Shengzhong Zhao¹, Daiyan Chen¹, Han Zhang^1,2,*, Junhao Yu¹, Lin Xu¹, Zhaoyi Zhuang¹, Fei Wang^1,*

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1907-1932, 2025, DOI:10.32604/fhmt.2025.071910 - 31 December 2025

Abstract A sealed portal could significantly alter the flame shape and smoke flow characteristics in inclined tunnel fires. In inclined tunnels, two typical sealing conditions could be defined, namely the upper portal sealed and the lower portal sealed. In this study, the effects of tunnel slope on flame shape, flame length, along with smoke mass flow rate and induced velocity at the tunnel portal, are numerically investigated. The results show that, in all scenarios, flames initially rise vertically but tilt toward the sealed portal during the quasi-steady stage, with the largest tilt angle observed in tunnels… More >

Li Niu¹, Yang Wang^1,*, Nan Lin², Yaoying Yue¹, Wenbin Fu¹, Elzat Tuhanjiang¹

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.6, pp. 1473-1487, 2025, DOI:10.32604/fdmp.2025.062623 - 30 June 2025

Abstract With the widespread use of polyethylene (PE) materials in gas pipelines, the problem related to the aging of these pipes has attracted increasing attention. Especially under complex environmental conditions involving temperature, humidity, and pressure changes, PE pipes are prone to oxidative degradation, which adversely affects their performance and service life. This study investigates the aging behavior of PE pipes used for gas transport under the combined effects of temperature (ranging from 80°C to 110°C) and pressure (0, 0.1, 0.2, and 0.3 MPa). By assessing the characteristics and thermal stability of the aged pipes, relevant efforts… More >

Walaa M. Hashim, Israa S. Ahmed, Ayad K. Khlief^*, Raed A. Jessam, Ameer Abed Jaddoa

Energy Engineering, Vol.122, No.6, pp. 2485-2501, 2025, DOI:10.32604/ee.2025.061630 - 29 May 2025

Abstract Achieving broadband solar thermal absorption via dilute nanofluids is still a daunting challenge since the absorption peaks of common metal particles are usually located in the visible part of the radiation spectrum. This paper aims to present the results of experimental investigations on the thermal performance of heat pipe-type evacuated solar collectors. The experimented system consists of 15 tubes, providing the hot nanofluid to 100-L storage in a closed flow loop. The solar collector with a gross area of 2.1 m² is part of the solar hot water test system located in Baghdad-Iraq. Al₂O₃ nanofluid at… More >

Zainab Mahdi Saleh^1,*, Riyadh S. Al-Turaihi¹, Zena Khalefa Kadhim²

Frontiers in Heat and Mass Transfer, Vol.23, No.2, pp. 615-650, 2025, DOI:10.32604/fhmt.2025.063404 - 25 April 2025

Abstract This study involved numerical simulations of a double tube heat exchanger using the ANSYS FLUENT program version 22. The study aims to examine methods for minimizing pressure loss and consequently enhancing the thermal performance index (TPI) of a heat exchanger fitted with wavy edge tape that is a heat recovery system (the hot air in simulation instead of t heat from the exhaust gases of the brick factory furnaces and return it to warm the heavy fuel oil by substituting the electrical heater with a heat exchanger to recuperate waste heat from the flue gases,… More >

Yijun Gao^1,2, Yong Wang^1,*, Qing Na¹, Jiawei Zhang¹, Aixiang Wu¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.11, pp. 2443-2458, 2024, DOI:10.32604/fdmp.2024.051385 - 28 October 2024

Abstract Filling methods in the mining industry can maximize the recovery of mineral resources and protect the underground and surface environments. In recent years, such methods have been widely used in metal mines where pipeline transportation typically plays a decisive role in the safety and stability of the entire filling system. Because the filling slurry contains a large percentage of solid coarse particles, the involved pipeline is typically eroded and often damaged during such a process. A possible solution is the so-called nesting repair technology. In the present study, nesting a 127 mm outer diameter pipeline… More >

