Zhengqing Zhang^1,2,3,*, Xiaojun Yuan², Hui Wu²

FDMP-Fluid Dynamics & Materials Processing, Vol.21, No.12, pp. 2927-2943, 2025, DOI:10.32604/fdmp.2025.071115 - 31 December 2025

Abstract Frost accumulation on the evaporator fins of air source heat pumps (ASHPs) severely degrades heat transfer performance and overall system efficiency. To address this, the present study employs computational fluid dynamics (CFD) to investigate how fin spacing influences frosting behavior, emphasizing the coupled evolution of frost thickness, density, airflow, and temperature distribution within fin channels. Results reveal that fin spacing is a key parameter governing both the extent and rate of frost growth. Wider fin spacing enhances frost accumulation, with a final frost mass of 6.41 g at 12 mm, about 71.8% higher than at More >

Xiaoqin Zheng¹, Yuqing Wan¹, Qian Zhang², Liqin He², Shihao Tang¹, Qiguo Zhuang², Lihua Wang^2,*

Phyton-International Journal of Experimental Botany, Vol.94, No.12, pp. 3879-3892, 2025, DOI:10.32604/phyton.2025.073229 - 29 December 2025

Abstract To investigate endogenous hormone changes in “Hongyang” kiwifruit from overwintering buds to floral morphogenesis (bell-shaped flowering stage), systematic observations were conducted during the undifferentiated stage, axillary bud differentiation stage, and floral morphogenesis stage from late November 2023 to early April 2024. Paraffin sectioning was employed to examine floral bud morphology, while LC-MS targeted metabolomics quantified changes in 15 endogenous hormones across 8 classes. Results indicated floral bud differentiation commenced from late January to early February and concluded by mid-April, spanning approximately 70 days. Approximately 33 days after axillary bud initiation marked the axillary bud primordium… More >

Dong Hu^1,2, Lingxing Hu³, Facheng Qiu^3,*

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1865-1882, 2025, DOI:10.32604/fhmt.2025.073409 - 31 December 2025

Abstract With the acceleration of industrialization and urbanization, ammonia nitrogen pollution in water bodies has become increasingly severe, making the development of efficient and low-consumption wastewater treatment technologies highly significant. This study employs three-dimensional computational fluid dynamics (CFD) to investigate the cavitation mechanisms and flow field characteristics in a novel jet impingement-negative pressure ammonia removal reactor. The simulation, validated by experimental pressure data with a high degree of consistency, utilizes the Mixture model, the Realizable k-ε turbulence model, and the Schnerr-Sauer cavitation model. The results demonstrate that the flow velocity undergoes a substantial acceleration within the… More > Graphic Abstract

Shuo Wang^1,2,*, Huiming Wang^1,2, Ying Zhang^1,2, Zhiqiang Zhang^1,3, Li Jia^1,2

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1721-1740, 2025, DOI:10.32604/fhmt.2025.073226 - 31 December 2025

Abstract This experimental investigation was conducted on the flow boiling performance of refrigerant R134a in two types of parallel microchannels: sintered porous microchannels (PP-MCs) and smooth parallel microchannels (SP-MCs). The tests were performed under controlled conditions including an inlet subcooling of 5 ± 0.2°C, saturation temperature of 33°C, mass fluxes of 346 and 485 kg/m²·s, and a range of heat fluxes. Key findings reveal that the sintered porous microstructure significantly enhances bubble nucleation, reducing the wall superheat required for the onset of nucleate boiling (ONB) to only 0.13°C compared to 2.2°C in smooth channels. The porous structure… More >

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 >

Xiaolong Li, Hui Chen, Yingwen Liu, Peng Yang^*

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1767-1788, 2025, DOI:10.32604/fhmt.2025.070537 - 31 December 2025

