International Journal of Rotating Machinery最新文献_第2页

Effects of Diffusion Film Hole Exit Area on the Film Cooling Effectiveness 扩散膜出孔面积对膜冷却效果的影响

IF 0.9

International Journal of Rotating Machinery Pub Date : 2022-09-17 DOI: 10.1155/2022/5994933

Fan Yang, M. Taslim

{"title":"Effects of Diffusion Film Hole Exit Area on the Film Cooling Effectiveness","authors":"Fan Yang, M. Taslim","doi":"10.1155/2022/5994933","DOIUrl":"https://doi.org/10.1155/2022/5994933","url":null,"abstract":"One popular method for the protection of gas turbines’ hot sections from high-temperature combustor gases is film cooling. Substantial amounts of research have been conducted to accomplish this task with the minimum cooling flow, maximum surface coverage, and minimal aerodynamic inefficiencies or structural penalties. In this study, a combined experimental and numerical investigation was conducted on three selected film-cooling hole geometries. These geometries were designed with the same initial metering (feed) section, a cylindrical hole of 30° inclination angle, followed by three different forward expansion section geometries. The expansion sections had a 7° laid-back angle and a 17° expansion angle in each lateral direction. However, different interior corner radii were used to blend the metering hole to the exit area, creating three different expansion geometries with almost the same exit areas. In practice, this variation in expansion geometry could represent manufacturing faults or tolerances in laser drilling of the film holes. This study shows that the variations in film-cooling effectiveness are not significant even though the expansion geometries are significantly different. The Pressure Sensitive Paint (PSP) technique was used to obtain the detailed distribution of film-cooling effectiveness on the surface area downstream of these film holes. Adiabatic film cooling effectiveness was measured at blowing ratios of 0.5, 1.0, and 2.0. CFD models of these film holes were also run, and the results were compared with the test data. The major conclusions of this study were that these proposed new geometries produced higher film effectiveness than the conventional 7°-7°-7° diffusion film holes, for the same exit area, the expansion section geometry of the film holes did not have a significant effect on the film coverage, and the numerical results were in good agreement with the test data.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49427625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Analysis for Hydrodynamic Wedge-Platform Thrust Slider Bearing with Ultralow Surface Separation 超低表面分离楔台滑动轴承的流体动力分析

IF 0.9

International Journal of Rotating Machinery Pub Date : 2022-08-18 DOI: 10.1155/2022/8101357

Chao-Min Wang, Yongbin Zhang

{"title":"Analysis for Hydrodynamic Wedge-Platform Thrust Slider Bearing with Ultralow Surface Separation","authors":"Chao-Min Wang, Yongbin Zhang","doi":"10.1155/2022/8101357","DOIUrl":"https://doi.org/10.1155/2022/8101357","url":null,"abstract":"For the case of ultralow surface separation, in a hydrodynamic wedge-platform thrust slider bearing, the outlet zone and a portion of the inlet zone are in boundary lubrication, while most of the inlet zone is in the multiscale lubrication contributed by both the adsorbed boundary layer and the intermediate continuum fluid film. The present paper first presents the mathematical derivations for the generated pressure and carried load of this bearing based on the governing equation for boundary lubrication and the multiscale flow equation. Then, the full numerical calculation is carried out to verify the analytical derivations. It was found that the mathematical derivations normally have considerable errors when calculating the hydrodynamic pressure distribution in the bearing, owing to introducing the equivalent parameter \u0000 \u0000 \u0000 \u0000 λ\u0000 \u0000 \u0000 bf\u0000 ,\u0000 e\u0000 \u0000 \u0000 \u0000 which is constant in the inlet zone; however they can be used to calculate the carried load of the bearing when the surface separation in the outlet zone is sufficiently high. The study suggests the necessity of the numerical calculation of the hydrodynamic pressure and even the carried load of this bearing. It is also shown that owing to the fluid-bearing surface interaction, the pressure and carried load of this bearing are significantly greater than those calculated from the classical hydrodynamic theory.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44688595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modelling of Hydroabrasive Erosion in Pelton Turbine Injector 水轮机喷油器水力磨料侵蚀模型研究

IF 0.9

International Journal of Rotating Machinery Pub Date : 2022-07-31 DOI: 10.1155/2022/9772362