Mudasar Zafar^1,2,3,*, Hamzah Sakidin¹, Abida Hussain¹, Loshini Thiruchelvam⁴, Mikhail Sheremet⁵, Iskandar Dzulkarnain³, Roslinda Nazar⁶, Abdullah Al-Yaari¹, Rizwan Safdar^7,8

CMES-Computer Modeling in Engineering & Sciences, Vol.141, No.2, pp. 1193-1211, 2024, DOI:10.32604/cmes.2024.049259 - 27 September 2024

Abstract This study aims to formulate a steady-state mathematical model for a three-dimensional permeable enclosure (cavity) to determine the oil extraction rate using three distinct nanoparticles, SiO₂, Al₂O₃, and Fe₂O₃, in unconventional oil reservoirs. The simulation is conducted for different parameters of volume fractions, porosities, and mass flow rates to determine the optimal oil recovery. The impact of nanoparticles on relative permeability ( and water is also investigated. The simulation process utilizes the finite volume ANSYS Fluent. The study results showed that when the mass flow rate at the inlet is low, oil recovery goes up. In addition, More >

Yanqun Yu^1,*, Wenhao Xu¹, Yahui Huangfu¹, Jinhai Liu^1,2, Bensheng Wang¹, Kai Liu¹

Energy Engineering, Vol.121, No.6, pp. 1521-1533, 2024, DOI:10.32604/ee.2024.047986 - 21 May 2024

Abstract China’s unconventional gas fields have a large number of low-productivity and low-efficiency wells, many of which are located in remote and environmentally harsh mountainous areas. To address the long-term stable production of these gas wells, plunger-lift technology plays an important role. In order to fully understand and accurately grasp the drainage and gas production mechanisms of plunger-lift, a mechanical model of plunger-liquid column uplift in the plunger-lift process was established, focusing on conventional plunger-lift systems and representative wellbore configurations in the Linxing region. The operating casing pressure of the plunger-lift process and the calculation method… More >

Huda Adel Hassan Ali, Ameer Abed Jaddoa^*, Jafaar Mohamme Daif

Frontiers in Heat and Mass Transfer, Vol.21, pp. 443-465, 2023, DOI:10.32604/fhmt.2023.042288 - 30 November 2023

Abstract This paper is twofold. First, the effect of non-linear thermophysical property variation was presented using supercritical carbon dioxide (SCO₂) around the thermodynamic pivotal point. The second part exhibits an experimental examination of the heat transfer (HT) behaviour of SCO₂ in a helical tube with a hydraulic diameter of 2 mm at different mass fluxes (MF), heat fluxes (HF), and pressures (P). The experiments were carried out based on various pressures, mass fluxes, and heat fluxes for both scenarios. CO₂ was cooled in a 2 mm diameter serpentine tube made of copper material. The experimental results showed that More > Graphic Abstract

Kehuan Xie¹, Longhai Yu^2,3, Chuanchang Li^1,*

Energy Engineering, Vol.120, No.12, pp. 2903-2915, 2023, DOI:10.32604/ee.2023.027636 - 29 November 2023

Abstract Vanadium redox flow battery (VRFB) is considered one of the most potential large-scale energy storage technologies in the future, and its electrolyte flow rate is an important factor affecting the performance of VRFB. To study the effect of electrolyte flow rate on the performance of VRFB, the hydrodynamic model is established and a VRFB system is developed. The results show that under constant current density, with the increase of electrolyte flow rate, not only the coulombic efficiency, energy efficiency, and voltage efficiency will increase, but also the capacity and energy discharged by VRFB will also More >

Yangyang Tian^a , Zhuo Chen^b,* , Qi Zhuang^c

Frontiers in Heat and Mass Transfer, Vol.20, pp. 1-11, 2023, DOI:10.5098/hmt.20.26

Abstract The cyclone separator has remarkable amplification effect, which is an important factor affecting its separation efficiency and pressure drop. The numerical simulation of Stairmand cyclone separators with cylinder diameters of 200, 280, 400, 480 and 600mm after geometric similarity amplification was carried out by ANSYS software. RSM model was used for gas phase and DPM model was used for particle phase. The results show that after the cyclone size is enlarged geometrically, the tangential velocity tends to increase with the increase of the cyclone barrel diameter at the same inlet gas velocity, which leads to… More >