet).Furthermore,the TNO is applied to downstream tasks,including sensitivity analysis and optimization of various objective functions.The results confirm that the TNO can operate almost like a CFD simulator,while reducing the computational cost of downstream tasks by four orders of magnitude.The effectiveness and reliability of the proposed TNO for solving different kinds of downstream tasks have been well demonstrated.
