Xin Guan^*, Yuqi Xie, Shuaijie Wang, Mingyang Li, Shiwei Wu

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.9, pp. 2045-2058, 2024, DOI:10.32604/fdmp.2024.049671 - 23 August 2024

Abstract The effects of the erosion present on the leading edge of a wind turbine airfoil (DU 96-W-180) on its aerodynamic performances have been investigated numerically in the framework of a SST k–ω turbulence model based on the Reynolds Averaged Navier-Stokes equations (RANS). The results indicate that when sand-induced holes and small pits are involved as leading edge wear features, they have a minimal influence on the lift and drag coefficients of the airfoil. However, if delamination occurs in the same airfoil region, it significantly impacts the lift and resistance characteristics of the airfoil. Specifically, as More >

Xin Guan^1,2,*, Mingyang Li¹, Shiwei Wu¹, Yuqi Xie¹, Yongpeng Sun¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.9, pp. 2029-2043, 2024, DOI:10.32604/fdmp.2024.049499 - 23 August 2024

Abstract The focus of this research was on the equivalent particle roughness height correction required to account for the presence of ice when determining the performances of wind turbines. In particular, two icing processes (frost ice and clear ice) were examined by combining the FENSAP-ICE and FLUENT analysis tools. The ice type on the blade surfaces was predicted by using a multi-time step method. Accordingly, the influence of variations in icing shape and ice surface roughness on the aerodynamic performance of blades during frost ice formation or clear ice formation was investigated. The results indicate that More >

Yuanjun Dai^1,2,3,*, Zetao Deng¹, Baohua Li², Lei Zhong¹, Jianping Wang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.7, pp. 1517-1537, 2024, DOI:10.32604/fdmp.2024.046828 - 23 July 2024

Abstract A combined experimental and numerical research study is conducted to investigate the complex relationship between the structure and the aerodynamic performances of an Archimedes spiral wind turbine (ASWT). Two ASWTs are considered, a prototypical version and an improved version. It is shown that the latter achieves the best aerodynamic performance when the spread angles at the three sets of blades are α = 30°, α = 55°, α = 60°, respectively and the blade thickness is 4 mm. For a velocity V = 10 m/s, a tip speed ratio (TSR) = 1.58 and 2, the maximum C values More > Graphic Abstract

Abdul Sattar Laghari¹, Mohammad Waqas Chandio¹, Laveet Kumar^2,*, Mamdouh El Haj Assad³

Energy Engineering, Vol.121, No.8, pp. 2023-2038, 2024, DOI:10.32604/ee.2024.051082 - 19 July 2024

Abstract The selection of working fluid significantly impacts the geothermal ORC’s Efficiency. Using a mixture as a working fluid is a strategy to improve the output of geothermal ORC. In the current study, modelling and thermodynamic analysis of ORC, using geothermal as a heat source, is carried out at fixed operating conditions. The model is simulated in the Engineering Equation Solver (EES). An environment-friendly mixture of fluids, i.e., R245fa/R600a, with a suitable mole fraction, is used as the operating fluid. The mixture provided the most convenient results compared to the pure working fluid under fixed operating More >

Yuanjun Dai^1,2, Jingan Cui¹, Baohua Li^1,*, Cong Wang¹, Kunju Shi¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.4, pp. 771-786, 2024, DOI:10.32604/fdmp.2023.029584 - 28 March 2024

Abstract A numerical method has been used to analyze the flow field related to a NACA 0015 airfoil with and without a flap and assess the influence of the flap height and angle on the surface pressure coefficient, lift coefficient, and drag coefficient. The numerical results demonstrate that the flap can effectively improve the lift coefficient of the airfoil; however, at small attack angles, its influence is significantly reduced. When the angle of attack exceeds the critical stall angle and the flap height is 1.5% of the chord length, the influence of the flap becomes very More >

Xuhui Jiang¹, Xi Zhang¹, Song Wang¹, Ruiqiong Wang¹, Peng Zou¹, Jingzhou Lu², Xiaoxiao Li^2,*

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 193-216, 2024, DOI:10.32604/fhmt.2023.046832 - 21 March 2024

Abstract This study investigates the performance of a natural draft dry cooling tower group in crosswind conditions through numerical analysis. A comprehensive three-dimensional model is developed to analyze the steady-state and dynamic behavior of the towers. The impact of wind speed and direction on heat rejection capacity and flow patterns is examined. Results indicate that crosswinds negatively affect the overall heat transfer capacity, with higher crosswind speeds leading to decreased heat transfer. Notably, wind direction plays a significant role, particularly at 0°. Moreover, tower response time increases with higher crosswind speeds due to increased turbulence and More >

Peiheng He, Jiye Zhang^*, Lan Zhang, Jiaqi Wang, Yuzhe Ma

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.1, pp. 937-953, 2024, DOI:10.32604/cmes.2023.043700 - 30 December 2023

Abstract The running stability of high-speed train is largely constrained by the wheel-rail coupling relationship, and the continuous wear between the wheel and rail surfaces will profoundly affect the dynamic performance of the train. In recent years, under the background of increasing train speed, some scientific researchers have proposed a new idea of using the lift force generated by the aerodynamic wings (aero-wing) installed on the roof to reduce the sprung load of the carriage in order to alleviate the wear and tear of the wheel and rail. Based on the bidirectional running characteristics of high-speed… More >

Xueguang Meng¹, Zengshuang Chen¹, Yuxin Xie¹, Gang Chen^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.4, pp. 1-5, 2023, DOI:10.32604/icces.2023.09892

Abstract Many species generally choose highly organized movements to gain more performance advantages rather than alone in the animal world, such as V-formation and line formation in birds. Understanding the aerodynamic characteristics and flow variation of multi-flapping wings in formation flight could be applied to the formation design of new bionic flapping-wing aircraft. In this paper, the effects of unequal individual spacing on the aerodynamic performance and flow mechanism of three-dimensional three-flapping wings flying in tandem formation are investigated numerically at a low Reynolds number. The simulations include small and large spacings, as well as cases… More >

Zhonglu Lin^1,2, Dongfang Liang², Yu Zhang^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.27, No.3, pp. 1-9, 2023, DOI:10.32604/icces.2023.010442

Abstract Fish schools are capable of simultaneous linear acceleration. To reveal the underlying hydrodynamic mechanism, we numerically investigate how Reynolds number Re = 1000−2000, Strouhal number St = 0.2−0.7 and wavelength λ = 0.5−2 affects the mean net thrust of two side-by-side NACA0012 hydrofoils undulating in anti-phase. In total, 550 cases are simulated using immersed boundary method. The thrust is strengthened by wavelength and Strouhal number, yet only slightly by the Reynolds number. We apply the symbolic regression algorithm to formulate this relationship as a high-level summary. More >

He Wang¹, Xiangsheng Xu¹, Guanye Shen², Bian Jing^1,*

Energy Engineering, Vol.120, No.10, pp. 2251-2272, 2023, DOI:10.32604/ee.2023.028965 - 28 September 2023

Abstract There are issues with flexible DC transmission system such as a lack of control freedom over power flow. In order to tackle these issues, a DC power flow controller (DCPFC) is incorporated into a multi-terminal, flexible DC power grid. In recent years, a multi-port DC power flow controller based on a modular multi-level converter has become a focal point of research due to its simple structure and robust scalability. This work proposes a model predictive control (MPC) strategy for multi-port interline DC power flow controllers in order to improve their steady-state dynamic performance. Initially, the… More >