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Preparation and characterization of LPPS NiCoCrAlYTa coatings for gas turbine engine

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中国有色金属学会会刊：英文版 2001年第4期11卷 567-571页

作者：洪瑞江周克崧王德政朱晖朝邝子奇 Guangzhou Res Inst Nonferrous Met Guangzhou 510651 Peoples R China

NiCoCrAlYTa coatings have been deposited onto an aircraft gas turbine engine blade using a LPPS unit equipped with a computerized robot. Optimal processing conditions, including spray parameters, the trajectory of the robot, and the synchronized movements between the torch and the blade, have been developed for superior coating properties. Transferred arc treatment, providing a preheating and a cleaning of the substrate surface, enhances the adherence of the coatings to the substrate. The resulting LPPS coatings show dense and uniform characteristics with ideal hardness, and good corrosion resistance to cycle oxidation.

关键词： low pressure plasma spraying hot corrosion coating gas turbine engine MCrAlY

Numerical simulation method of surge experiments on gas turbine engines

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Chinese Journal of Aeronautics 2023年第3期36卷 107-120页

作者： Xinqian ZHENG Hanxuan ZENG Baotong WANG Mengyang WEN Heli YANG Zhenzhong SUN School of Vehicle and Mobility Tsinghua UniversityBeijing 100084China Institute for Aero engine Tsinghua UniversityBeijing 100084China

In order to obtain the surge margin of an aero-engine during its operation,an engine surge experiment is required.A multi-dimensional simulation method for an aero-engine is established in this *** simulation of a surge experiment using high-pressure air-injection is then carried out on a turbo-shaft engine to obtain the surge boundary using this *** specifically,firstly,a body-force model is employed to calculate the compressor performance owing to its capability of capturing the main three-dimensional features of compressor surge and avoiding excessive simulation time required by the traditional fully-three-dimensional Reynolds Averaged Navier-Stokes(RANS)***,a one-dimensional model combining a lumped-parameter plenum model is used for the combustor to account for the propagation of pressure waves and the heat-release process,and a zero-dimensional throttle model is used to mimic the choking effect at the turbine ***,the air-injection system is modeled by imposing an injection boundary condition,which can be used conveniently in changing injection *** on the established method,the influences of different test parameters,such as the air-injection location,the pressure,the orifice size,the number of injection orifices,and the injection time duration on the surge characteristics and boundary are further studied,which offer effective guidance to optimize an actual experimental design.

关键词： Air-injection Body-force model gas turbine engine Numerical method Surge experiment

Experimental study on impacts of fuel type on thermo-acoustic instability in a gas turbine model combustor

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Science China(Technological Sciences) 2021年第6期64卷 1345-1358页

作者： RUAN Can CHEN FeiEr YU Tao CAI WeiWei HE ZhuoYao MAO YeBing LI XinLing LU XingCai School of Mechanical engineering Shanghai Jiao Tong UniversityShanghai 200240China

Effects of liquid fuel composition variations on characteristics of self-excited thermo-acoustic instabilities in a lean premixed,pre-vaporized gas turbine model combustor were experimentally *** fuels included practical RP-3 jet fuel and its blending with iso-octane and n-dodecane,which were branched and linear alkanes *** the test conditions,dynamic pressure measurements indicated that the dominant instability frequency was highest for RP-3 flame,while RP-3/ndodecane flame exhibited the strongest instability strength.A further analysis showed that the instability frequency correlated well with the profiles of adiabatic flame temperature,and the strength of the instability highly depended on the ignition delay times of the *** of the flame structure and flow field with OH*chemiluminescence (CL) imaging and twodimensional particle image velocimetry (PIV) techniques indicated that changes in the fuel composition did not alter the unstable modes and general sequences of flame-flow structure *** power spectra and proper orthogonal decomposition(POD) analysis suggested that axial oscillations along with precessing vortex core (PVC) induced helical motion predominated periodic flame structure and flow field oscillations.

关键词： combustion gas turbine engine fuel effects thermo-acoustic instability PIV

Reduced-dimensional MPC controller for direct thrust control

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Chinese Journal of Aeronautics 2022年第4期35卷 66-81页

With the development of the aircraft gas turbine engine, a control system should be able to achieve effective thrust control to gain better operability. The main contribution of this paper is to develop a novel direct thrust control approach based on an improved model predictive control method through a strategy that reduces the dimension of control sequence. It can not only achieve normal direct thrust control tasks but also maximize the thrust level within the safe operation boundaries. Only the action of switching the objective functions is required to achieve the switch of these two thrust control modes while there is no modification to the control structure. Besides,a shorter control sequence is defined for multivariable control by updating only one control variable at every simulation time instant. Therefore, the time requirement for the solving process of the optimal control sequence is reduced. The proposed controller is implemented to a twin-spool *** are conducted in the wide flight envelope, and results show that the average timeconsumption can be reduced up to 65% in comparison with the standard model predictive control,and the thrust can be increased significantly when maximum thrust mode is implemented by using engine limit margins.

