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现代食品 2024年第6期30卷 135-137页

作者：金英姿新疆轻工职业技术学院新疆乌鲁木齐830000

在酸奶生产过程中,发酵时间、温度和原料配比,对酸奶品质、口感、质地和保质期有明显影响。因此,本文分析了酸奶加工工艺以及一系列质量控制措施,以确保酸奶品质。

关键词：酸奶加工工艺优化质量控制

Effect of Tip Flange on Tip Leakage Flow of Small Axial Flow Fans

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Journal of Thermal Science 2014年第1期23卷 45-52页

作者： ZHANG Li jin yingzi jin Yuzhen The Province Sky Lab of Fluid Transmission Technology Zhejiang Sci-Tech University

Aerodynamic performance of an axial flow fan is closely related to its tip clearance leakage flow. In this paper, the hot-wire anemometer is used to measure the three dimensional mean velocity near the blade tips. Moreover, the filtered N-S equations with finite volume method and RNG k-ε turbulence model are adopted to carry out the steady simulation calculation of several fans that differ only in tip flange shape and number. The large eddy simulation and the FW-H noise models are adopted to carry out the unsteady numerical calculation and aerodynamic noise prediction. The results of simulation calculation agree roughly with that of tests, which proves the numerical calculation method is *** effects of tip flange shapes and numbers on the blade tip vortex structure and the characteristics are analyzed. The results show that tip flange of the fan has a certain influence on the characteristics of the fan. The maximum efficiencies for the fans with tip flanges are shifted towards partial flow with respect to the design point of the datum fan. Furthermore, the noise characteristics for the fans with tip flanges have become more deteriorated than that for the datum fan. Tip flange contributes to forming tip vortex shedding and the effect of the half-cylinder tip flange on tip vortex shedding is obvious. There is a distinct relationship between the characteristics of the fan and tip vortex *** research results provide the profitable reference for the internal flow mechanism of the performance optimization of small axial flow fans.

关键词：泄漏流动轴流风机法兰空气动力性能数值计算方法轴流风扇噪声特性端部形状

Effects of rotor structure on performance of small size axial flow fans

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Journal of Thermal Science 2011年第3期20卷 205-210页

作者： Pin Liu yingzi jin Yanping Wang Laboratory of Fluid Transmission and Application Zhejiang Sci-Tech University Hangzhou 310018 China

Small size axial flow fans are used as a cooling component for computers,electronic equipment and other electronic *** the increasing power of electrical equipment,the demand for lower noise and higher ventilation of cooling fan is also *** methods of improving ventilation by raising the fan's rotation speed causes a decrease in efficiency and an increase in *** this paper,different structures of fans were simulated,and as a result,the counter-rotating fan can achieve higher pressure,efficiency and facilitate ventilation in a smaller ***,some other conclusions are as follows:(1) Higher pressure rise can be obtained by a counter-rotating fan than by the two-stage rotor fan in the same axial ***,the counter-rotating fan has a broader work scope.(2) The main noise type of the counter-rotating fan is rotating noise;the small peak pulse caused by vortex noise mainly due to the eddy current produced by small eddies.(3) When the distance of counter-rotating fans is smaller than 2 times the chord,the greater distance the greater total pressure of the circum-averages and along the axial direction,the total pressure begin to decline until the distance is three times the chord,so there is an optimal distance between *** simulation results are of important significance to the quantitative analysis and optimization design of the counter-rotating fan.

关键词：转子结构风机性能轴流风机小尺寸散热风扇涡流噪声最佳距离压力上升

Research on the Response Characteristics of Solenoid Valve of the Air-jet Loom by Simulation

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Journal of Thermal Science 2013年第6期22卷 606-612页

作者： jin Yuzhen DENG Ruoyu jin yingzi HU Xudong Faculty of Mechanical Engineering & Automation Zhejiang Sci-Tech University

Solenoid valve is one of the executive parts of weft insertion control system. According to the response characteristics of the solenoid valve, an improved design becomes a necessity. Firstly, the numerical model was established after analyzing the solenoid valve during its start-up and shut-down. Comparing the simulation data with the practical data, it is verified that the numerical simulation model has a high feasibility. Secondly, excitation voltage and spring pre-compression were adjusted respectively, and the response rules after adjusting were investigated. The research of the study shows: the response time tends to be inverse proportional to the excitation voltage during start-up, and it becomes a constant value with the increase of the excitation voltage; the response time is proportional to the spring pre-compression when the solenoid valve starts up, it is inverse proportional to spring pre-compression when the solenoid valve shuts down. And the total response time is a constant value with the increase of the spring pre-compression. Therefore, the value of the excitation voltage and the spring pre-compression should be selected when the curve is becoming flatten. The results of the research can provide the reference to the further development of the solenoid valve.

关键词：数值模拟模型电磁阀响应特性喷气织机激励电压地球化学特征反应时间预压缩

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

The air-jet loom is widely used in the textile industry. The interaction mechanism of airflow and yarn is not clear in such a narrow flow channel, the gas consumption is relatively large, the yarn motion is unstable and the weft insertion is often interrupted during the operation. In order to study the characteristics of the semi-closed flow field in profiled dents, the momentum conservation equation is modified and the model parameters and boundary conditions are set. Compared with the different r, the ratio of profiled dent's thickness and gap, the results show that the smaller the r is, the smaller the velocity fluctuations of the airflow is. When the angle of profiled dents ? is close to zero, the diffusion of the airflow will be less. The experiment is also conducted to verify the result of the simulation with a high-speed camera and pressure sensor in profiled dents. The airflow characteristics in the semi-closed irregular narrow flow channel in the paper would provide the theoretical basis for optimizing the weft insertion process of the air-jet loom.

