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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

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

Uncertainties in the aerodynamic performance of compressors,introduced by manufac-turing 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 approxi-mation 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 man-ufactured compressor rotor blades were measured using a coordinate measurement machine,and both NPCA and Principal Component Analysis(PCA)were employed to model the real manufac-turing *** 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 mecha-nism of the NPCA method for accurate uncertainty quantification was further investigated.

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

The aeroelastic effects on the scatter phenomenon of wind-tunnel data

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Science China(Technological Sciences) 2013年第2期56卷 405-415页

作者： YE ZhengYin JIANG YueWen ZHOU NaiZhen SONG BaoFang HE JiZhou State key laboratory of Science and Technology on aerodynamic Design and Research Northwestern Polytechnical University

The unsteady Reynolds-averaged Navier-Stokes equations coupled with the k-co SST turbulence model are solved to obtain the steady and unsteady aerodynamic forces for airfoils and wings. The effects of vibration types and amplitudes on aerody- namic forces of airfoils and wings are studied. The deformation characteristics of a swept wing induced by steady aerodynamic load are presented. It is found that for a vibrating elastic wing at small and medium incidences, its mean aerodynamic loads are almost the same as those obtained from the static one. On the contrary, at high incidences especially around the stall incidence, the vibration may change the mean values. In addition, the larger amplitude is, the larger discrepancy will be. For a swept wing, the steady aerodynamic loads usually lead to the ＂pitching down＂ effect on the wing tip which delays the stall compared with a rigid one; But this phenomenon dose not occur on a aeroelastic wing which can induce the separation ahead and trigger the stall. The above conclusions are in good agreement with the scatter characteristics of wind-tunnel data. The reason why the data obtained from wind tunnel and CFD are different is also analyzed. Meanwhile, it can be an explanation for scatter phe- nomenon of wind-tunnel data, especially for high incidence cases, which remains a puzzle so far.

关键词： separation stall aeroelastic scatter phenomenon for wind-tunnel data

Feedback control of boundary layer Tollmien-Schlichting waves using a simple model-based controller

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Chinese Journal of Aeronautics 2021年第3期34卷 25-38页

作者： Yong LI Zhengwu CHEN School of Mechanical and Electrical Engineering Wenzhou UniversityWenzhou 325035China key laboratory of aerodynamic Noise Control China Aerodynamic Research and Development CenterMianyang 621000China

The attenuation of spatially evolving instability Tollmien-Schlichting(T-S)waves in the boundary layer of a flat plate with zero pressure gradients using an active feedback control scheme is theoretically and numerically *** boundary layer is excited artificially by various perturbations to create a three-dimensional field of instability *** of actuators and sensors are distributed locally at the wall surface and connected together via a feedback *** key elements of this feedback control are the determination of the dynamic model of the flat plate boundary layer between the actuators and the sensors,and the design of the model-based feedback *** dynamic model is established based on the linear stability calculation which simulates the three-dimensional input-output behaviour of the boundary *** simplify the control problem,an uncoupled control mode of the dynamic model is made to capture only those dynamics that have greatest influences on the input-output behaviour.A Proportional-Integral-Derivative(PID)controller,i.e.a lead-lag compensator,combining with a standard Smith predictor is designed based on the system stability criterion and the specifications using frequency-response *** performance of the feedback control with the uncoupled control mode is demonstrated by the large reduction of the three-dimensional disturbances in the boundary *** simple feedback control is realistic and competitive in a practical implementation of T-S wave cancellation using a limited number of localised sensors and actuators.

关键词： Boundary layer instability Control system Feedback control PID controller Tollmien-Schlichting waves

Air flow patterns and noise analysis inside high speed angular contact ball bearings

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Journal of Central South University 2015年第9期22卷 3358-3366页

作者：翟强闫柯张优云朱永生王亚泰 key laboratory for Modern Design and rotor Bearing System of Ministry of Education (Xi’an Jiaotong University)

The vortex formed around the rolling ball and the high pressure region formed around the ball-raceway contact zone are the principle factors that barricades the lubricant entering the bearing cavity, and further causes improper lubrication. The investigation of the air phase flow inside the bearing cavity is essential for the optimization of the oil-air two-phase lubrication method. With the revolutionary reference frame describing the bearing motion, a highly precise air phase flow model inside the angular contact ball bearing cavity was build up. Comprehensive factors such as bearing revolution, ball rotation, and cage structure were considered to investigate the influences on the air phase flow and heat transfer efficiency. The aerodynamic noise was also analyzed. The result shows that the ball spinning leads to the pressure rise and uneven pressure distribution. The air phase velocity, pressure and cage heat transfer efficiency increase as the revolving speed increases. The operating noise is largely due to the impact of the high speed external flow on the bearing. When the center of the oil-air outlet fixes near the inner ring, the aerodynamic noise is reduced. The position near the inner ring on the bigger axial side is the ideal position to fix the lubricating device for the angular contact ball bearing.