T. Bajracharya, R. Shrestha, Anil Sapkota, Ashesh Babu Timilsina

{"title":"Modelling of Hydroabrasive Erosion in Pelton Turbine Injector","authors":"T. Bajracharya, R. Shrestha, Anil Sapkota, Ashesh Babu Timilsina","doi":"10.1155/2022/9772362","DOIUrl":"https://doi.org/10.1155/2022/9772362","url":null,"abstract":"Sand particle-led erosion in the turbine parts of hydropower projects (excluding storage type projects) based on Himalaya-originated Rivers is one of the key operational challenges for concerned hydropower stations. Researchers have made multiple attempts to understand the nature of erosion and its combating technique by using numerical and experimental modelling techniques. This study relates to numerical and experimental modelling of sand particle-led erosion in the injector of the most preferred high head turbine, i.e., the Pelton turbine, followed by a comparative analysis of both techniques. This article attempts to compare erosion qualitatively and quantitatively, thus adding to the current state of the art of turbine erosion modelling. The results direct that the erosion-prone area is the needle seat in the nozzle and the region between the needle tip and nozzle exit in the needle, similar to findings reported by authors performing field setting research. The innovative aspect of the study is that by mapping the shape of the initial and eroded needle, mass lost in the erosion-prone area (as indicated by numerical erosion modelling) is calculated and compared against numerical modelling results. With the Oka erosion model employed for numerical modelling, the error in computation is about 31%. The nature of erosion in a partially open injector reveals that erosion in the needle increases with the nozzle’s partial opening. Nozzle erosion spreads away from the needle seat to the whole nozzle body. As commonly understood, the erosion of turbine parts gives rise to mechanical vibrations (especially in rotating parts) and energy loss. Numerical modelling results of injector erosion’s effect on jet energy are also presented. With uniformly spread erosion of 0.5 mm in both the needle and nozzle, loss in jet energy is 5.63%.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48437313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Dust Removal Mechanism of the Vibrating String Filter with Charged Water Mist 带电细水雾振弦过滤器的除尘机理

IF 0.9

International Journal of Rotating Machinery Pub Date : 2022-06-20 DOI: 10.1155/2022/5713983

Zuyu Chen, Ziyi Zhou, Jicheng Peng

{"title":"Dust Removal Mechanism of the Vibrating String Filter with Charged Water Mist","authors":"Zuyu Chen, Ziyi Zhou, Jicheng Peng","doi":"10.1155/2022/5713983","DOIUrl":"https://doi.org/10.1155/2022/5713983","url":null,"abstract":"The traditional dust removal technology is difficult to meet the strict requirements of environmental protection, so it is of practical significance and research value to study how to purify fine dust in workshop. Fine dust can be suspended in the atmosphere, while reducing the air quality. Excessive inhalation of dust may result in disease. So it should be paid close attention to dust control. The water mist charging process has experienced three stages: induction charge, corona charge transition, and corona charge. When the discharge distance is 80 mm, the charge-mass ratio of droplet and the current of water mist are most affected by corona voltage. The significant impact analysis of orthogonal experiment is studied. The result of the orthogonal experiment is analyzed by the variance method. It is noted that the inlet wind speed has the highest influence, and the discharge distance has a least influence on the dust removal efficiency. The discharge distance is 80 mm, and the voltage working band is suitable for the normal voltage regulation of the electrostatic precipitator. The condensation efficiency of charged droplets on dust is beneficial to reduce the negative effect of excessive wind speed on wet vibrating string grid and to improve the effective handling volume of dust collector. The charge-mass ratio of water mist is improved effectively, and the dust removal efficiency is increased in the vibrating string filter with charged water mist. Theoretical analysis and experimental studies showed that the vibrating string filter with charged water mist is as a new composite efficient dust removal technology that can effectively deal with the purification of fine dust particles in the gas stream, especially in respiratory dust removal.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49072390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Experimental and Numerical Studies of the Film Cooling Effectiveness Downstream of a Curved Diffusion Film Cooling Hole 弯曲扩散膜冷却孔下游气膜冷却效果的实验与数值研究

IF 0.9

International Journal of Rotating Machinery Pub Date : 2022-05-09 DOI: 10.1155/2022/9913692

