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Investigation on Multi-objective Performance Optimization Algorithm Application of Fan Based on Response Surface Method and Entropy Method

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Journal of Thermal science 2017年第6期26卷 533-539页

作者： ZHANG Li WU Kexin LIU Yang Department of Application & Engineering Zhejiang Economic & Trade Polytechnical University Key Laboratory of Fluid Transmission technology of zhejiang Province Zhejiang Sci-Tech University

A multi-objective performance optimization method is proposed, and the problem that single structural parame- ters of small fan balance the optimization between the static characteristics and the aerodynamic noise is solved. In this method, three structural parameters are selected as the optimization variables. Besides, the static pressure efficiency and the aerodynamic noise of the fan are regarded as the multi-objective performance. Furthermore, the response surface method and the entropy method are used to establish the optimization function between the op- timization variables and the multi-objective performances. Finally, the optimized model is found when the opti- mization function reaches its maximttm value. Experimental data shows that the optimized model not only en- hances the static characteristics of the fan but also obviously reduces the noise. The results of the study will provide some reference for the optimization of multi-objective performance of other types of rotating machinery.

关键词： small fan response surface method entropy method multi-objective optimization

Numerical study of gas-solid two-phase flow and erosion in a cavity with a slope

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Particuology 2022年第3期20卷 25-35页

作者： Zhe Lin Xiwang Sun Yi Li Zuchao Zhu Key Laboratory of Fluid Transmission technology of zhejiang Province Zhejiang Sci-Tech UniversityHangzhou 310018China National Provincial Joint Engineering Laboratory for Fluid Transmission System technology Zhejiang Sci-Tech UniversityHangzhou 310018China

Gate valve is mainly used to turn on or turn off the pipeline in pneumatic *** the gate valve is fully open,the particles are easy to collide with the cavity rear wall and enter into the cavity,resulting in particles’accumulation in the *** particles in cavity will accumulate between the cavity bottom and the flashboard bottom wall and prevent the gate from turning off ***,the particles’collision with cavity rear wall will cause serious *** the particles’accumulation and erosion will cause the poor sealing of the gate valve,further resulting in the leakage of the pipeline *** reduce the particles’accumulation in cavity and erosion on cavity when the gate valve is fully open,we simplify the gate valve into a cavity structure and study *** find that adding a slope upstream the cavity can effectively reduce the particles’accumulation in the cavity and the erosion on the cavity rear *** this work,Eulerian-Lagrangian method in commercial code(FLUENT)was used to study the gas-solid two-phase flow and erosion characteristics of a cavity with a *** particle distribution shows that the particles with Stokes number St=1.3 and St=13 cannot enter the cavity due to the slope,but the particles with St=0.13 enter the cavity following the *** St=13,the particles collide with the wall many times in the ideal *** results show that the slope can transfer the erosion on cavity rear wall to the slope and reduce the maximum erosion rate of the wall near the cavity to some degrees.

关键词： Cavity with a slope Gas-solid flow Solid particle erosion Stokes number

Numerical and Experimental Study on Aerodynamic Performance of Small Axial Flow Fan with Splitter Blades

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Journal of Thermal science 2013年第4期22卷 333-339页

作者： Zhu Lifu Jin Yingzi Li Yi Jin Yuzhen Wang Yanping Zhang Li The Province Key Laboratory of Fluid Transmission technology Zhejiang Sci-Tech University

To improve the aerodynamic performance of small axial flow fan, in this paper the design of a small axial flow fan with splitter blades is studied. The RNG k-e turbulence model and SIMPLE algorithm were applied to the steady simulation calculation of the flow field, and its result was used as the initial field of the large eddy simulation to calculate the unsteady pressure field. The FW-H noise model was adopted to predict aerodynamic noise in the six monitoring points. Fast Fourier transform algorithm was applied to process the pressure signal. Experiment of noise testing was done to further investigate the aerodynamic noise of fans. And then the results obtained from the numerical simulation and experiment were described and analyzed. The results show that the static characteristics of small axial fan with splitter blades are similar with the prototype fan, and the static characteristics are improved within a certain range of flux. The power spectral density at the six monitoring points of small axial flow fan with splitter blades have decreased to some extent. The experimental results show sound pressure level of new fan has reduced in most frequency bands by comparing with prototype fan. The research results will provide a proof for parameter optimization and noise prediction of small axial flow fans with high performance.

关键词： small axial flow fan splitter blades noise frequency

Study on Airflow Characteristics in the Semi-Closed Irregular Narrow Flow channel

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Journal of Thermal science 2016年第2期25卷 123-129页

作者： JIN Yuzhen HU Xiaodong ZHU Linhang HU Xudong JIN Yingzi zhejiang Provincial Key Lab of Modern Textile Machinery & technology Zhejiang Sci-Tech University 1201 Chu Kochen Honors College Zhejiang University

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关键词： air-jet loom profiled dents numerical simulation airflow characteristics semi-closed channel

Unsteady Flow Characteristic of Low-Specific-Speed Centrifugal Pump under Different Flow-Rate Conditions

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Journal of Thermal science 2015年第1期24卷 17-23页

作者： CUI Baoling CHEN Desheng XU Wenjing JIN Yingzi ZHU Zuchao The Provincial Key Laboratory of Fluid Transmission technology Zhejiang Sci-Tech University

