Dengyun Li, Baiwen Du, Kai Zhu, Jicheng Yu^*, Siyuan Liang, Changxi Yue

Energy Engineering, Vol.120, No.11, pp. 2611-2628, 2023, DOI:10.32604/ee.2023.028282

Abstract Self-heating and electric field distribution are the primary factors affecting the accuracy of the Ultra High Voltage Direct Current (UHVDC) resistive divider. Reducing the internal temperature rise of the voltage divider caused by self-heating, reducing the maximum electric field strength of the voltage divider, and uniform electric field distribution can effectively improve the UHVDC resistive divider’s accuracy. In this paper, thermal analysis and electric field distribution optimization design of 1200 kV UHVDC resistive divider are carried out: (1) Using the proposed iterative algorithm, the heat dissipation and temperature distribution of the high voltage DC resistive divider are studied, and the… More >

Chunyan Zhang¹, Shuaishuai Wang^1,2, Yinhu Qiao^1,*, Zhiqiang Zhang^1,2

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.10, pp. 2661-2679, 2023, DOI:10.32604/fdmp.2023.028059

Abstract Numerical simulations are conducted to improve the energy acquisition efficiency of H-type vertical axis wind turbines through the optimization of the related blade airfoil aerodynamic performance. The Bézier curve is initially used to fit the curve profile of a NACA2412 airfoil, and the moving asymptote algorithm is then exploited to optimize the design of the considered H-type vertical-axis wind-turbine blade airfoil for a certain attack angle. The results show that the maximum lift coefficient of the optimized airfoil is 8.33% higher than that of the original airfoil. The maximum lift-to-drag ratio of the optimized airfoil exceeds the maximum lift-to-drag ratio… More > Graphic Abstract

Fahd N. Al-Wesabi^1,2,*, Murad A. A. Almekhlafi³, Huda G. Iskandar^2,4, Adnan Zain⁵, Saleh Alzahrani⁶, Mohammed Alamgeer⁶, Nadhem Nemri⁶, Sami Dhabi⁶, Mohammad Medani⁶, Ali. M. Al-Sharafi^2,7

CMC-Computers, Materials & Continua, Vol.69, No.2, pp. 1979-1994, 2021, DOI:10.32604/cmc.2021.018390

Abstract In recent years, there has been an increasing demand to improve cellular communication services in several aspects. The aspect that received the most attention is improving the quality of coverage through using smart antennas which consist of array antennas. this paper investigates the main characteristics and design of the three types of array antennas of the base station for better coverage through simulation (MATLAB) which provides field and strength patterns measured in polar and rectangular coordinates for a variety of conditions including broadsides, ordinary End-fire, and increasing directivity End-fire which is typically used in smart antennas. The method of analysis… More >