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Method for Evaluating the Reliability of Compressor Impeller of Turbocharger for Vehicle Application in Plateau Area

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Chinese Journal of Mechanical engineering 2016年第6期29卷 1218-1225页

作者： WANG Zheng WANG Zengquan WANG A-na ZHUANG Li WANG Jinwei key laboratory of diesel engine turbocharging technology China North Engine Research Institute Center of engine Test and Measurement China North Engine Research Institute

As turbocharging diesel engines for vehicle application are applied in plateau area, the environmental adaptability of engines has drawn more attention. For the environmental adaptability problem of turbocharging diesel engines for vehicle application, the present studies almost focus on the optimization of performance match between turbocharger and engine, and the reliability problem of turbocharger is almost ignored. The reliability problem of compressor impeller of turhocharger for vehicle application when diesel engines operate in plateau area is studied. Firstly, the rule that the rotational speed of turbocharger changes with the altitude height is presented, and the potential failure modes of compressor impeller are analyzed. Then, the failure behavior models of compressor impeller are built, and the reliability models of compressor impeller operating in plateau area are developed. Finally, the rule that the reliability of compressor impeller changes with the altitude height is studied, the measurements for improving the reliability of the compressor impellers of turbocharger operating in plateau area are given. The results indicate that when the operating speed of diesel engine is certain, the rotational speed of turbocharger increases with the increase of altitude height, and the failure risk of compressor impeller with the failure modes of hub fatigue and blade resonance increases. The reliability of compressor impeller decreases with the increase of altitude height, and it also decreases as the increase of number of the mission profile cycle of engine. The method proposed can not only be used to evaluating the reliability of compressor impeller when diesel engines operate in plateau area but also be applied to direct the structural optimization of compressor impeller.

关键词： turbocharger plateau area compressor impeller failure behavior reliability

Time-dependent Vibration Frequency Reliability Analysis of Blade Vibration of Compressor Wheel of Turbocharger for Vehicle Application

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Chinese Journal of Mechanical engineering 2014年第1期27卷 205-210页

作者： WANG Zheng WANG Zengquan ZHUANG Li WANG A-na Science and technology on diesel engine turbocharging laboratory China North Engine Research Institute Center of engine Test and Measurement China North Engine Research Institute

Blade vibration failure is one of the main failure modes of compressor wheel of turbocharger for vehicle application. The existing models for evaluating the reliability of blade vibration of compressor wheel are static, and can not reflect the relationship between the reliability of compressor wheel with blade vibration failure mode and the life parameter. For the blade vibration failure mode of compressor wheel of turbocharger, the reliability evaluation method is studied. Taking a compressor wheel of turbocharger for vehicle application as an example, the blade vibration characteristics and how they change with the operating parameters of turbocharger are analyzed. The failure criterion for blade vibration mode of compressor wheel is built with the Campbell diagram, and taking the effect of the dispersity of blade natural vibration frequency and randomness of turbocharger operating speed into account, time-dependent reliability models of compressor wheel with blade vibration failure mode are derived, which embody the parameters of blade natural vibration frequency, turbocharger operating speed, the blade number of compressor wheel, life index and minimum number of resonance, etc. Finally, the rule governing the reliability and failure rate of compressor wheel and the method for determining the reliable life of compressor with blade vibration is presented. A method is proposed to evaluate the reliability of compressor wheel with blade vibration failure mode time-dependently.

