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MULTI-OBJECTIVE OPTIMIZATION DESIGN FOR TRANSONIC TURBINE CASCADES USING SIMULATED ANNEALING ALGORITHM

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Journal of Hydrodynamics 1999年第2期11卷 20-25页

作者： tong tong feng Zhen-ping(Institute of Turbomachinery, xi’an jiaotong university, xi’an 71OO49, P. R. China) xi'an jiaotong Univ Xi'an China

On the basis of computational of transonic viscid flow, the simulated annealing algorithm, used in statistical mechanics to study solid cooling process, is adaptedfor soving multi-objective cascades design problem. The simulated annealing algorithmdraws an analogy between the energy minimization in physical system and the objectivefunction in the real design problem, To model the multi-objective functions, a minimumdeviation method is used. In this paper, the loss and work are considered as the objectivefunctions. Simulated results indicate that this algorithm can be effectively applied to theimprovement of the design for transonic turbine cascades.

关键词： simulated annealing algorithm (SAA) turbine cascades multi-objective optimization

Transonic flow of moist air around an NACA 0012 airfoil with non-equilibrium condensation

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Progress in Natural Science:Materials International 2005年第9期15卷 838-842页

作者： LI Liang**, SUN xiuling, feng zhenping and LI Guojun(School of Energy & Power Engineering, xi’an Jiao tong university, xi’an 710049, China) School of Energy and Power Engineering Xi'an Jiaotong University Xi'an 710049 China

The classical condensation model of water vapor is coupled with the Euler equations to calculate transonic flows of moist air with non-equilibrium condensation. By means of this model, numerical computations are implemented to investigate the aerodynamic characteristics of an NACA 0012 airfoil in transonic flows of moist air at various angles of attack and relative humidities, and the results are compared with those in dry air flows. For different angles of attack considered at 50% relative humidity, the lift decreases 30%—40%. The pressure drag increases when the angle of attack is smaller than 1.4° and decreases when higher than 1.4°. At zero angle of attack, with the relative humidity rising from zero to 90%, the pressure drag increases exponentially. At 90% relative humidity, the pressure drag increases 160%, and self-oscillation takes place periodically and alternately over the upper and lower surfaces of the airfoil. The oscillation is caused by the interactions of local supersonic flow and heat release in the condensation process.

关键词： NACA 0012 airfoil moist air non-equilibrium condensation.

Numerical investigation on the self-excited oscillation of wet steam flow in a supersonic turbine cascade

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Progress in Natural Science:Materials International 2006年第9期16卷 988-992页

作者： LI Liang, SUN xiuling, LI Guojun and feng zhenping (School of Energy & Power Engineering, xi’an jiaotong university, xi’an 710049, China) School of Energy and Power Engineering Xi'an Jiaotong University Xi'an 710049 China

The self-excited flow oscillation due to supercritical heat addition during the condensation process in wet steam turbine is an important issue. With an Eulerian/Eulerian model, the self-excited oscillation of wet steam flow in a supersonic turbine cascade is investigated . A proper inlet supercooling results in the transition from steady flow to self-excited oscillating flow in the cascade of steam turbine. The frequency dependency on the inlet supercooling is not monotonic. The flow oscillation leads to non-synchronous periodical variation of the inlet and outlet mass flow rate. The aerodynamic force on the blade varies periodically due to the self-excited flow oscillation. With the frequency lies between 18.1-80.64 Hz, the oscillating flow is apt to act with the periodical variation of the inlet supercooling due to sta-tor rotor interaction in a syntonic pattern, and results in larger aerodynamic force on the blade. The loss in the oscillating flow increases 20.64% compared with that in the steady flow.

关键词： self-excited oscillation wet steam turbine cascade condensation.

