Experimental Thermal and Fluid Science最新文献_第5页

Bubble oscillations and dynamics under periodic electric fields 周期电场作用下气泡振荡与动力学

IF 3.3 2区工程技术 Q2 ENGINEERING, MECHANICAL

Experimental Thermal and Fluid Science

Pub Date : 2026-01-30 Epub Date: 2025-11-25 DOI: 10.1016/j.expthermflusci.2025.111668

Tianle Gu, Samuel Siedel

Understanding bubble dynamics under time-dependent electric fields is essential for applications in electrohydrodynamic(EHD) control, microfluidics, and phase-change heat transfer, but the interplay of polarization and Coulomb forces in leaky dielectric fluids is poorly understood. In this study, we experimentally investigated the growth and detachment of air bubbles injected into the leaky dielectric liquid HFE-7100 under periodic electric fields with square and sine waveforms at 50 and 100 Hz. High-speed imaging and image analysis revealed that EHD forces induced significant shape oscillations and strongly influenced bubble growth rates and detachment timing. Quantitatively, Fast Fourier Transform (FFT) analysis of the 100 Hz square wave data revealed dominant oscillation frequencies clustered between 135 Hz and 211 Hz. The response was highly dependent on the phase of bubble initiation, with polarity reversal often triggering detachment. Notably, under sine wave excitation, successive bubbles spontaneously organized into two alternating modes characterized by highly consistent aspect ratio evolution and volumetric growth. The bifurcation effect disappeared when a DC bias was added to the signal. These results demonstrate the critical role of waveform shape, frequency, and polarity in modulating bubble behavior in periodic fields, and provide new experimental insight into transient EHD effects in leaky dielectric fluids.

了解随时间电场作用下的气泡动力学对于电流体动力学（EHD）控制、微流体和相变传热的应用至关重要，但对泄漏介质流体中极化和库仑力的相互作用了解甚少。本文实验研究了在50 Hz和100 Hz的方波和正弦波周期电场作用下，注入漏电介质HFE-7100中的气泡的生长和脱离。高速成像和图像分析显示，EHD力会引起明显的形状振荡，并强烈影响气泡的生长速度和脱离时间。定量地，对100 Hz方波数据进行快速傅里叶变换（FFT）分析显示，主要振荡频率聚集在135 Hz和211 Hz之间。反应高度依赖于气泡起始的阶段，极性反转常常触发分离。值得注意的是，在正弦波激励下，连续气泡自发组织成两种交替模式，其特征是高度一致的宽高比演化和体积增长。当信号中加入直流偏置时，分岔效应消失。这些结果证明了波形形状、频率和极性对周期场中调制气泡行为的关键作用，并为泄漏介质流体中的瞬态EHD效应提供了新的实验见解。

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引用次数: 0

An experimental investigation of oil spray cooling heat transfer for electrical machine cooling 电机冷却用喷油冷却换热的实验研究

IF 3.3 2区工程技术 Q2 ENGINEERING, MECHANICAL

Experimental Thermal and Fluid Science

Pub Date : 2026-01-30 Epub Date: 2025-11-12 DOI: 10.1016/j.expthermflusci.2025.111656

Nicolas Brossardt , Sebastian Hoelle , Lars Zigan

Although oil spray cooling is a promising cooling concept for electrical engines with high power density, there is a lack of universal measurement data and correlations for design purposes. In this article, an experiment is designed specifically for this application using similarity theory in a generic spray-wall situation. The comprehensive investigation shows a clear dependence of the heat transfer on the oil mass flow density and the droplet energy on impact into the oil film formed on the heated windings. Also, the thermal interaction between the spray droplets and the surrounding air is found to be an essential mechanism in oil spray cooling heat transfer. The experimental results are eventually used to derive a Nusselt number correlation, which is valid for spray Reynolds numbers

R e_{D}

of

2.1 - 17.1

, oil Prandtl numbers

P r

of

63 - 108

and nozzle Weber numbers

W e_{d0}

of

5.6 - 56.6

.