关键词： turbocharger compressor wheel blade vibration reliability failure rate reliable life

Investigation on Centrifugal Impeller in an Axial-radial Combined Compressor with Inlet Distortion

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Journal of Thermal Science 2011年第6期20卷 486-494页

作者： Du Li Ce Yang Ben Zhao Mi Zhou Mingxu Qi Jizhong Zhang School of Mechanical engineering Beijing Institute of Technology Beijing China Basic Subject Department Bohai Shipbuilding Vocational College Huludao China national key laboratory of diesel engine turbocharging technology Datong China

Assembling an axial rotor and a stator at centrifugal compressor upstream to build an axial-radial combined compressor could achieve high pressure ratio and efficiency by appropriate size *** upstream potential flow and wake effect appear at centrifugal impeller *** this paper,the axial-radial compressor is unsteadily simulated by three-dimensional Reynolds averaged Navier-Stokes equations with uniform and circumferential distorted total pressure inlet condition to investigate upstream effect on radial *** results show that spanwise nonuniform total pressure distribution is generated and radial and circumferential combined distortion is formed at centrifugal rotor *** upstream stator wake deflects to rotor rotation direction and decreases with blade span *** distortion causes different separated flow formations at different pitch *** tip leakage vortex is suppressed in centrifugal blade *** distorted inlet condition,flow direction of centrifugal impeller leading edge upstream varies evidently near hub and shroud but varies slightly at *** addition,compressor stage inlet distortion produces remarkable effect on blade loading of centrifugal blade both along chordwise and pitchwise.

关键词： axial-radial combined compressor centrifugal impeller wake inlet distortion

Effects of pulse flow and leading edge sweep on mixed flow turbines for engine exhaust heat recovery

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Science China(Technological Sciences) 2011年第2期54卷 295-301页

作者： ZHANG YangJun CHEN Li ZHUGE WeiLin ZHANG ShuYong State key laboratory of Automotive Safety and Energy Tsinghua University Beijing 100084 China national key laboratory of diesel engine turbocharging technology P.O.B. 22 Datong 037036 China

Recovery of heat energy from internal combustion engine exhaust will achieve significant road transportation CO2 reduction. turbocharging and turbogenerating are most commonly used technologies to recover engine exhaust heat *** exhaust pulse flow can significantly affect the turbine performance of turbocharging and turbogenerating systems,and it is necessary to consider the pulse flow effects in turbine design and performance *** investigation was carried out by numerical simulation on the mixed flow turbine pulse flow performance and flow *** showed that the variations of the turbine efficiency and flowfiled under pulsating flow conditions demonstrate significant unsteady *** effect of blade leading edge sweep on turbine pulse flow performance was *** is shown that increasing of the leading edge sweep angle can improve the turbine average instantaneous efficiency by about 2 percent under pulsating flow conditions.

关键词： waste heat recovery mixed flow turbine pusle flow

Numerical study on the separation and superposition of the influences from up-and downstream rotors

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Journal of Beijing Institute of technology 2014年第4期23卷 469-480页

作者：赵奔杨策胡良军马朝臣张继忠 School of Mechanical engineering Beijing Institute of Technology Science and technology on diesel engine turbocharging laboratory China North Engine Research Institute

A three-dimensional Navier-Stokes solver is used to investigate the separation and superposition of the influences from upstream and downstream rotors in an axial-radial combined compressor for unsteady design applications. The data from rotor/stator and stator/rotor configurations show that the unsteady flow response in axial stator passage is caused only by one rotor. The results from the rotor/stator/rotor configuration revealed the superimposed characteristic of influences from upstream and downstream the rotor. The impact of the superimposed characteristic was studied by analyzing the virtual relative flow angle at the stator exit. The results show that the axial velocity in the passage of axial stator can be influenced by wake from upstream axial rotor and potential field of downstream radial rotor. While they are coupled to have an effect on the unsteady flow in axial statot passage, the excitation or suppression phenomena appear and lead to different levels of deterministic fluctuation kinetic energy. Their locations are determined by the frequencies of the involved influences. In addition, the variability of superimposed characteristic （ excitation and suppression） at the stator exit modulates the inlet flow angle for downstream rotor.