Aerodynamic Optimum Design of Transonic Turbine Cascades Using Genetic Algorithms

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Journal of Thermal Science 1997年第2期6卷 111-116页

作者： Li Jun feng zhenping Chang Jianzhong Shen Zuda(Institute of Turbomachinery, School of Energy & Power Engineering, xi’an jiaotong university,xi’an, Shaanxi, 710049, China) Institute of Turbomachinery School of Energy & Power Engineering Xi’an Jiaotong University Xi’an China

This paper presents an aerodynamic optimum design method for transonic turbine cascades based on the Genetic Algorithms coupled to the inviscid flow Euler solver and the boundary-layer *** Genetic Algorithms control the evolution of a population of cascades towards an optimum *** fitness value of each string is evaluated using the flow solver. The design procedur6 has been developed and the behavior of the genetic algorithms has been tested. The objective functions of the design examples are the minimum mean-square deviation between the aimed pressure and computed pressure and the minimum amount of user expertise.

关键词： genetic algorithms transonic turbine cascades optimum design

A k-ε Turbulence Model Considering Compressibility in Three-Dimensional Transonic Turbulent Flow Calculation

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Journal of Thermal Science 2000年第2期9卷 97-102页

作者： Guojun LI zhenping feng Moujin ZhANG Liang LI (School of Energy & Power Engineering, xi’an jiaotong university, xi’an 710049, China) School of Energy & Power Engineering Xi’an Jiaotong University Xi’an China

Based on the standard k-ε turbulence model, a new compressible k-ε model considering the pressure expansion influence due to the compressibility of fluid is developed and applied to the simulation of 3D transonic turbulent flows in a nozzle and a cascade. The Reynolds avenged N-S equations in generalized curvilinear coordinates are solved with implementation of the new model. The high resolution TVD scheme is used to discretize the convective terms. The numerical results show that the compressible k-ε model behaves well in the simulation of transonic internal turbulent flows.

关键词： k-ε turbulence model 3D transonic flows TVD scheme numerical simulation.

Effects of Variable Jet Nozzle Angles on Cross-Flow Suppression and Heat Transfer Enhancement of Swirl Chamber

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Journal of Thermal Science 2022年第1期31卷 214-223页

作者： xiAO Kun HE Juan feng zhenping Institute of Turbomachinery School of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an 710049China

This paper investigated the effects of variable jetting nozzle angles on the cross-flow suppression and heat transfer enhancement of swirl cooling in gas turbine leading edge. The swirl chamber with vertical jet nozzles was set as the baseline, and its flow fields and heat transfer characteristics were analyzed by 3D steady state Reynolds-averaged numerical methods to reveal the mechanism of cross-flow weakening the downstream jets and heat transfer. On this basis, the flow structure on different cross sections and heat transfer characteristics of swirl chamber with variable jetting nozzle angels were compared with the baseline swirl chamber. The results indicated that for the baseline swirl chamber the circumferential velocity gradually decreased and the axial velocity gradually increased, and the cross-flow gradually formed. The cross-flow deflected the downstream jets and drawn them to the center of the chamber, thus weakening the heat transfer. For swirl chamber with variable jetting nozzle angles, the air axial velocity is axial upstream, opposite to the mainstream, so that the impact effects of cross-flow on the jets were reduced, and the heat transfer was enhanced. Furthermore, with the increase of axial velocity along the swirl chamber, the jetting nozzle angle also gradually increased, as well as the effect of cross-flow suppression, which formed a relative balance. For all swirl chambers with variable jet nozzle angles, the thermal performance factors were all larger than 1, which indicated the heat transfer was enhanced with less friction increment.

关键词： swirl cooling cross-flow heat transfer enhancement variable jet nozzle angle

Particle deposition patterns on high-pressure turbine vanes with aggressive inlet swirl

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Chinese Journal of Aeronautics 2022年第3期35卷 75-89页

作者： xing YANG Zihan HAO zhenping feng Shaanxi Engineering Laboratory of Turbomachinery and Power Equipment Institute of TurbomachinerySchool of Energy and Power EngineeringXi’an Jiaotong UniversityXi’an 710049China

