Karim Amrani^1,*, Eugenia Rossi di Schio^2,*, Mohamed Bouzit³, Abderrahim Mokhefi^1,4, Abdelkader Aris¹, Cherif Belhout³, Paolo Valdiserri²

Frontiers in Heat and Mass Transfer, Vol.23, No.1, pp. 185-206, 2025, DOI:10.32604/fhmt.2025.059833 - 26 February 2025

Abstract The present study focuses on the flow of a yield-stress (Bingham) nanofluid, consisting of suspended Fe₃O₄ nanoparticles, subjected to a magnetic field in a backward-facing step duct (BFS) configuration. The duct is equipped with a cylindrical obstacle, where the lower wall is kept at a constant temperature. The yield-stress nanofluid enters this duct at a cold temperature with fully developed velocity. The aim of the present investigation is to explore the influence of flow velocity (Re = 10 to 200), nanoparticle concentration ( = 0 to 0.1), magnetic field intensity (Ha = 0 to 100), and… More >

Yiming Rongyang¹, Zhenyue Yu¹, Ruisheng Liang^2,*, Wei Su¹, Jianjian Wei^2,3

Frontiers in Heat and Mass Transfer, Vol.23, No.1, pp. 279-298, 2025, DOI:10.32604/fhmt.2025.059637 - 26 February 2025

Abstract Data center cooling systems are substantial energy consumers, and managing the heat generated by electronic devices is becoming more complex as chip power levels continue to rise. The single-phase immersion cooling (SPIC) server with oil coolant is numerically investigated using the validated Re-Normalization Group (RNG) k-ε model. For the investigated scenarios where coolant velocity at the tank inlet is 0.004 m/s and the total power is 740 W, the heat transfer between the heat sinks and the coolant is dominated by natural convection, although forced convection mediates the overall heat transfer inside the tank. The maximum… More >

Yao Zhang¹, Hong Lan^1,3, Jiye Zhang^1,*, Lu Cai², Yuzhe Ma¹

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.12, pp. 2789-2808, 2024, DOI:10.32604/fdmp.2024.055418 - 23 December 2024

Abstract In this study, the unsteady Reynolds-averaged Navier–Stokes algorithm coupled with the Discrete Phase Model (DPM) was used to study the accumulation of snow in the bogie region of a high-speed train under crosswind conditions. Moreover, the impact of active blowing schemes on the airflow around the bogie and the dynamics and deposition of snow particles were also assessed. According to the results: in the crosswind environment, active blowing changes the flow field in the bogie area, reducing the flow of air coming from the windward side and bottom of the bogie. The trajectory of snow… More >

Jiaming Zhan^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.31, No.4, pp. 1-1, 2024, DOI:10.32604/icces.2024.011189

Abstract Calcium fluoride (CaF₂) exhibits excellent optical properties, making it a promising candidate for preparing optical components. The actual applications underscore the importance of enhancing the ductile machining of such a difficult-to-machine material. This study starts by investigating the influence of thermal gradient fields on the mechanical behaviors of CaF₂ single crystal experimentally and theoretically, revealing the potential deformation mechanisms under various thermal additions. On this basis, a novel laser-assisted machining (LAM) scheme was proposed to enhance the deformability and machinability of CaF₂ single crystal by tailoring local thermal fields. The laser heating spot within the work material… More >

Jingjing Liu¹, Long Yu^1,*, Xiaoyan Li², Jing Liu²

The International Conference on Computational & Experimental Engineering and Sciences, Vol.29, No.3, pp. 1-1, 2024, DOI:10.32604/icces.2024.012234

Abstract Owing to uncontrollable deformation during the launching process, significant hazards such as airbag blast failure can be observed, which can cause severe damage to surrounding structures. Involving gas-solid coupling and nonlinear damage, the analysis and evaluation of airbag blasts are complex. Therefore, an effective method to analyze the possible blast behavior by coupling smoothed particle hydrodynamics (SPH) and the finite element method (FEM) has been presented in this study. First, a single airbag compression model was established to calculate the stiffness curve and the rationality of the numerical method was verified through comparison with experiments.… More >

