Senchun Miao^1,2,*, Hongbiao Zhang¹, Wanglong Tian¹, Yinqiang Li²

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.6, pp. 1021-1036, 2021, DOI:10.32604/fdmp.2021.016925

Abstract To study the unsteady flow and related energy conversion process in the volute of a pump-as-turbine (PAT) device, six different working conditions have been considered. Through numerical calculation, the spatio-temporal variation of static pressure, dynamic pressure, total pressure and turbulent energy dissipation have been determined in each section of the volute. It is concluded that the reduction of the total power of two adjacent sections of the PAT volute is equal to the sum of the power lost by the fluid while moving from one section to the other and the power output from the two adjacent sections. For a… More >

Zhiqi Zhou^*

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.6, pp. 1091-1100, 2021, DOI:10.32604/fdmp.2021.016618

Abstract A relevant way to promote the sustainable development of energy is to use hydropower. Related systems heavily rely on the use of turbines, which require careful analysis and optimization. In the present study a mixed experimental-numerical approach is implemented to investigate the related mixed water flow. In particular, particle image velocimetry (PIV) is initially used to verify the effectiveness of the numerical model. Then numerical results are produced for various conditions. It is shown that an increase in the guide vane opening can reduce the extension of the region where the fluid velocity is 0 at the inlet of the… More >

Dandan Song^1,*, Lianjun Zhou¹, Ziqi Peng², Senhua Luo², Jun Zhu³

Energy Engineering, Vol.118, No.5, pp. 1439-1452, 2021, DOI:10.32604/EE.2021.015011

Abstract The axial flux permanent magnet (AFPM) generator with double-sided internal stator structure is highly suitable for vertical axis wind turbines due to its high power density. The performance of the AFPM generator with double-sided internal stator structure can be improved by the reasonable design of electromagnetic parameters. To further improve the overall performance of the AFPM generator with double-sided internal stator structure, multivariable (coil width ω_c, permanent magnet thickness h, pole arc coefficient α_p and working air gap l_g) and multi-objective (generator efficiency η, total harmonic distortion of the voltage THD and induced electromotive force amplitude EMF) functional relationships are… More >

Wei Zhang^1,2, Qihui Ling^1,2,*, Qiancheng Zhao^1,2, Hushu Wu³

Energy Engineering, Vol.118, No.5, pp. 1515-1535, 2021, DOI:10.32604/EE.2021.014162

Abstract The condition monitoring and fault diagnosis have been identified as the key to achieving higher availabilities of wind turbines. Numerous studies show that the open-circuit fault is a significant contributor to the failures of wind turbine converter. However, the multiple faults combinations and the influence of wind speed changes abruptly, grid voltage sags and noise interference have brought great challenges to fault diagnosis. Accordingly, concerning the open-circuit fault of converters in direct-driven PMSG wind turbine, a diagnostic method for multiple open-circuit faults is proposed in this paper, which is divided into two tasks: The first one is the fault detection… More >

Jiangyong Bao¹, Jianjun He^1,*, Biao Chen², Kaijun Yang¹, Jun Jie², Ruifeng Wang¹, Shihao Zhang²

Energy Engineering, Vol.118, No.4, pp. 947-959, 2021, DOI:10.32604/EE.2021.014535

Abstract As a surface functional material, super-hydrophobic coating has great application potential in wind turbine blade anti-icing, self-cleaning and drag reduction. In this study, ZnO and SiO₂ multi-scale superhydrophobic coatings with mechanical flexibility were prepared by embedding modified ZnO and SiO₂ nanoparticles in PDMS. The prepared coating has a higher static water contact angle (CA is 153°) and a lower rolling angle (SA is 3.3°), showing excellent super-hydrophobicity. Because of its excellent superhydrophobic ability and micro-nano structure, the coating has good anti-icing ability. Under the conditions of −10°C and 60% relative humidity, the coating can delay the freezing time by 1511S,… More >