Abstract Hazardous gas intrusion in tightly sealed and geometrically complex confined spaces, such as armored tanks, poses a critical threat to occupant health. The intricate internal structure of these systems may lead to non-intuitive pollutant transport pathways. However, the spatial and temporal evolution of these structures, as well as the intrinsic mechanisms of the purification systems, remain poorly elucidated. In this study, a high-fidelity, transient three-dimensional computational fluid dynamics (CFD) model was developed to simulate the leakage and dispersion of carbon monoxide (CO) and nitrogen dioxide (NO₂) using the RNG k-ε turbulence model. Scenarios with and without… More > Graphic Abstract

Ghinwa Al Mimar¹, Natrah Kamaruzaman^1,*, Kamil Talib Alkhateeb²

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1933-1956, 2025, DOI:10.32604/fhmt.2025.070118 - 31 December 2025

Abstract The pivotal role microchannels play in the thermal management of electronic components has, in recent decades, prompted extensive research into methods for enhancing their heat transfer performance. Among these methods, surface wettability modification was found to be highly effective owing to its significant influence on boiling dynamics and heat transfer mechanisms. In this study, we modified surface wettability using a nanocomposite coating composed of graphene nano plate (GNPs) and multi-walled carbon nanotubes (MWCNT) and then examined how the modification affected the transfer of boiling heat in microchannels. The resultant heat transfer coefficients for hydrophilic and… More >

J. Serrano-Arellano¹, M.I. Hernández-López¹, J. L. Chávez-Servín², E. V. Macias-Melo³, K. M. Aguilar-Castro^3,*

Frontiers in Heat and Mass Transfer, Vol.23, No.6, pp. 1741-1765, 2025, DOI:10.32604/fhmt.2025.069560 - 31 December 2025

Abstract A numerical study analyzed double diffusion caused by convective and radiative heat transfer in a greenhouse with and without internal humidity sources. Two cases were examined: one considering temperature and mass concentration gradients on vertical walls and another incorporating internal humidity sources, enhancing convective and diffusive flows. Four configurations were analyzed by varying the length of the greenhouse, and the Rayleigh number was calculated over a range from 2.29 × 10¹⁰ to 6.07 × 10¹². Simulations modeled the greenhouse interior six times a day (8:00 a.m. to 7:00 p.m.), accounting for external temperature, humidity, and solar More > Graphic Abstract

Du-Yi Wang¹, Shih-Chen Shi^1,*, Dieter Rahmadiawan^1,2

Journal of Polymer Materials, Vol.42, No.4, pp. 1075-1095, 2025, DOI:10.32604/jpm.2025.072263 - 26 December 2025

Abstract Polymethyl methacrylate (PMMA) is widely used in diverse applications such as protective components (e.g., automotive lamp covers and structural casings), optical devices, and biomedical products, owing to its lightweight nature and impact resistance. However, its surface hardness and wear resistance remain insufficient under prolonged exposure to abrasive environments. In this study, a multi-filler strategy with nano-silica (SiO₂), brominated lignin (Br-Lignin), and cellulose nanocrystals (CNCs) was employed to enhance PMMA tribological properties. SiO₂ provided localized reinforcement, Br-Lignin established stable network structures, and CNCs improved compactness, enabling strong synergistic effects. As a result, the composites achieved up to More >

Asgar Ali^1,*, Nayan Sardar², Poly Karmakar³, Sanatan Das⁴

CMES-Computer Modeling in Engineering & Sciences, Vol.145, No.3, pp. 3563-3626, 2025, DOI:10.32604/cmes.2025.074082 - 23 December 2025

Abstract Hybrid nanofluids have gained significant attention for their superior thermal and rheological characteristics, offering immense potential in energy conversion, biomedical transport, and electromagnetic flow control systems. Understanding their dynamic behavior under coupled magnetic, rotational, and reactive effects is crucial for the development of efficient thermal management technologies. This study develops a neuro-fuzzy computational framework to examine the dynamics of a reactive Cu–TiO₂–H₂O hybrid nanofluid flowing through a squarely elevated Riga tunnel. The governing model incorporates Hall and ion-slip effects, thermal radiation, and first-order chemical reactions under ramped thermo-solutal boundary conditions and rotational electromagnetic forces. Closed-form analytical… More >