Yasushi Koito^1,*, Akira Fukushima²

Frontiers in Heat and Mass Transfer, Vol.22, No.3, pp. 869-887, 2024, DOI:10.32604/fhmt.2024.050910 - 11 July 2024

Abstract Thermal and fluid-flow characteristics were numerically analyzed for ultra-thin heat pipes. Many studies have been conducted for ultra-thin heat pipes with a centered wick structure, but this study focused on separated wick structures to increase the evaporation/condensation surface areas within the heat pipe and to reduce the concentration of heat flux within the wick structure. A mathematical heat-pipe model was made in the three-dimensional coordinate system, and the model consisted of three regions: a vapor channel, liquid-wick, and container wall regions. The conservation equations for mass, momentum, and energy were solved numerically with boundary conditions… More >

Ivan Sboev^1,*, Tatyana Lyubimova^2,3, Konstantin Rybkin³, Michael Kuchinskiy^2,3

FDMP-Fluid Dynamics & Materials Processing, Vol.20, No.6, pp. 1425-1439, 2024, DOI:10.32604/fdmp.2024.051341 - 27 June 2024

Abstract The intensification of physicochemical processes in the sonochemical reactor chamber is widely used in problems of synthesis, extraction and separation. One of the most important mechanisms at play in such processes is the acoustic cavitation due to the non-uniform distribution of acoustic pressure in the chamber. Cavitation has a strong impact on the surface degradation mechanisms. In this work, a numerical calculation of the acoustic pressure distribution inside the reactor chamber was performed using COMSOL Multiphysics. The numerical results have revealed the dependence of the structure of the acoustic pressure field on the boundary conditions More > Graphic Abstract

Ali Shokor Golam^*

Frontiers in Heat and Mass Transfer, Vol.22, No.2, pp. 633-653, 2024, DOI:10.32604/fhmt.2024.050218 - 20 May 2024

Abstract The thermal-hydraulic performance of plain tubes with and without wire coils in turbulent regimes is investigated experimentally and numerically. The effects of wire coil distribution (circular cross section) within the tube were explored experimentally, and water was employed as the working fluid. The numerical simulation was carried out using software programmer ANSYS Fluent 2019 R3 using the finite-volume approach. In the turbulent regime, six cross-sectioned wire coils were analyzed, including: circular, rectangular, hexagonal, square, star shape, and triangle. The utilization of a tube with a wire coil has been shown to increase heat transfer rate More >

Liqun Zhou^1,*, Weilin Yang¹, Chaojie Li², Shi Lin³

Frontiers in Heat and Mass Transfer, Vol.22, No.1, pp. 157-173, 2024, DOI:10.32604/fhmt.2023.045135 - 21 March 2024

Abstract The power density of electronic components grows continuously, and the subsequent heat accumulation and temperature increase inevitably affect electronic equipment’s stability, reliability and service life. Therefore, achieving efficient cooling in limited space has become a key problem in updating electronic devices with high performance and high integration. Two-phase immersion is a novel cooling method. The computational fluid dynamics (CFD) method is used to investigate the cooling performance of two-phase immersion cooling on high-power electronics. The two-dimensional CFD model is utilized by the volume of fluid (VOF) method and Reynolds Stress Model. Lee’s model was employed… More > Graphic Abstract

Di Peng^1,2, Guoqing Chen¹, Jiale Yan^1,*, Shiping Wang^2,*

CMES-Computer Modeling in Engineering & Sciences, Vol.139, No.3, pp. 2947-2964, 2024, DOI:10.32604/cmes.2024.047265 - 11 March 2024

Abstract Cavitation is a prevalent phenomenon within the domain of ship and ocean engineering, predominantly occurring in the tail flow fields of high-speed rotating propellers and on the surfaces of high-speed underwater vehicles. The re-entrant jet and compression wave resulting from the collapse of cavity vapour are pivotal factors contributing to cavity instability. Concurrently, these phenomena significantly modulate the evolution of cavitation flow. In this paper, numerical investigations into cloud cavitation over a Clark-Y hydrofoil were conducted, utilizing the Large Eddy Simulation (LES) turbulence model and the Volume of Fluid (VOF) method within the OpenFOAM framework. More > Graphic Abstract