关键词： high speed angular contact ball bearing air phase flow heat transfer efficiency cage structure

The stability analysis of rolling motion of hypersonic vehicles and its validations

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Science China(Physics,Mechanics & Astronomy) 2014年第12期57卷 2194-2204页

作者： YE YouDa ZHAO ZhongLiang TIAN Hao ZHANG XianFeng State key laboratory of aerodynamics China Aerodynamic Research and Development Center National laboratory for Computational Fluid Dynamics High Speed Institute of China aerodynamic Research and Development Center

The stability of the rolling motion of near space hypersonic vehicles with rudder control is studied using method of qualitative analysis of nonlinear differential equations, and the stability criteria of the deflected rolling motions are improved. The out- comes can serve as the basis for further study regarding the influence of pitching and lateral motion on the stability of rolling motion. To validate the theoretical results, numerical simulations were do^e for the rolling motion of two hypersonic vehicles with typical configurations. Also, wind tunnel experiments for four aircraft models with typical configurations have been done. The results show that： 1） there exist two dynamic patterns of the rolling motion under statically stable condition. The first one is point attractor, for which the motion of aircraft returns to the original state. The second is periodic attractor, for which the aircraft rolls periodically. 2） Under statically unstable condition, there exist three dynamic patterns of rolling motion, namely, the point attractor, periodic attractor around deflected state of rolling motion, and double periodic attractors or chaotic attrac- tors.

关键词： rolling motion stability criterion numerical simulation wind tunnel experiment

Highly reversible photomodulated hydrosoluble stiff-stilbene supramolecular luminophor induced by cucurbituril

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Chinese Chemical Letters 2024年第8期35卷 235-239页

作者： Guoxing Liu Yixin Li Changming Tian Yongmei Xiao Lijie Liu Zhanqi Cao Song Jiang Xin Zheng Caoyuan Niu Yun-Lai Ren Liangru Yang Xianfu Zheng Yong Chen College of Science Henan Agricultural UniversityZhengzhou 450002China College of Chemistry and Chemical Engineering Henan University of TechnologyZhengzhou 450001China College of Chemistry State Key Laboratory of Elemento-Organic ChemistryNankai UniversityTianjin 300071China

A photochromic molecular rotor based on stiff-stilbene(SSB-FMR)was handily prepared through coupled reaction,and further self-assembled with cucurbit[8]uril(CB[8])to form a 2:2 quaternary supramolecu-lar complex(SSB-FMR/CB[8]).Significantly,the intervention of CB[8]on SSB-FMR achieved dual functions that assembly-induced emission enhancement and assembly-induced improvement of photoisomerized performance(especially reversibility)of stiff-stilbene molecular *** supramolecular strategy further facilitated the assembly as a photoresponsive fluorescence switch with outstanding fatigue resis-tance,which was expediently applied in high-security-level QR code anti-counterfeiting and controllable lysosome targeted *** study unprecedentedly provides a supramolecular method for highly effi-ciently improving photoisomerized performance especially reversibility of molecular photoswitches based on stiff-stilbene,and is of vital significance for the construction of intelligent materials with excellent ca-pability.

关键词： Host-guest complexation Cucurbituril Fluorescence switch Stiff-stilbene Fluorescence enhancement

Influence of Particles on the Loading Capacity and the Temperature Rise of Water Film in Ultra-high Speed Hybrid Bearing

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Chinese Journal of Mechanical Engineering 2015年第3期28卷 541-548页

作者： ZHU Aibin LI Pei ZHANG Yefan CHEN Wei YUAN Xiaoyang key laboratory of Education Ministry for Modern Design and rotor-Bearing System Xi'an Jiaotong University