Fan Yang, M. Taslim

{"title":"Experimental and Numerical Studies of the Film Cooling Effectiveness Downstream of a Curved Diffusion Film Cooling Hole","authors":"Fan Yang, M. Taslim","doi":"10.1155/2022/9913692","DOIUrl":"https://doi.org/10.1155/2022/9913692","url":null,"abstract":"Film cooling technology is a commonly used method for thermal protection of gas turbines’ hot sections. A new, shaped, film cooling hole is proposed in this study. The geometry is made of a straight-through cylindrical feed hole at an inclination angle of 30° followed by an expansion section. The expansion section is created by the rotation of the same circular hole on the inclination plane about an axis normal to that plane which passes through the center of the feed hole exit area. This shape was designed to decrease the deteriorating effects of kidney vortices by proper distribution of the coolant flow emerging from the hole exit area. Cases with four rotation angles (7°, 14°, 17.5°, and 21°) were studied both experimentally and numerically and for the blowing ratios of 0.5, 1, and 2.0. For comparisons, the commonly used 7°-7°-7° diffusion hole geometry was also tested under otherwise identical conditions. For data collection, the pressure-sensitive paint (PSP) technique was used to measure the film cooling effectiveness. Streamwise- and spanwise-averaged film effectiveness results were obtained to compare the performance of different geometries. The main conclusions were that the case of 21° rotation angle produced the highest film effectiveness and outperformed the 7°-7°-7° diffusion hole geometry.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-05-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46941495","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Type Synthesis Based on Modular Combination with Virtual Rotation Center and Application 基于虚旋转中心模块化组合的类型综合及其应用

IF 0.9

International Journal of Rotating Machinery Pub Date : 2022-03-03 DOI: 10.1155/2022/5216327

Xinning Li, Qishuo Zhang, Zongsu Zhang, Xianhai Yang, Hu Wu, Yongbo Li, Hailong Qu

{"title":"Type Synthesis Based on Modular Combination with Virtual Rotation Center and Application","authors":"Xinning Li, Qishuo Zhang, Zongsu Zhang, Xianhai Yang, Hu Wu, Yongbo Li, Hailong Qu","doi":"10.1155/2022/5216327","DOIUrl":"https://doi.org/10.1155/2022/5216327","url":null,"abstract":"Type synthesis of mechanical structure is of great significance to the realization of mechanism target function, systematization, and stability of mechanical device. The type synthesis method of multilinkage robot has been given high demands with increasing number of degrees of freedom and high flexibility in special occasions. In order to improve the workspace and flexibility of mechanism, this paper studies the existing type synthesis theory and proposes a type synthesis method of modular combination with virtual rotation centers. Firstly, modular units are built. Secondly, modular units are expanded according to the needed paths. In the end, the expanded modular units are combined to form the kinematic linkages. Based on the proposed method, the configuration design of the aerial working platform and the self-adaptive levelling platform is completed. The stabilities of two platforms are checked by modal analysis. The prototype products are manufactured, respectively, for further verifying validity of the method. The designed aerial working platform with virtual rotation centers can achieve 360° rotating large workspace, more compact mechanical structure, and short arrival time at the same height than the common scissor-type and mast-type aerial working platforms. The designed adaptive levelling platform is tested that ensures the levelling of the upper surface at different inclinations. The method can provide new idea for the mechanism configuration and expand the application scope of new mechanisms.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2022-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44205087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effect of Pole Number on Generator End Winding Electromagnetic Force and Mechanical Response before and after RISC RISC前后极数对发电机端部绕组电磁力和机械响应的影响

IF 0.9

International Journal of Rotating Machinery Pub Date : 2021-12-23 DOI: 10.1155/2021/4375415

Hong-Chun Jiang, Yu‐Ling He, Gui-ji Tang

引用次数: 0

Experimental Research on the Similarity of Rime Icing on a Cylinder Rotating around Its Horizontal Axis 绕水平轴旋转圆柱体上雾霾结冰相似性的实验研究

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International Journal of Rotating Machinery Pub Date : 2021-11-08 DOI: 10.1155/2021/9986733