To investigate the unsteady flow characteristics in centrifugal pump, the flow field in a low-specific-speed centri- fugal pump with complex impeller is numerically simulated under different conditions. The RNG r-e turbulence model and sliding mesh are adopted during the process of computation. The results show that the interaction be- tween impeller and volute results in the unstable flow of the fluid, which causes the uneven distribution of pres- sure fluctuations around the circumference of volute. Besides the main frequency and its multiple frequency of pressure fluctuations in the centrifugal pump, the frequency caused by the long blades of complex impeller also plays a dominant role in the low-frequency areas. Furthermore, there exists biggish fluctuation phenomenon near the tongue. The composition of static pressure fluctuations frequency on the volute wall and blade outlet is similar except that the fluctuation amplitude near the volute wall reduces. In general, the different flow rates mainly have influence on the amplitude of fluctuation frequency in the pump, while have little effect on the frequency compo- sition.

关键词： Centrifugal pump Low-specific-speed Complex impeller Unsteady Numerical simulation

Symmetry Reduction of the(2+1)-Dimensional Modified Dispersive Water-Wave System

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Communications in Theoretical Physics 2015年第8期64卷 127-132页

作者：马正义费金喜杜晓阳 Department of Mathematics Zhejiang Lishui University Department of Mathematics Zhejiang Sci-Tech University Department of Electronics Zhejiang Lishui University

Using the standard truncated Painlev expansion, the residual symmetry of the(2+1)-dimensional modified dispersive water-wave system is localized in the properly prolonged system with the Lie point symmetry vector. Some different transformation invariances are derived by utilizing the obtained symmetries. The symmetries of the system are also derived through the Clarkson-Kruskal direct method, and several types of explicit reduction solutions relate to the trigonometric or the hyperbolic functions are obtained. Finally, some special solitons are depicted from one of the solutions.

关键词： dispersive water-wave system symmetry reduction ex

Path Planning for Intelligent Robots Based on Deep Q-learning With Experience Replay and Heuristic Knowledge

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IEEE/CAA Journal of Automatica Sinica 2020年第4期7卷 1179-1189页

作者： Lan Jiang Hongyun Huang Zuohua Ding the Laboratory of Intelligent Computing and Software Engineering Zhejiang Sci-Tech UniversityHangzhou 310018China the Center of Multi-Media Big Data of Library Zhejiang Sci-Tech UniversityHangzhou 310018China

Path planning and obstacle avoidance are two challenging problems in the study of intelligent robots. In this paper, we develop a new method to alleviate these problems based on deep Q-learning with experience replay and heuristic knowledge. In this method, a neural network has been used to resolve the "curse of dimensionality" issue of the Q-table in reinforcement learning. When a robot is walking in an unknown environment, it collects experience data which is used for training a neural network;such a process is called experience *** knowledge helps the robot avoid blind exploration and provides more effective data for training the neural network. The simulation results show that in comparison with the existing methods, our method can converge to an optimal action strategy with less time and can explore a path in an unknown environment with fewer steps and larger average reward.

关键词： Deep Q-learning(DQL) experience replay(ER) heuristic knowledge(HK) path planning

Fine-Grained Features for Image Captioning

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Computers, Materials & Continua 2023年第6期75卷 4697-4712页

作者： Mengyue Shao Jie Feng Jie Wu Haixiang Zhang Yayu Zheng zhejiang sci-tech university Hangzhou310020China zhejiang university of technology Hangzhou310020China

Image captioning involves two different major modalities(image and sentence)that convert a given image into a language that adheres to visual *** all methods first extract image features to reduce the difficulty of visual semantic embedding and then use the caption model to generate fluent *** Convolutional Neural Network(CNN)is often used to extract image features in image captioning,and the use of object detection networks to extract region features has achieved great ***,the region features retrieved by this method are object-level and do not pay attention to fine-grained details because of the detection model’s *** offer an approach to address this issue that more properly generates captions by fusing fine-grained features and region ***,we extract fine-grained features using a panoramic segmentation ***,we suggest two fusion methods and contrast their fusion *** X-linear Attention Network(X-LAN)serves as the foundation for both fusion *** to experimental findings on the COCO dataset,the two-branch fusion approach is *** is important to note that on the COCO Karpathy test split,CIDEr is increased up to 134.3%in comparison to the baseline,highlighting the potency and viability of our method.

关键词： Image captioning region features fine-grained features fusion

An apodized cubic phase mask used in a wavefront coding system to extend the depth of field

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Chinese Physics B 2022年第5期31卷 422-428页

作者： Lina Zhu Fei Li Zeyu Huang Tingyu Zhao Department of Physics Key Laboratory of Optical Field Manipulation of Zhejiang ProvinceZhejiang Sci-Tech UniversityHangzhou 310018China

The point spread function(PSF)caused by a wavefront coding system with a cubic phase mask has big side-lobes which leads to bad image *** paper proposes a novel apodized cubic phase mask to suppress the side-lobes of the *** annealing algorithm is used to optimize the cubic and the truncation parameter of the phase *** system with the novel phase mask has better performance in the modulation transfer function(MTF)especially in low-and-medium spatial frequency *** simulation results show that the restored images with the novel phase mask are superior to the one with the classic cubic phase mask in contrast and ringing *** experimental results show that the side-lobes of the PSF are suppressed by using the apodized cubic phase mask.

关键词： apodized cubic phase mask wavefront coding depth of field image restoration