Younes Noorollahi^1,2,*, Mohammad-Javad Ziabakhsh Ganji¹, Mohammadmahdi Rezaei^1,2, Mojtaba Tahani³

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.2, pp. 515-532, 2021, DOI:10.32604/cmes.2021.012386

Abstract

Nowadays, concerns arise because of the depletion of fossil fuel resources that forced scientists to develop new energy extraction methods. One of these renewable resources is tidal energy, where Iran has this potential significantly. There are many ways to obtain the kinetic energy of the fluid flow caused by the moon’s gravitational effect on seas. Using horizontal axis tidal turbines is one of the ways to achieve the kinetic energy of the fluid. Since this type of turbine has similar technology to horizontal axis wind turbines, they may be an appropriate choice for constructing a tidal power plant in Iran.… More >

Makoto Yamamoto^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.23, No.1, pp. 19-19, 2021, DOI:10.32604/icces.2021.08478

Abstract In a turbine of a jet engine, deposition phenomenon is often observed. Deposition is a phenomenon that particles such as volcanic ash, sand and dust passing through a combustion chamber of a jet engine are melt, rapidly cooled and then accumulate on the turbine blade and end-wall surfaces. Deposition is one of critical problems when aircraft flies in a cloud with many particles. Obviously, deposition can degrade the aerodynamic performance of the turbine blade and vane, and make partial or complete blockage of film-cooling holes. As the result, deposition deteriorates safety and life time of the turbine. In the past… More >

Masaya Suzuki^1,*, Manabu Ueno², Koji Fukudome², Yoji Okita¹, Makoto Yamamoto²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.23, No.1, pp. 14-14, 2021, DOI:10.32604/icces.2021.08337

Abstract Recently, ceramic matrix composites (CMCs) are expected to utilize for the components of gas turbine engines due to its low density, high strength, and high rigidity in the high-temperature condition. The environmental barrier coating (EBC) is a key technology for the practical application of CMC to prevent surface regression from particulate and water vapor environments. However, the anti-erosion characteristics of CMC and EBC have not been clarified. In the present study, the authors performed numerical simulations of particulate erosion phenomena in a high-pressure turbine first stage to investigate the differences in the damage pattern and the performance between particle sizes.… More >

Qian Xu^1,*, Haitao Wang^1,2, Zhenhua Chen³, Zhigang Huang³, Pan Hu¹

Structural Durability & Health Monitoring, Vol.15, No.1, pp. 39-52, 2021, DOI:10.32604/sdhm.2021.014815

Abstract Crack detection in an aerospace turbine disk is essential for aircraft- quality detection. With the unique circular stepped structure and superalloy material properties of aerospace turbine disk, it is difficult for the traditional ultrasonic testing method to perform efficient and accurate testing. In this study, ultrasound phased array detection technology was applied to the non-destructive testing of aviation turbine disks: (i) A phased array ultrasonic c-scan device for detecting aerospace turbine disk cracks (PAUDA) was developed which consists of phased array ultrasonic, transducers, a computer, a displacement encoder, and a rotating scanner; (ii) The influence of the detection parameters include… More >

Anfeng Zhu, Zhao Xiao, Qiancheng Zhao^*

Energy Engineering, Vol.118, No.3, pp. 549-563, 2021, DOI:10.32604/EE.2021.014177

Abstract Due to the frequent changes of wind speed and wind direction, the accuracy of wind turbine (WT) power prediction using traditional data preprocessing method is low. This paper proposes a data preprocessing method which combines POT with DBSCAN (POT-DBSCAN) to improve the prediction efficiency of wind power prediction model. Firstly, according to the data of WT in the normal operation condition, the power prediction model of WT is established based on the Particle Swarm Optimization (PSO) Arithmetic which is combined with the BP Neural Network (PSO-BP). Secondly, the wind-power data obtained from the supervisory control and data acquisition (SCADA) system… More >