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Experimental Study on Diesel Spray and Flame Asymmetry Characteristics of Dual-Orifice Nozzles for a Medium-Speed engine

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Journal of Thermal Science 2025年第1期34卷 303-322页

作者： JU Dehao LIU Rui ZHENG Liang DENG Jiahui ZHANG Wenzheng HUO Jinlu HUANG Li Shanghai Marine Diesel engine Research institute National Key Laboratory of Marine engine Science and Technology Key Laboratory for Power Machinery and engineering Ministry of EducationShanghai Jiao Tong University

The asymmetry of the multi-orifice spray will cause uneven heat load of the marine diesel engine,thereby affecting its working performance and service ***,an in-depth understanding of the spray and flame characteristics of multi-orifice nozzles will guide the optimization of the nozzle structure,needle design and diesel atomization and combustion *** this reason,four groups of dual-orifice nozzles with different hole diameters(0.1-0.55 mm) and mass flow rates covering the typical marine medium-speed diesel injections are designed and customized,and the constant volume chamber(CVC) with high temperature and pressure is used to simulate the actual in-cylinder working conditions of the diesel engine for the spray visualization *** study the asymmetry of the fuel sprays discharged from a diesel injector,the multi-orifice nozzle is simplified as a dual-orifice nozzle in this *** with X-ray Computed Tomography(CT) imaging technology,the influences of the nozzle internal structure on the spray and flame asymmetry are studied in the constructed supercritical *** is found that the asymmetry of the inlet angle and the equivalent length-diameter ratio is positively correlated with the inconsistency of the dual *** an increase in the injection pressure and nozzle diameter,the asymmetry of the dual spray becomes more pronounced,resulting in greater disparities in the ignition delay times and ignition positions of the two ***,the increase in nozzle diameter also leads to combustion instability,resulting in a flame with a serrated *** the increase of ambient temperature,the proportion of liquid phase in the jet decreases and the relative density of spray front decreases.

关键词： atomization dual-orifice nozzle nozzle structure spray flame asymmetry

Design and application of an air-cooled probe for total pressure measurement at combustor outlet

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航空动力学报 2019年第1期34卷 34-44页

作者： LIU Xupeng SUN Qi WANG Xiaoliang XUE Xiusheng YIN Dong Shenyang engine Research institute Aero Engine Corporation of China

An air-cooled probe was designed for measurement of total pressure at combustor outlet;its cooling scheme combined the film cooling and convection *** the aid of CFD technique,cooling effectiveness of the coolant jets at various blow ratios was compared;suitable blow ratios and configuration of film holes were chosen *** overall cooling performance of the probe was evaluated via CFD technique,the design was improved according to the simulation result,and the cooling effect of the leading edge was obviously strengthened by increasing the local coolant mass flow *** results of wind tunnel test indicated that,between Mach numbers 0.2 and 0.4,the probe achieved a high accuracy at various attack *** probe was utilized in an annular combustor rig test,the highest temperature reached 1 760 Kand total pressure reaches 1 036 *** result of rig test demonstrates that the coolant film distribution consistent appropriately with the CFD results.

关键词： high temperature measurement total pressure probe film cooling CFD combustor outlet

Review of Numerical Simulation of TGO Growth in Thermal Barrier Coatings

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Computer Modeling in engineering & Sciences 2022年第8期132卷 361-391页

作者： Quan Wen Fulei Jing Changxian Zhang Shibai Tang Junjie Yang aero engine Academy of China Aero Engine(Group)Corporation of ChinaBeijing101304China institute for aero engine Tsinghua UniversityBeijing100084China

Thermally grown oxide(TGO)is a critical factor for the service life of thermal barrier coatings(TBC).Numerical simulations of the growth process of TGO have become an effective means of comprehensively understanding the progressive damage of the TBC *** present,technologies of numerical simulation to TGO growth include two categories:coupled chemical-mechanical methods and mechanical equivalent *** former is based on the diffusion analysis of oxidizing elements,which can describe the influence of bond coat(BC)consumption and phase transformation in the growth process of TGO on the mechanical behavior of each layer of TBC,and has high accuracy for the thickness evolution of TGO,but they cannot describe the lateral growth of TGO and the rumpling phenomenon *** latter focuses on describing the final stress and strain state after the growth of a specific TGO rather than the complete growth processes of *** on the measured TGO thickness growth curve,simulations of thickening and lateral growth can be achieved by directly applying anisotropic volumetric strain to oxidized elements and switching elements properties from the BC to the TGO.

