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  • Open Access

    ARTICLE

    Numerical Simulation and Experimental Study of Self-Supplied Aerostatic Air Float Piston in Miniature Linear Compressor

    Haifeng Zhu1,*, Zhenyu Chen1,*, Teng Lu1, Xiaoqin Zhi2
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2025.065830
    Abstract To meet the demand for miniaturized, compact, high-reliability, and long-life cryocoolers in small satellite platforms, the development of a linear Stirling cryocooler has been undertaken. Computational Fluid Dynamics (CFD) numerical simulation software was used to conduct simulation analyses, verifying the impact of porous media channel layout, eccentricity, viscous resistance coefficient of the porous media, and piston position on the designed aerostatic bearing piston employing self-supplied gas bearing technology. The calculation results indicate that both the aerostatic force and leakage increase synchronously with eccentricity, while the two designed gas lift channel layouts are capable of providing… More >

  • Open Access

    ARTICLE

    Experimental Study on Flow Boiling Characteristics of Low-GWP Fluid R1234yf in Microchannels Heat Sink

    Ying Zhang1,2, Chao Dang1,2,*, Zhiqiang Zhang1,2
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2025.067373
    (This article belongs to the Special Issue: Fluid Flow, Heat and Mass Transfer within Novel Cooling Structures)
    Abstract In this study, the flow boiling characteristics of R1234yf in parallel microchannels were experimentally investigated. The experiments were conducted with heat flux from 0 to 550 kW/m2, mass flux of 434, 727, and 1015 kg/(m2 s), saturation temperatures of 293, 298, and 303 K, and inlet sub-cooling of 5, 10, and 15 K. The analysis of the experimental results provides the following conclusions: a reduced mass flux and lower subcooling correspond to a diminished degree of superheat at the boiling inception wall; conversely, an elevated saturation temperature results in a reduced amount of superheat at the… More >

  • Open Access

    REVIEW

    A Review of Pressure Drop Characteristics and Optimization Measures of Two-Phase Flow with Low Boiling Point Working Fluids in Microchannels

    Zongyu Jie1,2, Chao Dang1,2,*, Qingliang Meng 3,4
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2025.066792
    (This article belongs to the Special Issue: Fluid Flow, Heat and Mass Transfer within Novel Cooling Structures)
    Abstract With the increasing miniaturization of systems and surging demand for power density, accurate prediction and control of two-phase flow pressure drop have become a core challenge restricting the performance of microchannel heat exchangers. Pressure drop, a critical hydraulic characteristic, serves as both a natural constraint for cooling systems and determines the power required to pump the working fluid through microchannels. This paper reviews the characteristics, prediction models, and optimization measures of two-phase flow pressure drop for low-boiling-point working fluids in microchannels. It systematically analyzes key influencing factors such as fluid physical properties, operating conditions, channel… More >

  • Open Access

    ARTICLE

    NACA Airfoils as Proposal for Heat Sink Fins: Optimization Investigation

    J. Luis Luviano-Ortiz, Julio Cesar Rodriguez-Mosqueda, Salvador Botello-Aceves, Yanan Camaraza-Medina*, Abel Hernandez-Guerrero
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2025.067466
    (This article belongs to the Special Issue: Advances in Heat and Mass Transfer: Integrating Numerical Methods with Artificial Intelligence, Machine Learning, and Data-Driven Approaches)
    Abstract This work presents a simulation analysis using a multi-objective evolutionary algorithm for the thermo-hydraulic behavior of staggered heat sinks whose fins have NACA 0040 airfoil profile. The results were compared with a conventional pin fin heat sink with a circular profile. This study searched for the best thermo-hydraulic performance by translational and rotational positioning of the fins. It is worth mentioning that this work was carried out in two stages. In the first stage, the thermo-hydraulic behavior of the heat sink was studied moving the location of the upper array above the X-axis from −2.25 to… More >

  • Open Access

    ARTICLE

    Improving the Performance of Thermoelectric Systems for Air Conditioning Using Different Configurations

    Hind Abdulrahman Mahmood, Ameer Abed Jaddoa*, Mohammed K. Al-Saadi
    Frontiers in Heat and Mass Transfer, DOI:10.32604/fhmt.2025.066075
    Abstract Thermoelectric air conditioning systems based on the Peltier effect had two modes: heating and cooling. In this work, the proposed design provides continuous improvement in COP from the first minute of operation. In cooling mode, the coefficient of performance (COP) was 1.176 due to the techniques used in this device, and it increased to 1.24 in the last minute of operation. Concerning the steady-state scenario, from the first minute, the Qc was larger than the W for the entire duration of the operation. The output temperature reaches 18.97°C, and the temperature on the cold side reaches… More >