Experimental dataset for heat transfer with hybrid magnetic nanofluid in transition and turbulent regime

Efficient heat transfer is essential for optimizing the performance and safety of industrial and engineering systems. While nanofluids have demonstrated superior heat transfer efficiency compared to deionized water (DIW), research on Magnetic Hybrid Nanofluids (MHNFs) in forced convection heat transfer within transition and turbulent flow regimes remains limited. This dataset explores the thermal and hydrodynamic characteristics of MHNFs—specifically Fe₃O₄/TiO₂, Fe₃O₄/MgO, and Fe₃O₄/ZnO—flowing through a heated pipe. The study spans laminar, transition, and turbulent flow regimes, with suspension concentrations ranging from 0.00625% to 0.3%. The research is conducted in four phases, addressing MHNF stability, thermophysical properties, and heat transfer dynamics under varying conditions.<b>Phase 1: Stability and Thermophysical Properties</b><br>The first phase evaluates the effects of hybridization mixing ratio (HMR), nanoparticle size, and temperature on the stability and thermophysical properties of Fe₃O₄/TiO₂-DIW, Fe₃O₄/MgO-DIW, and Fe₃O₄/ZnO-DIW. Results show that Fe₃O₄/ZnO-DIW with an 80:20 HMR achieved the highest thermal conductivity enhancement (31.28%) and lowest viscosity at 50°C, ensuring an optimal balance. Fe₃O₄/TiO₂ (18 nm)-DIW exhibited the highest electrical conductivity (4.23 mS/cm) at 50°C. Temperature emerged as a critical factor influencing thermal conductivity, highlighting MHNFs' potential for advanced cooling applications, such as proton exchange membrane (PEM) fuel cells.<br><b>Phase 2: Heat Transfer Performance</b><br>This phase examines the heat transfer capabilities of Fe₃O₄/TiO₂ fluids across Reynolds numbers and volume fractions. Significant enhancements in the convective heat transfer coefficient (CHT) were observed, with optimal performance at lower concentrations:0.0125 vol.%: 26.33% improvement0.00625 vol.%: 24.30% improvementHigher concentrations (e.g., 0.3 vol.%) showed diminishing returns in CHT while inducing higher pressure drops.The Total Efficiency Index (TEI) peaked at 0.0125 vol.%, signifying the ideal balance between heat transfer improvement and hydraulic resistance.<b>Phase 3: Transition Flow Dynamics</b><br>Focusing on Fe₃O₄/MgO MHNFs, this phase revealed distinct thermal transport behavior. Results indicated delayed transition at higher Reynolds numbers compared to DIW. At 0.0125 vol.% and 0.00625 vol.%, maximum thermal transport enhancements of 31.6% and 30.2%, respectively, were achieved, offering a practical trade-off between efficiency and pressure loss.<br><b>Phase 4: Influence of Magnetic Fields</b><br>The final phase investigates the impact of magnetic field strength and waveforms on Fe₃O₄/TiO₂ nanofluids. Magnetic waveforms—sine, square, and triangular—enhanced heat transfer by 27.87%, 28.21%, and 26.74%, respectively, at 0.0125 vol.%. Optimal performance was observed at 60 Hz frequency and 4V voltage, demonstrating the potential of magnetic fields to significantly boost thermal performance.<br><b>Implications and Applications</b><br>These findings contribute to the understanding of MHNFs in forced convection heat transfer, offering actionable insights for energy-efficient thermal management in power generation, HVAC systems, and chemical processing. MHNFs demonstrate the ability to enhance heat transfer efficiency while minimizing pressure losses at low concentrations, presenting promising opportunities for advancing heat exchanger and thermal system design.

高效传热对于优化工业与工程系统的性能及安全至关重要。相较于去离子水（deionized water, DIW），纳米流体（nanofluids）已被证实具备更优异的传热效率，但针对磁混合纳米流体（Magnetic Hybrid Nanofluids, MHNFs）在过渡流与湍流流态下的强制对流换热（forced convection heat transfer）研究仍较为有限。本数据集探究了三类磁混合纳米流体——即Fe₃O₄/TiO₂、Fe₃O₄/MgO及Fe₃O₄/ZnO——在加热管道内流动时的热工与水力学特性。研究覆盖层流、过渡流及湍流流态（laminar, transition, turbulent flow regimes），悬浮液浓度范围为0.00625%至0.3%。该项研究分为四个阶段开展，围绕磁混合纳米流体的稳定性、热物理特性（thermophysical properties）以及不同工况下的传热动力学展开。
<b>第一阶段：稳定性与热物理特性</b><br>第一阶段评估了混合配比（hybridization mixing ratio, HMR）、纳米颗粒尺寸以及温度对Fe₃O₄/TiO₂-DIW、Fe₃O₄/MgO-DIW及Fe₃O₄/ZnO-DIW稳定性与热物理特性的影响。研究结果显示，混合配比为80:20的Fe₃O₄/ZnO-DIW在50℃下实现了最高的导热系数提升（31.28%）与最低的黏度，达成了最优平衡。Fe₃O₄/TiO₂（18 nm）-DIW在50℃下展现出最高的电导率（4.23 mS/cm）。温度被证实为影响导热系数的关键因素，凸显了磁混合纳米流体在先进冷却应用中的潜力，例如质子交换膜（proton exchange membrane, PEM）燃料电池。
<b>第二阶段：传热性能</b><br>本阶段探究了Fe₃O₄/TiO₂流体在不同雷诺数（Reynolds numbers）与体积分数下的传热能力。研究观测到对流换热系数（convective heat transfer coefficient, CHT）出现显著提升，且在较低浓度下达到最优性能：
0.0125 vol.%：提升26.33%
0.00625 vol.%：提升24.30%
更高浓度（如0.3 vol.%）的对流换热系数提升效果逐渐减弱，同时会引发更高的压降。总效率指数（Total Efficiency Index, TEI）在0.0125 vol.%时达到峰值，意味着该浓度下传热提升与水力阻力实现了理想平衡。
<b>第三阶段：过渡流动动力学</b><br>本阶段聚焦Fe₃O₄/MgO磁混合纳米流体，揭示了其独特的热传输行为。研究结果表明，相较于去离子水，该流体在更高雷诺数下出现了流动过渡延迟现象。在0.0125 vol.%与0.00625 vol.%浓度下，分别实现了31.6%与30.2%的最大热传输提升，在效率与压降之间实现了实用的权衡。
<b>第四阶段：磁场的影响</b><br>最后一阶段探究了磁场强度与波形对Fe₃O₄/TiO₂纳米流体的影响。在0.0125 vol.%浓度下，正弦波、方波与三角波三种磁场波形分别使传热性能提升27.87%、28.21%与26.74%。在60 Hz频率与4V电压下观测到最优性能，证实了磁场可显著提升热工性能的潜力。
<b>启示与应用</b><br>上述研究结果加深了学界对磁混合纳米流体在强制对流换热中特性的理解，为发电、暖通空调（Heating, Ventilation and Air Conditioning, HVAC）系统以及化工过程中的节能热管理提供了可落地的参考思路。磁混合纳米流体在低浓度下可提升传热效率同时最小化压降，为改进换热器与热系统设计提供了极具前景的方向。