关键词： Computation time Direct thrust control gas turbine engine Model predictive control Thrust optimization

A double integral method for quantitative evaluation of influence on thin-walled casing response caused by bearing uncertainties

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Chinese Journal of Aeronautics 2020年第9期33卷 2372-2381页

作者： Binbin GENG Yanfei ZUO Zhinong JIANG Kun FENG Chen WANG Jie WANG Key Lab of engine Health Monitoring-Conlrol and Netw orking of Ministry of Education Beijing University of Chemical TechnologyBeijing 100029China Beijing Key Laboratory of High-end Mechanical Equipment Health Monitoring and Self-Recovery Beijing University of Chemical TechnologyBeijing 100029China

Bearings in a gas turbine engine are the key connecting components transmitting force and motion between rotors and thin-walled flexible *** bearing stiffness and damping of squeeze film damper(SFD)nearby bearings are easily affected by many factors,such as assembly process,load condition and temperature variation,resulting in *** uncertainties may influence the response of the measuring point on the ***,it is difficult to carry out the fault diagnosis,whole machine balancing and other related *** this paper,a double integral quantitative evaluation method is proposed to simultaneously analyze the influence of two uncertain dynamic coefficients on the response amplitude and phase of casing measuring ***,the coupling influence of stiffness and damping accompanied by dramatic changes with rotational speeds are essentially *** an example,a typical engine bearing-casing system with complex dynamic characteristics is *** impact of uncertain dynamic coefficients on the unbalance response is quantitatively evaluated.

关键词： Dynamic coefficients gas turbine engine Measuring point response Quantitative evaluation Uncertainty analysis

Sequential ensemble optimization based on general surrogate model prediction variance and its application on engine acceleration schedule design

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Chinese Journal of Aeronautics 2021年第8期34卷 16-33页

作者： Yifan YE Zhanxue WANG Xiaobo ZHANG Shannxi Key Laboratory of Internal Aerodynamic in Aero-engine School of Power and EnergyNorthwestern Polytechnical UniversityXi'an 710072China

The Efficient Global Optimization(EGO)algorithm has been widely used in the numerical design optimization of engineering ***,the need for an uncertainty estimator limits the selection of a surrogate *** this paper,a Sequential Ensemble Optimization(SEO)algorithm based on the ensemble model is *** the proposed algorithm,there is no limitation on the selection of an individual surrogate ***,the SEO is built based on the EGO by extending the EGO algorithm so that it can be used in combination with the ensemble ***,a new uncertainty estimator for any surrogate model named the General Uncertainty Estimator(GUE)is *** performance of the proposed SEO algorithm is verified by the simulations using ten well-known mathematical functions with varying *** results show that the proposed SEO algorithm performs better than the traditional EGO algorithm in terms of both the final optimization results and the convergence ***,the proposed algorithm is applied to the global optimization control for turbo-fan engine acceleration schedule design.

关键词： Cross-validation Efficient global optimization engine acceleration schedule design Ensemble of surrogate models gas turbine engine Optimization methods Surrogate-based optimization

Mathematical simulation of low cycle fatigue of high-loaded engine parts

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Propulsion and Power Research 2018年第4期7卷 277-287页

作者： Yury M.Temis Central Institute of Aviation Motors 2 Aviamotornaya st.Moscow 111116Russia

The paper discusses main aspects of low cycle fatigue influence on the lifetime ofengine *** importance and history of the problem,the main experiments and the effectsimpacting the low cycle fatigue of structural materials are described.A hypothesis about theexistence of a thermomechanical surface of structural material,generalized to the case of acyclical loading was used to approximate the loops of cyclic nonisothermal elastoplasticdeformation *** cyclic deformation curve model is based on the following threeparameters:the elastic modulus during unloading,the Bauschinger effect and the conversionparameter of the nonlinear part of its first *** model also accounts for theaccumulated plastic strain,as well as the testing *** criterion of durability isformulated,based on the dependence between the number of halfcycles to failure and theaccumulated plastic *** theory of plasticity,generalized to the case ofcyclic deformation,in combination with the durability model and technology of"dying"elements is applied to the finite element analysis of low cycle fatigue of gas turbine *** results of calculations are demonstrated.

关键词： gas turbine engine Low cycle fatigue Nonisothermal plasticity Finite element modeling Durability modeling Cyclic loading