Characteristics of particle migration and deposition were numerically investigated in presence of aggressive swirl at the turbine *** isolated effects of the inlet swirl were considered in detail by shifting the circumferential position of the swirl and by implementing positive and negative swirling *** were released from the turbine inlet and the resulting deposition on the vanes was determined by using the critical velocity model in a range of particle diameters from 1 to 25 *** show that the particles are more likely to move outwards to the boundary walls of the passage by the action of the swirling ***,this could be relieved by increasing the particle *** imbalance problem of the deposition is found between the adjacent vanes,which could introduce additional inlet non-uniformities towards the downstream rotor and thus accelerate performance degradation of the turbine ***,the negative swirl case has higher overall capture efficiency within the entire turbine than the positive swirl case for larger particles,and when the inlet swirl is shifted to the mid-passage of the turbine,more deposits could be produced in comparison with the case in which the swirl aims at the vane leading edge.

关键词： Combustor-turbine interaction Gas turbine Inlet swirl Numerical simulation Particle deposition

Tumor Classification of Gene Expression Data by Fuzzy Hybrid Twin SVM

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Chinese Journal of Electronics 2022年第1期31卷 99-106页

作者： DUAN Hua feng tong LIU Songning ZHANG Yulin SU Jionglong College of Mathematics and Systems Science Shandong University of Science and Technology School of AI and Advanced Computing XJTLU Entrepreneur College (Taicang) Xi'an Jiaotong-Liverpool University

A new classification model, the fuzzy hybrid twin support vector machine(TWSVM), namely FHTWSVM, is proposed by combining the fuzzy TWSVM and the hypersphere support vector machine(SVM).The hypersphere SVM is utilized for generating the hyperspheres for the positive and negative class with the smallest possible radius, so that the hyperspheres can contain as many samples as possible. The samples which the hyperspheres cover form a new sample set. Furthermore a distance-based fuzzy function is utilized to calculate the fuzzy factors for the samples. Finally FHTWSVM is used to train all samples with the parameters optimized by grid search. This method can maximize intra-class clustering for noise removal and reduce the influence of *** demonstrate the superiority of the performance of FHTWSVM over other classifiers, e.g., KNN, RF,Bayesian, TWSVM, Ada Boost and XGBoost, a series of experiments is conducted using eight gene expression datasets. The evaluation results show that the proposed approach can improve the classification performance as well as reduce prediction errors for the datasets.

关键词： biology computing support vector machines grid search fuzzy TWSVM hypersphere support vector machine hypersphere SVM intra-class clustering pattern classification fuzzy hybrid twin SVM FHTWSVM tumor classification tumours fuzzy hybrid twin support vector machine learning (artificial intelligence) distance-based fuzzy function fuzzy set theory pattern clustering search problems gene expression data

Abrasive Wear Map of Polymer Tapes in Sand Dust Environment

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Journal of China university of Mining and Technology 2006年第2期16卷 128-131页

作者： WU tong-hai DIAO Dong-feng Key Laboratory of Education Ministry for Modern Design and Rotor-Bearing System Xi＇ an Jiaotong University Xi＇an shaanxi 710049 China

To make clear the wear conditions of ATM (Automatic Teller Machine) tribosystem when servicing in Chi- nese sand dust environment, abrasive wear of two kinds of polymer tapes specified for ATM, PI (Polyimide) and PEN (Polyethylene-2, 6-naphthalenedicarboxylate), was investigated in simulated sand dust environment with ATM tape-scraper tribosystem under various conditions of loads and sliding distances. The surface profiles of worn tape were measured with a surface profiler in order to calculating the wear cross-section areas and the wear volumes. The specific wear rates of polymer tapes were calculated under load conditions of 0.6, 1 and 1.5 N, and wear mechanisms were in- vestigated with optical topography photos. As main results, the specific wear rates show stage variations in the wear process and the wear resistance of polymer tape shows good relationship with the mechanical deformation factors. In consideration of the service life, four wear models are generalized according to the magnitude of specific wear rates, which include no wear, mild wear, normal wear and severe wear model and the corresponding wear mechanisms for the four wear models are discussed with typical worn topographies. Based on the wear models and corresponding wear mechanisms, the abrasive wear maps of two polymer tapes servicing in sand dust environments are concluded for its industrial applications.

关键词： abrasive wear polymer wear map sand dust environment