关键词：气流特性半封闭流道

Influence of Blade Outlet Angle on Performance of Low-specific-speed Centrifugal Pump

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Journal of Thermal Science 2013年第2期22卷 117-122页

作者： Cui Baoling Wang Canfei Zhu Zuchao jin yingzi The Province Key Laboratory of Fluid Transmission Technology Zhejiang Sci-Tech University

In order to analyze the influence of blade outlet angle on inner flow field and performance of low-specific-speed centrifugal pump, the flow field in the pump with different blade outlet angles 32.5°and 39° was numerically calculated. The external performance experiment was also carried out on the pump. Based on SIMPLEC algorithm, time-average N-S equation and the rectified k-ε turbulent model were adopted during the process of computation. The distributions of velocity and pressure in pumps with different blade outlet angles were obtained by calculation. The numerical results show that backflow areas exist in the two impellers, while the inner flow has a little improvement in the impeller with larger blade outlet angle. Blade outlet angle has a certain influence on the static pressure near the long-blade leading edge and tongue, but it has little influence on the distribution of static pressure in the passages of impeller. The experiment results show that the low-specific-speed centrifugal pump with larger blade outlet angle has better hydraulic performance.

关键词：叶轮叶片低比转速出口角泵性能离心泵 SIMPLEC算法数值计算内流场

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-ε 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：轴流风机分流叶片测试实验气动性能数值模拟噪声预测模型快速傅立叶变换算法 SIMPLE算法

Numerical Analysis of Chevron Nozzle Effects on Performance of the Supersonic Ejector-Diffuser System

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Journal of Thermal Science 2013年第5期22卷 459-466页

作者： Fanshi Kong yingzi jin Toshiaki Setoguchi Heuy Dong Kim College of Mechanical Engineering & Automation Zhejiang Sci-Tech University School of Mechanical Engineering Andong National University Department of Mechanical Engineering Saga University

The supersonic nozzle is the most important device of an ejector-diffuser *** best operation condition and optimal structure of supersonic nozzle are hardly known due to the complicated turbulent mixing,compressibility effects and even flow unsteadiness which are generated around the nozzle *** the present study,the primary stream nozzle was redesigned using convergent nozzle to activate the shear actions between the primary and secondary streams,by means of longitudinal vortices generated between the Chevron *** same geometrical model of ejector-diffuser system was created to validate the results of experimental *** operation characteristics of the ejector system were compared between Chevron nozzle and conventional convergent nozzle for the primary stream.A CFD method has been applied to simulate the supersonic flows and shock waves inside the *** is observed that the flow structure and shock system were changed and primary numerical analysis results show that the Chevron nozzle achieve a positive effect on the supersonic ejector-diffuser system *** ejector with Chevron nozzle can entrain more secondary stream with less primary stream mass flow rate.

关键词：超音速喷嘴喷嘴装置曝气系统数值分析性能弹射最佳运行条件收敛喷管

Three-dimensional Numerical Simulation of the Movement of the Flexible Body under Different Constraints

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Journal of Thermal Science 2014年第6期23卷 593-599页

作者： jin Yuzhen LI Jun ZHU Linhang DU Jiayou jin yingzi LIN Peifeng Zhejiang Provincial Key Lab of Modern Textile Machinery & Technology Zhejiang Sci-Tech University 1201 Chu Kochen Honors College Zhejiang University

For the large deformation of the flexible body may cause the fluid grid distortion,which will make the numerical calculation tedious,even to end,the numerical simulation of the flexible body coupling with the fluid is always a tough *** this paper,the flexible body is under two kinds of constrained conditions and the ratio of length-diameter is 1:*** Reynolds number of the airflow is 513,belonging to the area of low Reynolds *** control equations of the coupling of flexible body with airflow are built and the adaptive grid control method is adopted to conduct the three-dimensional numerical simulation of the movement of the flexible *** numerical results show that it is possible to simulate the characteristics of the flexible body's movement in the low Reynolds number airflow when the appropriate control equations are modeled and suitable equation-solving method is *** flexible body would turn over forward along the airflow's diffusion direction,while constrained flexible body in the flow field will make periodic rotation motion along the axis of the flexible body,and the bending deformation is more obvious than that of unconstrained flexible *** preliminary three-dimensional numerical simulation can provide references for further research on the characteristics of the yam movement in high Reynolds number airflow.

关键词：三维数值模拟旋转运动柔性体低雷诺数控制方程数值计算网格控制计算结果

Research on Performance of Centrifugal Pump with Different-type Open Impeller

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Journal of Thermal Science 2013年第6期22卷 586-591页

作者： CUI Baoling CHEN Desheng WANG Canfei ZHU Zuchao jin yingzi jin Yuzhen The Province Key Laboratory of Fluid Transmission Technology Zhejiang Sci-Tech University

To investigate the influence of impeller type on the performance and inner flow of centrifugal pump, the numerical simulation and experimental research were carried out on the same centrifugal pump with straight-blade and curved-blade open impeller. Based on SIMPLEC algorithm, time-averaged N-S equation and the standard k-εturbulence model, the numerical results are obtained. The pressure distribution in the different type impellers is uniform, while the low pressure area in straight-blade inlet is larger. The vortexes in the passage of impeller exist in both cases. Relative to curved-blade impeller, there are larger vortexes in most of the flow passages except the passage near the tongue in straight-blade impeller. Also some small backflow regions are found at the blade inlet of two impellers. The characteristic curves achieved by numerical simulation basically agree with those by experiment, and straight-blade open impeller centrifugal pump has a better hydraulic performance.

关键词：开式叶轮水力性能离心泵类型 SIMPLEC算法流体通道数值模拟直叶片