He Wang^1,*, Ying He²

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.4, pp. 889-899, 2024, DOI:10.32604/fdmp.2023.042728

Abstract Magnetohydrodynamic (MHD) induction pumps are contactless pumps able to withstand harsh environments. The rate of fluid flow through the pump directly affects the efficiency and stability of the device. To explore the influence of induction pump settings on the related delivery speed, in this study, a numerical model for coupled electromagnetic and flow field effects is introduced and used to simulate liquid metal lithium flow in the induction pump. The effects of current intensity, frequency, coil turns and coil winding size on the velocity of the working fluid are analyzed. It is shown that the first three parameters have a… 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

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 evident. As the flap height… More >

Yilei Wang¹, Xin Sun¹, Guiping Zheng^2,3, Ahmar Rashid⁴, Sami Ullah⁵, Hisham Alasmary⁶, Muhammad Waqas^7,8,*

CMC-Computers, Materials & Continua, Vol.78, No.3, pp. 3909-3927, 2024, DOI:10.32604/cmc.2024.047767

Abstract The application of Intelligent Internet of Things (IIoT) in constructing distribution station areas strongly supports platform transformation, upgrade, and intelligent integration. The sensing layer of IIoT comprises the edge convergence layer and the end sensing layer, with the former using intelligent fusion terminals for real-time data collection and processing. However, the influx of multiple low-voltage in the smart grid raises higher demands for the performance, energy efficiency, and response speed of the substation fusion terminals. Simultaneously, it brings significant security risks to the entire distribution substation, posing a major challenge to the smart grid. In response to these challenges, a… More >

Yunchang Liu^1,*, Fei Wan¹, Chengwu Liang²

CMC-Computers, Materials & Continua, Vol.78, No.3, pp. 4343-4361, 2024, DOI:10.32604/cmc.2024.047211

Abstract Traffic flow prediction plays a key role in the construction of intelligent transportation system. However, due to its complex spatio-temporal dependence and its uncertainty, the research becomes very challenging. Most of the existing studies are based on graph neural networks that model traffic flow graphs and try to use fixed graph structure to deal with the relationship between nodes. However, due to the time-varying spatial correlation of the traffic network, there is no fixed node relationship, and these methods cannot effectively integrate the temporal and spatial features. This paper proposes a novel temporal-spatial dynamic graph convolutional network (TSADGCN). The dynamic… More >

Wei Chen, Nan Qiu^*, Xusheng Yang

Energy Engineering, Vol.121, No.4, pp. 987-1005, 2024, DOI:10.32604/ee.2023.045475

Abstract During the operation of a DC microgrid, the nonlinearity and low damping characteristics of the DC bus make it prone to oscillatory instability. In this paper, we first establish a discrete nonlinear system dynamic model of a DC microgrid, study the effects of the converter sag coefficient, input voltage, and load resistance on the microgrid stability, and reveal the oscillation mechanism of a DC microgrid caused by a single source. Then, a DC microgrid stability analysis method based on the combination of bifurcation and strobe is used to analyze how the aforementioned parameters influence the oscillation characteristics of the system.… More >

R. Madan Kumar¹, R. Srinivasa Raju², F. Mebarek-Oudina^3,*, M. Anil Kumar⁴, V. K. Narla²

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 15-34, 2024, DOI:10.32604/fhmt.2024.048045

Abstract The primary aim of this research endeavor is to examine the characteristics of magnetohydrodynamic Williamson nanofluid flow past a nonlinear stretching surface that is immersed in a permeable medium. In the current analysis, the impacts of Soret and Dufour (cross-diffusion effects) have been attentively taken into consideration. Using appropriate similarity variable transformations, the governing nonlinear partial differential equations were altered into nonlinear ordinary differential equations and then solved numerically using the Runge Kutta Fehlberg-45 method along with the shooting technique. Numerical simulations were then perceived to show the consequence of various physical parameters on the plots of velocity, temperature, and… More > Graphic Abstract

Ruiqiong Wang¹, Tiantian Du², Jinchen Cao^2,*, Guoqiang Wang³

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 129-139, 2024, DOI:10.32604/fhmt.2024.047825

Abstract With the advancement of oilfield extraction technology, since oil-water emulsions in waxy crude oil are prone to be deposited on the pipe wall, increasing the difficulty of crude oil extraction. In this paper, the mesoscopic dissipative particle dynamics method is used to study the mechanism of the crystallization and deposition adsorbed on the wall. The results show that in the absence of water molecules, the paraffin molecules near the substrate are deposited on the metallic surface with a horizontal morphology, while the paraffin molecules close to the fluid side are arranged in a vertical column morphology. In the emulsified system,… 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

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 the formation of vortices. The… More >

Mustafa Abdullah^*

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 141-156, 2024, DOI:10.32604/fhmt.2024.046788

Abstract This study investigates the influence of periodic heat flux and viscous dissipation on magnetohydrodynamic (MHD) flow through a vertical channel with heat generation. A theoretical approach is employed. The channel is exposed to a perpendicular magnetic field, while one side experiences a periodic heat flow, and the other side undergoes a periodic temperature variation. Numerical solutions for the governing partial differential equations are obtained using a finite difference approach, complemented by an eigenfunction expansion method for analytical solutions. Visualizations and discussions illustrate how different variables affect the flow velocity and temperature fields. This offers comprehensive insights into MHD flow behavior… More >

Fayi Yan^*, Xuejian Pei, He Lu, Shuzhen Zong

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 287-304, 2024, DOI:10.32604/fhmt.2023.045038

Abstract As compact and efficient heat exchange equipment, helically coiled tube-in-tube heat exchangers (HCTT heat exchangers) are widely used in many industrial processes. However, the thermal-hydraulic research of liquefied natural gas (LNG) as the working fluid in HCTT heat exchangers is rarely reported. In this paper, the characteristics of HCTT heat exchangers, in which LNG flows in the inner tube and ethylene glycol-water solution flows in the outer tube, are studied by numerical simulations. The influences of heat transfer characteristics and pressure drops of the HCTT heat transfers are studied by changing the initial flow velocity, the helical middle diameter, and… More >