Lei Shi, Yan Li, Wenfeng Guo, Ce Sun

{"title":"Experimental Research on the Similarity of Rime Icing on a Cylinder Rotating around Its Horizontal Axis","authors":"Lei Shi, Yan Li, Wenfeng Guo, Ce Sun","doi":"10.1155/2021/9986733","DOIUrl":"https://doi.org/10.1155/2021/9986733","url":null,"abstract":"Ice accumulation on the blade of a wind turbine surface seriously threatens the operational safety of the turbine; therefore, the research on this problem is very important. In this paper, a new similarity criterion of icing shape for a rotational model was proposed based on the similarity criterion for translational motion models in the aviation field, and experimental studies on the similarity of the rotational model icing were carried out. To validate the similarity criterion, icing wind tunnel tests were carried out with aluminum cylinders with diameters of 40 mm and 20 mm. Key parameters for the experiment, such as wind speed, temperature, liquid water content, medium volume diameter, and test time, were selected based on the criterion. All the icing tests were carried out in a new self-designed icing wind tunnel test system based on natural low-temperature conditions. The icing shapes observed in the tests were confirmed after many repetitions. To quantitatively analyze the similarity between different sizes of ice shapes, a dimensionless method for evaluating the similarity of ice shapes of different sizes was defined based on the typical characteristics of ice shapes. The research results show that the similarity score between two sizes of ice shapes under different test conditions is 81%~90%. The accuracy and applicability of the icing shape similarity criterion were thus validated. The research results in this paper lay a theoretical and experimental foundation for exploring the icing shape similarity of a rotating model.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49639202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Analysis of the Rotor Magnetomotive Force of Built-In Radial Permanent Magnet Generator for Vehicle 车载内置径向永磁发电机转子磁动势分析

IF 0.9

International Journal of Rotating Machinery Pub Date : 2021-11-08 DOI: 10.1155/2021/5319615

Huihui Geng, Xueyi Zhang, Tao Si, Lanian Tong, Qingzhi Ma, Mingjun Xu

{"title":"Analysis of the Rotor Magnetomotive Force of Built-In Radial Permanent Magnet Generator for Vehicle","authors":"Huihui Geng, Xueyi Zhang, Tao Si, Lanian Tong, Qingzhi Ma, Mingjun Xu","doi":"10.1155/2021/5319615","DOIUrl":"https://doi.org/10.1155/2021/5319615","url":null,"abstract":"Permanent magnet generator (PMG) for vehicles has attracted more and more attention because of its high efficiency, high power density, and high reliability. However, the weak main air-gap magnetic field can affect the output performance and the normal use of electrical equipment. Aiming at the problem, this paper took the rotor magnetomotive force (MMF), the direct influencing parameter of the main air-gap magnetic field, as the research object, deduced the analytical expression of rotor MMF of the built-in radial PMG in detail, and analyzed its main influencing factors in analytical expression, including the permanent magnet steel (PMS) material, the thickness of PMS in magnetizing direction, the vertical length of the inner side of PMS, and the effective calculation length of PMS. Based on this, the rotor parameters were optimized to obtain the best values. After that, the finite element simulation and prototype test of the optimized generator were carried out. The comparative analysis results showed that the optimized rotor parameters could effectively improve the rotor MMF and optimize the output performance of the generator.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43853014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Structures Dynamic Property Analysis of Elastic Composite Cylindrical Rolling Element 弹性复合圆柱滚动体结构动力性能分析

IF 0.9

International Journal of Rotating Machinery Pub Date : 2021-10-18 DOI: 10.1155/2021/4244659

Yao Qishui, Chen Qianxu, Yuan Jianghong, Yang Wen

{"title":"Structures Dynamic Property Analysis of Elastic Composite Cylindrical Rolling Element","authors":"Yao Qishui, Chen Qianxu, Yuan Jianghong, Yang Wen","doi":"10.1155/2021/4244659","DOIUrl":"https://doi.org/10.1155/2021/4244659","url":null,"abstract":"Elastic composite cylindrical roller bearing is a novel type of roller bearing whose rolling element is designed by innovating the rolling element structure of cylindrical roller bearings. For the purpose of investigating the dynamic properties of the rolling elements with different structural parameters and solving the modes of elastic composite cylindrical rolling element with different filling degrees, first, this study compares elastic composite cylindrical rolling element to solid cylindrical rolling element, in terms of natural frequency and vibration mode. Next, the integration time step is determined, based on the natural frequency of the vibration in the Y direction, the response of various rolling element, under impact loads, is solved. Furthermore, the laws of the energy changes and nodal displacement variations of rolling element are explored, at different filling degrees. Finally, adopting the decay method, the damping ratio of elastic composite cylindrical rolling element, under different structural parameters and external loads, is calculated. According to the results, with the increase of filling degree, the natural frequencies of various orders of elastic composite cylindrical rolling element gradually declined. The damping ratio of rolling elements decreased, as the filling degree increased, while it could be changed by adjusting the structural dimensions of rolling elements. The analysis results of this study provide some theoretical reference for studies on the parameter optimization of rolling element structures, the vibration and noise reduction of elastic composite cylindrical roller bearings.","PeriodicalId":46335,"journal":{"name":"International Journal of Rotating Machinery","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2021-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43417217","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2