关键词： Thermal grown oxide(TGO) numerical simulation thermal barriers coatings(TBC) finite element method lateral growth

Influence Factors for Impact Actions and Transient Trajectories of Fan Blades after Fan Blade Out in Typical 2-Shaft High Bypass Ratio Turbofan engine

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Journal of Thermal Science 2022年第1期31卷 96-110页

作者： XU Xue LI Hongxin FENG Guoquan Shenyang engine Research institute Aero Engine Corporation of ChinaShenyang 110015China Corporation Headquarter Aero Engine Corporation of ChinaBeijing 100097China

To enhance the understanding of design characters, which have prominent influences during the fan blade out event, a simplified geometrical and dynamic analysis method was derived, and a typical 2-shaft high bypass ratio turbofan engine was selected and modeled. Based on analytical deriving and engineering experience learned from the real engine failure case, three determinative impact actions were recognized from the fan blade out process. The transient trajectories of these impact actions were researched in analytical method, and then thickness of acoustic lining, quantity of fan blades and threshold load of structural fuse were analyzed as key design characters. 36 serialized fan blade out transient dynamic simulations were conducted by using the 2-shaft high bypass ratio turbofan engine model within different combinations of the three key design factors. The results from geometrical and dynamic analysis matched mainly well with the results from simulations. Characteristic phenomenon in simulation can be explained theoretically. Five conclusions can be summarized from these results. (1) If thickness fan acoustic lining was thinner, the deviation between simplified analytical calculation and simulation were not outstanding to predict Blade-Casing the first impact time and angular position. (2) An appropriate thickness of acoustic lining could make a lower impact stress of fan casing at the first impact. (3) Different thickness of acoustic linings leaded to two impact modes for blade 2, which were tip impact and root impact. (4) Different impact conditions between blade 1 and blade 2 caused remarkable speed components distinction of blade 1, and leaded to a wide range of transient trajectory of blade 1 during FBO event. (5) Thicker acoustic lining in this research can usually find the porper threshold loads setting, which can give a satisfactory outbound vibration. Two details were raised for further research, which were impact behavior of composite material fan bl

关键词： fan blade out transient trajectory design character structural fuse high bypass ratio turbofan

Exploration of acceptable operating range for a compression system in a double bypass engine

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Chinese Journal of aeronautics 2023年第9期36卷 111-122页

作者： Ruoyu WANG Xianjun YU Baojie LIU Guangfeng AN Research institute of aero-engine Beihang UniversityBeijing 102206China National Key Laboratory of Science and Technology on aero-engine aero-Thermodynamics Beijing 102206China

The variable cycle engine is distinguished by its highly adjustable compression system,whose aerodynamic characteristic is extremely *** explore the regulation range of a double bypass engine compression system,a multi-dimensional analysis method is developed,through which the coupling mechanism between the compressor component and the bypass is *** operation zones of the compressor components and the bypass system are proposed,and the operation range of the compression system is obtained by calculating the overlapping part of the operation *** results show that in the double bypass mode,there exists a minimum mode selector valve area and a minimum core driven fan stage stall margin that ensures a feasible bypass flow,the two parameters correspond to each *** the given fan and core driven fan stage conditions,the maximum value of the inner bypass ratio is restricted by the upper limit of the forward variable area bypass injector and the maximum Mach number in the total bypass,while the minimum value of the inner bypass ratio depends on the lower limit of the forward variable area bypass injector geometry and the system recirculation *** single bypass mode is a unique condition of the double bypass mode,as the operation zone of the compressor component degenerates from a two-dimensional surface to a straight *** are multiple bypass states available in the single bypass mode,while the regulation range of the bypass ratio is jointly restricted by the operation range of the high pressure compressor and the aerodynamic boundary of the forward variable area bypass injector.

关键词： Compression system Coupling effect Matching mechanism Multi-dimensional method Operation range Variable cycle engine

Stress-controlled LCF experiments and ratcheting behaviour simulation of a nickel-based single crystal superalloy with [001] orientation

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Chinese Journal of aeronautics 2021年第8期34卷 112-121页

作者： Bin ZHANG Rongqiao WANG Dianyin HU Kanghe JIANG Jianxing MAO Fulei JING Xinyi HAO School of Energy Power EngineeringBeihang UniversityBeijing 100083China Beijing Key Laboratory of aero-engine Structure and Strength Beijing 100083China Research institute of aero-engine Beihang UniversityBeijing 100083China Hunan Aviation Powerplant Research institute Aero Engine(Group)Corporation of ChinaZhuzhou 412002China aero engine Academy of China Aero Engine(Group)Corporation of ChinaBeijing 101304China

Uniaxial ratcheting behaviour and low cycle fatigue(LCF)failure mechanism of nickel-based single crystal superalloy DD6 with[001]orientation are investigated through the stresscontrolled LCF tests with stress ratio *** the deformation behaviour during the wholelifetime from the beginning of the experiment to the fracture of the specimen,as well as the fractographic/metallographic morphology,are compared with the strain-controlled LCF experimental *** the scanning electron microscope(SEM)observations,it is shown that the failure characteristics under stress-controlled LCF loading are similar with those under strain-controlled ***,unlike strain-controlled LCF loading,even under fully reversed cycle loading for stress-controlled LCF,DD6 shows significant ratcheting behaviour due to the tensioncompression *** addition,the LCF lifetimes under stress control are significantly shorter than the LCF lifetimes under strain control,and the culprit might be the detrimental effect of ratcheting strain on LCF *** on these phenomena,an improved crystal plasticity constitutive model on the basis of slip-based Walker constitutive model is developed through modifying the kinematic hardening rule in order to overcome the inaccurate prediction of decelerating stageand stable stage of ratcheting ***,combining the continuum damage mechanics,a damage-coupled crystal plasticity constitutive model is proposed to reflect the damage behaviour of DD6 and the accelerating stage of ratcheting *** simulation results for the stress-controlled LCF deformation behaviour including the whole-lifetime ratcheting behaviour show good agreement with the experimental data.