Ultra-high speed machining technology enables high efficiency, high precision and high integrity of machined surface. Previous researches of hybrid bearing rarely consider influences of solid particles in lubricant and ultra-high speed of hybrid bearing, which cannot be ignored under the high speed and micro-space conditions of ultra-high speed water-lubricated hybrid bearing. Considering the impact of solid particles in lubricant, turbulence and temperature viscosity effects of lubricant, the influences of particles on pressure distribution, loading capacity and the temperature rise of the lubricant film with four-step-cavity ultra-high speed water-lubricated hybrid bearing are presented in the paper. The results show that loading capacity of the hybrid bearing can be affected by changing the viscosity of the lubricant, and large particles can improve the bearing loading capacity higher. The impact of water film temperature rise produced by solid particles in lubricant is related with particle diameter and minimum film thickness. Compared with the soft particles, hard particles cause the more increasing of water film temperature rise and loading capacity. When the speed of hybrid bearing increases, the impact of solid particles on hybrid bearing becomes increasingly apparent, especially for ultra-high speed water-lubricated hybrid bearing. This research presents influences of solid particles on the loading capacity and the temperature rise of water film in ultra-high speed hybrid bearings, the research conclusions provide a new method to evaluate the influence of solid particles in lubricant of ultra-high speed water-lubricated hybrid bearing, which is important to performance calculation of ultra-high speed hybrid bearings, design of filtration system, and safe operation of ultra-high speed hybrid bearings.

关键词： hybrid bearing liquid-solid flow solid particles loading capacity temperature rise

Unified Coordinate System Model for Performance Calculation of Fix-pad Journal Bearing with Different Pad Preload

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Chinese Journal of Mechanical Engineering 2014年第3期27卷 537-542页

作者： ZHU Aibin YANG Yulei CHEN Wei YUAN Xiaoyang key laboratory of Education Ministry for Modern Design and rotor-Bearing System Xi'an Jiaotong University

Traditional model for calculating performance parameters of a fix-pad journal bearing leads to heavy workload, complicated and changeable formulae as it requires deriving various geometric formulae with different bearing types such as circular journal bearing, dislocated bearing and elliptic bearing. Considering different pad preload ratios for non-standard bearing, traditional model not only becomes more complicated but also reduces scalability and promotion of the calculation programs. For the complexly case of traditional model while dealing with various fix-pad journal bearings, unified coordinate system model for performance calculation of fix-pad journal bearing is presented in the paper. A unified coordinate system with the bearing center at the origin is established, and the eccentricity ratio and attitude angle of axis relative to each pad are calculated through the coordinates of journal center and each pad center. Geometric description of fix-pad journal bearing is unified in this model, which can be used for both various standard bearing and non-standard bearing with different pad preload ratios. Validity of this model is verified with an elliptical bearing. Performance of a non-standard four-leaf bearing with different pad preload ratios is calculated based on this model. The calculation result shows that increasing preload ratio of the pad 1 and keeping that of the left three pads constant improves bearing capacity, stiffness and damping coefficients. This research presents a unified coordinate system model unifies performance calculation of fix-pad journal bearings and studied a non-standard four-leaf bearing with different pad preload ratios, the research conclusions provides new methods for performance calculation of fix-pad journal bearings.

关键词： fix-pad journal bearing performance calculation unified coordinate system model

A new grid deformation technology with high quality and robustness based on quaternion

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Chinese Journal of Aeronautics 2014年第5期27卷 1078-1085页

作者： Huang Jiangtao Gao Zhenghong Wang Chao China aerodynamics Research and Development Center National key laboratory of aerodynamic Design and Research Northwestern Polytechnical University

Quality and robustness of grid deformation is of the most importance in the field of aircraft design, and grid in high quality is essential for improving the precision of numerical simulation. In order to maintain the orthogonality of deformed grid, the displacement of grid points is divided into rotational and translational parts in this paper, and inverse distance weighted interpolation is used to transfer the changing location from boundary grid to the spatial grid. Moreover, the deformation of rotational part is implemented in combination with the exponential space mapping that improves the certainty and stability of quaternion interpolation. Furthermore, the new grid deformation technique named ‘‘layering blend deformation＇＇ is built based on the basic quaternion technique, which combines the layering arithmetic with transfinite interpolation（TFI） technique. Then the proposed technique is applied in the movement of airfoil, parametric modeling, and the deformation of complex configuration, in which the robustness of grid quality is tested. The results show that the new method has the capacity to deal with the problems with large deformation, and the ‘‘layering blend deformation＇＇ improves the efficiency and quality of the basic quaternion deformation method significantly.

关键词： Basis quaternion grid deformation Exponential mapping Inverse distance weighting(IDW) Lie algebra space Transfinite interpolation