Qiang Liu¹, Rujun Wang¹, Yintao Zhang¹, Chong Sun¹, Meichun Yang¹, Yuliang Su^2,*, Wendong Wang², Ying Shi², Zheng Chen²

Energy Engineering, Vol.121, No.10, pp. 2797-2823, 2024, DOI:10.32604/ee.2024.052007 - 11 September 2024

Abstract Deep condensate gas reservoirs exhibit highly complex and variable phase behaviors, making it crucial to understand the relationship between fluid phase states and flow patterns. This study conducts a comprehensive analysis of the actual production process of the deep condensate gas well A1 in a certain oilfield in China. Combining phase behavior analysis and CMG software simulations, the study systematically investigates phase transitions, viscosity, and density changes in the gas and liquid phases under different pressure conditions, with a reservoir temperature of 165°C. The research covers three crucial depletion stages of the reservoir: single-phase flow,… More >

Benxin Li^*, Xuanming Chang

Energy Engineering, Vol.121, No.10, pp. 3001-3018, 2024, DOI:10.32604/ee.2024.051332 - 11 September 2024

Abstract The increasingly large number of electric vehicles (EVs) has resulted in a growing concern for EV charging station load prediction for the purpose of comprehensively evaluating the influence of the charging load on distribution networks. To address this issue, an EV charging station load prediction method is proposed in coupled urban transportation and distribution networks. Firstly, a finer dynamic urban transportation network model is formulated considering both nodal and path resistance. Then, a finer EV power consumption model is proposed by considering the influence of traffic congestion and ambient temperature. Thirdly, the Monte Carlo method… More > Graphic Abstract

Haowei Hu^1,2,*, Qi Wang¹, Xinnuo Chen¹, Qin Li³, Mu Du⁴, Dong Niu^5,*

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 1245-1259, 2024, DOI:10.32604/fhmt.2024.054223 - 30 August 2024

Abstract To investigate the microscopic mechanism underlying the influence of surface-chemical gradient on heat and mass recovery, a molecular dynamics model including droplet condensation and transport process has been developed to examine heat and mass recovery performance. This work aimed at identify optimal conditions for enhancing heat and mass recovery through the combination of wettability gradient and nanopore transport. For comprehensive analysis, the structure in the simulation was categorized into three distinct groups: a homogeneous structure, a small wettability gradient, and a large wettability gradient. The homogeneous surface demonstrated low efficiency in heat and mass transfer, More >

Haowei Hu^1,2,*, Xinnuo Chen¹, Qi Wang¹, Qin Li³, Dong Niu⁴, Mu Du^5,*

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 1071-1085, 2024, DOI:10.32604/fhmt.2024.054218 - 30 August 2024

Abstract The self-driven behavior of droplets on a functionalized surface, coupled with wetting gradient and wedge patterns, is systematically investigated using molecular dynamics (MD) simulations. The effects of key factors, including wedge angle, wettability, and wetting gradient, on the droplet self-driving effect is revealed from the nanoscale. Results indicate that the maximum velocity of droplets on hydrophobic wedge-shaped surfaces increases with the wedge angle, accompanied by a rapid attenuation of driving force; however, the average velocity decreases with the increased wedge angle. Conversely, droplet movement on hydrophilic wedge-shaped surfaces follows the opposite trend, particularly in terms… More >

Zhenzhen Liu, Hua Zhang^*, Zilong Wang, Yugang Zhao

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 1087-1105, 2024, DOI:10.32604/fhmt.2024.053851 - 30 August 2024

Abstract The exploration of performance and prediction of environmentally friendly refrigerant physical properties represents a critical endeavor. Equilibrium molecular dynamics simulations were employed to investigate the density and transport properties of propane and ethane at ultra-low temperatures under evaporative pressure conditions. The results of the density simulation of the evaporation conditions of the blends proved the validity of the simulation method. Under identical temperature and pressure conditions, increasing the proportion of R170 in the refrigerant blends leads to a density decrease while the temperature range in which the gas-liquid phase transition occurs is lower. The analysis More >