关键词： Crystal plasticity constitutive model Low cycle fatigue Nickel-based single crystal superalloy Ratcheting behaviour Stress-controlled experiment

Development of a deviation package method for low-cost robust optimization in compressor blade design

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Chinese Journal of aeronautics 2024年第4期37卷 166-180页

作者： Mingzhi LI Xianjun YU Dejun MENG Guangfeng AN Baojie LIU Research institute of aero-engine Beihang UniversityBeijing 100191China National Key Laboratory of Science&Technology on aero-engine aero-Thermodynamics Beihang UniversityBeijing 100191China AECC Shenyang engine Research institute Shenyang 110015China

Manufacture variations can greatly increase the performance variability of compressor blades. Current robust design optimization methods have a critical role in reducing the adverse impact of the variations, but can be affected by errors if the assumptions of the deviation models and distribution parameters are inaccurate. A new approach for robust design optimization without the employment of the deviation models is proposed. The deviation package method and the interval estimation method are exploited in this new approach. Simultaneously, a stratified strategy is used to reduce the computational cost and assure the optimization accuracy. The test case employed for this study is a typical transonic compressor blade profile, which resembles most of the manufacture features of modern compressor blades. A set of 96 newly manufactured blades was measured using a coordinate measurement machine to obtain the manufacture variations and produce a deviation package. The optimization results show that the scatter of the aerodynamic performance for the optimal robust design is 20% less than the baseline value. By comparing the optimization results obtained from the deviation package method with those obtained from widely-used methods employing the deviation model, the efficiency and accuracy of the deviation package method are demonstrated. Finally, the physical mechanisms that control the robustness of different designs were further investigated, and some statistical laws of robust design were extracted.

关键词： Manufacture variations Robust design optimization Compressor leading edge aerodynamics Physical mechanism

Breaking the geometry-performance tradeoff in compressor deviation modeling:Nested principal component analysis

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Chinese Journal of aeronautics 2024年第9期37卷 131-149页

Uncertainties in the aerodynamic performance of compressors,introduced by manufacturing variations,have received more and more attentions in recent *** deviation model plays a crucial role in evaluating this uncertainty and facilitating robust ***,current deviation models with a few variables cannot simultaneously achieve a precise geometric approximation of deviation and provide an accurate assessment of performance *** paper introduces a novel deviation modeling method named Nested Principal Component Analysis(NPCA)to break this *** this method,both geometry-based and performance-based modes are utilized to describe manufacturing *** considering aerodynamic sensitivity,surface deformations that significantly impact aerodynamic performance can be extracted for deviation *** demonstrate the superiority of this newly proposed method,ninety-eight newly manufactured compressor rotor blades were measured using a coordinate measurement machine,and both NPCA and Principal Component Analysis(PCA)were employed to model the real manufacturing *** results indicate that,in comparison to the PCA method,the NPCA method achieves an equivalent level of accuracy in geometric reconstruction and evaluation of mean ***,the same level of accuracy can be obtained with eight NPCA modes and fifty PCA modes when assessing the scatter in aerodynamic ***,the working mechanism of the NPCA method for accurate uncertainty quantification was further investigated.

关键词： Manufacturing variation Uncertainty quantification Dimension reduction aerodynamics Flow mechanism

Development of secondary flow field under rotating condition in a straight channel with square cross-section

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Chinese Journal of aeronautics 2018年第8期31卷 1703-1715页

作者： Ruquan YOU Kuan WEI Zhi TAO Haiwang LI Guoqiang XU National Key Laboratory of Science and Technology on aero-engines aero-Thermodynamics Beihang University Collaborative Innovation Center for Advanced aero-engine Beihang University aero engine Academy of China Aero Engine (Group) Corporation of China

The developing secondary flow fields in the entrance section of a rotating straight channel were experimentally investigated using Particle Image Velocimetry（PIV）. The effects of streamwise position, Reynolds number and rotation number on the development of the secondary flow fields were revealed. The results show that the absolute values of vorticity flux of the trailing side roll cells increase with increasing radius of the measured plane and rotation number. When the absolute value of vorticity flux exceeds a critical value, the merging of the trailing side roll cells appears. Moreover, when the number of the trailing side vortex pairs is even, the absolute values of vorticity flux of the leading side vortices increase along streamwise direction. Otherwise, the absolute values decrease along the streamwise direction. By the circulation analysis, this phenomenon was found to have relationship with the merging of the trailing side roll cells, and further concluded that the secondary flow field in a rotating channel has to be treated as a whole. At last,the increase of the Reynolds number was found to be able to induce the merging position moves upstream.

关键词： Circulation analysis Entrance section Field Programmable GataArray (FPGA) Particle Image Velocimetry(PlV) Rotating channel Secondary flow