关键词： axial-radial combined compressor separation superposition unsteady flow angle

Numerical Investigation of the Superimposed Effects on Stator Wake Oscillation in an Axial-radial Combined Compressor

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Journal of Thermal Science 2014年第1期23卷 22-35页

作者： ZHAO Ben YANG Ce HU Liangjun ZHOU Mi ZHANG Jizhong School of Mechanical engineering Beijing Institute of Technology Basic Subject Department Bohai Shipbuilding Vocational College Science and technology on diesel engine turbocharging laboratory China North Engine Research Institute

The superimposed influences of the blade rows in a multistage compressor are important because different matches of upstream and downstream blades can result in significant differences in the stator wake oscillation. Numerical investigation of the axial stator wake oscillation, which is affected upstream by the axial rotor and downstream by the radial rotor, was performed in an axial-radial combined compressor. Many configurations with different blade numbers and locations, which influence axial stator wake oscillation were investigated. When rotors have equal blade numbers, the axial stator wake oscillates periodically versus time within time T(moving blade passing 1/3 revolution). In contrast, stator wake oscillates irregularly within T when rotors have different blade numbers. A model-split subtraction method is presented in order to separate the influences of the individual blade rows on the wake oscillation of the axial stator. Analysis from the rotor-stator configuration showed that the unsteady flow angle fluctuation response is caused by the upstream rotor. For the rotor-stator-rotor configuration, the unsteady flow angle fluctuations are influenced by upand downstream blade rows. With the model-split subtraction method, the upand downstream influences on the flow angle fluctuation could be clearly separated and quantified. Low amplitudes could be observed when the influences from upand downstream moving rows were superimposed with the "positive peaknegative peak" type wave. Clocking investigations were carried out to change the relative superimposed phase of influences from the surrounding blade rows in order to modulate the amplitudes of the axial stator wake oscillation. However, the amplitudes did not reach the maximum when they were superimposed with "positive peak-positive peak" type wave due to the impact of the interaction between the two moving blade rows.

关键词： axial-radial combined compressor wake oscillation superimposed effect absolute flow angle clocking

Numerical Analysis of Nozzle Clearance's Effect on Turbine Performance

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Chinese Journal of Mechanical engineering 2011年第4期24卷 618-625页

作者： HU Liangjun YANG Ce SUN Harold ZHANG Jizhong LAI Mingchia School of Mechanical engineering Beijing Institute of Technology Beijing 100081 China FordMotor Company Michigan 48124 USA national key laboratory of diesel engine turbocharging technology Datong 037036 China Wayne State University Michigan 48122 USA

Variable nozzle turbine （VNT） has become a popular variable geometry turbine （VGT） technology for the diesel engine application. Nozzle clearance, which can＇t be avoided on the hub and shroud side of the VNT turbine due to the pivoting stators, can lead to turbine performance deterioration. However, its mechanism is still not clear. In this paper, numerical investigation, which is validated by experiment, is carried out to study the mechanism of the nozzle clearance＇s effect on the turbine performance. Firstly, performance of the mixed flow turbine with fixed nozzle clearances tested on flow bench. Performance of the tested turbine with the same nozzle clearance is numerically simulated. The numerical result agrees well with the test data, which proves correct of the numerical method. Then the turbine performance with different nozzle clearances is numerically analyzed. The research showed that with nozzle clearance, flow loss in the nozzle increases at first and it reaches the maximum value when the clearance ratio is 5%. Flow at the exit of the nozzle becomes less uniform with nozzle clearance. The negative incidence angle of the rotor also increases with nozzle clearance and leads to more incidence angle loss in the rotor. The low energy fluid formed in the nozzle due to the nozzle clearance migrates from hub to shroud side in the rotor, which is another main reason for the rotor＇s performance degradation. The present research exposed the mechanism of the dramatically decrease of the turbine performance with nozzle clearance：（a） The loss associated with the nozzle leakage increases with the nozzle clearance; （b） The flow loss grows up quickly in the rotor due to the incidence angle loss and migration of the low energy fluid from hub to shroud side.