Zakaria Triki¹, Ahmed Selloum¹, Younes Chiba¹, Hichem Tahraoui^1,2, Dorsaf Mansour³, Abdeltif Amrane^4,*, Meriem Zamouche⁵, Mohammed Kebir⁶, Jie Zhang⁷

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 1107-1128, 2024, DOI:10.32604/fhmt.2024.052223 - 30 August 2024

Abstract Refrigeration plays a significant role across various aspects of human life and consumes substantial amounts of electrical energy. The rapid advancement of green cooling technology presents numerous solar-powered refrigeration systems as viable alternatives to traditional refrigeration equipment. Exergy analysis is a key in identifying actual thermodynamic losses and improving the environmental and economic efficiency of refrigeration systems. In this study exergy analyze has been conducted for a solar-powered vapor compression refrigeration (SP-VCR) system in the region of Ghardaïa (Southern Algeria) utilizing R1234ze(E) fluid as an eco-friendly substitute for R134a refrigerant. A MATLAB-based numerical model was… More >

Mekonnen S. Ayano^1,*, Thokozani N. Khumalo¹, Stephen T. Sikwila², Stanford Shateyi³

Frontiers in Heat and Mass Transfer, Vol.22, No.4, pp. 1153-1169, 2024, DOI:10.32604/fhmt.2024.048474 - 30 August 2024

Abstract The present paper examines the temperature-dependent viscosity and thermal conductivity of a micropolar silver ()−Magnesium oxide () hybrid nanofluid made of silver and magnesium oxide over a rotating vertical cone, with the influence of transverse magnetic field and thermal radiation. The physical flow problem has been modeled with coupled partial differential equations. We apply similarity transformations to the non-dimensionalized equations, and the resulting nonlinear differential equations are solved using overlapping grid multidomain spectral quasilinearization method. The flow behavior for the fluid is scrutinized under the impact of diverse physical constraints, which are illustrated graphically. The More >

Haibo Wang¹, Hongwei Gao^1,*, Pai Jiang¹, Matthieu De Mari², Panzer Gu³, Yinsheng Liu¹

Journal on Internet of Things, Vol.6, pp. 17-41, 2024, DOI:10.32604/jiot.2024.054791 - 26 August 2024

Abstract In the 6G Internet of Things (IoT) paradigm, unprecedented challenges will be raised to provide massive connectivity, ultra-low latency, and energy efficiency for ultra-dense IoT devices. To address these challenges, we explore the non-orthogonal multiple access (NOMA) based grant-free random access (GFRA) schemes in the cellular uplink to support massive IoT devices with high spectrum efficiency and low access latency. In particular, we focus on optimizing the backoff strategy of each device when transmitting time-sensitive data samples to a multiple-input multiple-output (MIMO)-enabled base station subject to energy constraints. To cope with the dynamic varied channel… More >

Guowei Feng¹, Qing Li^2,3, Yang Wang^1,*, Nan Lin⁴, Sixi Zha¹, Hang Dong¹, Ping Chen⁵, Minjun Zheng⁶

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.9, pp. 2139-2161, 2024, DOI:10.32604/fdmp.2024.053941 - 23 August 2024

Abstract High-density polyethylene (HDPE) pipes have gradually become the first choice for gas networks because of their excellent characteristics. As the use of pipes increases, there will unavoidably be a significant amount of waste generated when the pipes cease their operation life, which, if improperly handled, might result in major environmental contamination issues. In this study, the thermal degradation of polyethylene materials is simulated for different pressures (10, 50, 100, and 150 MPa) and temperatures (2300, 2500, 2700, and 2900 K) in the framework of Reactive Force Field (ReaxFF) molecular dynamics simulation. The main gas products,… More >

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 >