关键词： nozzle clearance variable nozzle turbine (VNT) mixed flow turbine

Characterization of Swirling Inflow Effects on Turbine Performance under Pulsating Flows

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Journal of Thermal Science 2022年第5期31卷 1734-1744页

作者： DING Zhanming WANG Cuicui ZHANG Junyue LIU Ying HOU Linlin ZHUGE Weilin ZHANG Yangjun Science and technology on diesel engine turbocharging laboratory China North Engine Research InstituteTianjin300400China Kangyue technology(Shandong)Co. LtdShouguangShandong262718China State key laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing100084China

The present study focuses on the influence of the swirling flows on flow behaviors and performance of a radial-flow turbocharger turbine under pulsating inflow *** characterize the effects of swirling flow,three sets of simulations of the turbine were carried out,which are an unsteady simulation under pulsating swirling inflow,an unsteady simulation under equivalent pulsating uniform inflow,and quasi-steady simulations under uniform *** proved that swirling flow has a considerable negative influence on turbine instantaneous performance and lead to 2.5%cycle-averaged efficiency reduction under pulsating flow *** inflow would lead to significant losses in both the volute and the rotor,while the pulsating inflow leads to higher losses in the rotor and shows little influence on the losses in the *** instantaneous efficiency reduction of the turbine could be correlated with the time-varying inlet swirl *** the influence of unsteady inlet swirls,the volute flow field is highly distorted and the free vortex relation is no longer *** swirling flow has strong interactions with the wake flow of the volute tongue,leading to additional *** flow angle at rotor inlet is remarkably reduced and its distribution is significantly *** separation flows and passage vortices would appear in the rotor because of the swirling inflow,leading to inferior rotor performance.

关键词： swirling inflow pulsating flow CFD turbocharger turbine internal combustion engine

Promoted catalytic property of Cu/SSZ-13 by introducing a minority of Mn for NO removal from diesel engine exhaust

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Chinese Journal of Chemical engineering 2024年第7期71卷 172-182页

作者： Runnong Yang Wuyuan Liu Zhaoying Wang Ming Sun Guangying Fu Zihan Gao Wenjian Jiao Rui Li Lin Yu Guangdong Provincial laboratory of Chemistry and Fine Chemical engineering Jieyang Center Jieyang 515200China Guangdong engineering technology Research Center of Modern Fine Chemical engineering School of Chemical Engineering and Light IndustryGuangdong University of TechnologyGuangzhou 510006China key laboratory of Bioinorganic and Synthetic Chemistry School of ChemistrySun Yat-sen UniversityGuangzhou 510275China Testing and Certification Business Department China Automotive Technology and Research Center Company LimitedWuhan 430056China Guangdong Foran technology Company Limited Foshan 528000China

The Cu-exchanged SSZ-13 with the small-pore chabazite framework is considered as a highly efficient catalyst for selective catalytic reduction of NO with NH_(3)(NH_(3)-SCR).In order to further improve the catalytic property,a series of Mn ion-assisted Cu/SSZ-13 powder catalysts were prepared by co-exchange method and stepwise exchange *** is found that the NH_(3)-SCR activity,N_(2) selectivity,hydrothermal stability and sulfur resistance of Cu/SSZ-13 are promoted by introducing a minority of Mn(0.15%to 0.23%(mass))through co-exchange *** results reveal that the Cu,Mn co-exchange enables the higher amounts of Cu^(2+)active sites,the abundant medium strong and strong acid,the optimized ratio of Lewis acid to Brønsted acid etc.,which are required for a good NH_(3)-SCR catalytic property over broad temperature range and under harsh working ***,a monolithic catalyst was prepared by impregnating a cordierite ceramic support into the coating slurry containing the optimized CuMn/SSZ-13 *** diesel engine bench tests show that Cu,Mn co-exchange gives the monolith catalyst a better catalytic property than commercial *** work provides an important guidance for the rational design of secondary-ion-assisted zeolites applied in NH_(3)-SCR.

关键词： MnCu/SSZ-13 Co-exchange Zeolite Catalysis Selective catalytic reduction