虽然喷油冷却是一种很有前途的高功率密度电机冷却概念，但缺乏通用的测量数据和设计目的的相关性。在本文中，一个实验是专门为这种应用设计的，在一般的喷墙情况下使用相似理论。综合研究表明，热传递与油的质量、流量密度和液滴能量有明显的关系，而液滴能量与油膜的碰撞有明显的关系。同时，发现喷雾液滴与周围空气的热相互作用是油喷雾冷却传热的重要机制。最后利用实验结果推导出了Nusselt数相关性，该相关性适用于喷雾雷诺数ReD为2.1 ~ 17.1，油液普朗特数Pr为63 ~ 108，喷嘴韦伯数Wed0为5.6 ~ 56.6。

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引用次数: 0

Experimental determination of the heat transfer characteristics and buoyancy effects of supercritical R1234zeE flowing in a large diameter horizontal tube 超临界R1234zeE在大直径水平管内流动的传热特性及浮力效应的实验测定

IF 3.3 2区工程技术 Q2 ENGINEERING, MECHANICAL

Experimental Thermal and Fluid Science

Pub Date : 2026-01-30 Epub Date: 2025-11-17 DOI: 10.1016/j.expthermflusci.2025.111657

Jera Van Nieuwenhuyse , Steven Lecompte , Michel De Paepe

Heat transfer to supercritical refrigerants is applied in systems such as the transcritical organic Rankine cycle. For refrigerants under horizontal flow, research on heat transfer under these conditions is limited. In addition, most of the studies focus on small diameter tubes and on R134a, which has a high Global Warming Potential. However, results on one fluid cannot be directly translated to another one and studies on larger tube diameters are required to study the influence of buoyancy on heat transfer and the occurrence of heat transfer deterioration. In this work, local heat transfer measurements at the top, side and bottom of a heated horizontal tube with a large inner diameter of 22.9 mm were performed on R1234zeE, for various supercritical pressure levels, heat fluxes and mass fluxes. Pressure has no influence on heat transfer or buoyancy, indicating that buoyancy forces on the flow are strong under the considered operating conditions. Increasing mass flux has a positive effect on heat transfer, and this effect is stronger for the top of the tube at lower heat fluxes. A rise in heat flux reduces heat transfer, but this effect is dependent on applied pressure and mass flux. Buoyancy is enlarged with increasing heat flux and at higher heat flux, this effect becomes less strong when the flow is more developed. Finally, the prediction capability of several buoyancy criteria from literature were evaluated, where none of the criteria were directly applicable to the current dataset and an update of the threshold values is required.

超临界制冷剂的传热应用于跨临界有机朗肯循环等系统。对于水平流动的制冷剂，在这种条件下的传热研究是有限的。此外，大多数研究集中在小直径管和具有高全球变暖潜势的R134a上。然而，在一种流体上的结果不能直接转化到另一种流体上，为了研究浮力对换热的影响以及换热劣化的发生，需要在更大管径上进行研究。本文在R1234zeE上对一个内径22.9 mm的大加热水平管的顶部、侧面和底部进行了不同超临界压力水平、热流密度和质量通量的局部换热测量。压力对换热和浮力没有影响，说明在所考虑的工况下，流动受到的浮力较大。质量通量的增加对换热有积极的影响，并且在热流较低的情况下，这种影响在管的顶部更为明显。热通量的增加减少了热传递，但这种影响取决于施加的压力和质量通量。浮力随热流密度的增大而增大，当热流密度较大时，浮力随流动的发展而减弱。最后，对文献中几种浮力标准的预测能力进行了评估，其中没有一个标准直接适用于当前数据集，需要更新阈值。

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引用次数: 0

Multi-domain investigation of combustion instability in gas turbine engines using a uniaxial MEMS piezoelectric accelerometer 基于单轴MEMS压电加速度计的燃气轮机燃烧不稳定性多域研究

IF 3.3 2区工程技术 Q2 ENGINEERING, MECHANICAL

Experimental Thermal and Fluid Science

Pub Date : 2026-01-30 Epub Date: 2025-11-16 DOI: 10.1016/j.expthermflusci.2025.111659

P.Di Gloria , M.G.De Giorgi , M.A. Signore , L. Francioso

This work presents a multi-domain experimental characterization of combustion instabilities in a liquid-fueled swirling combustor operating with Jet-A1, combining high-speed optical imaging, dynamic pressure measurements, and structural vibration monitoring. Experiments were conducted at two global equivalence ratios (Φ = 0.36 and Φ = 0.18), representative of stable and ultra-lean unstable operating conditions. Flame dynamics were analyzed using Proper Orthogonal Decomposition (POD), Spectral POD (SPOD), and Cross-Fourier Transform (Cross-FFT), while pulsation mechanics were investigated through the Autocorrelation Function (ACF). Pressure fluctuations and structural vibrations were monitored using a commercial pressure sensor and an innovative uniaxial AlN-based piezoelectric MEMS accelerometer, fabricated via CMOS-compatible processes and characterized in terms of sensitivity, linearity, resonance, and hysteresis. Time-domain analysis revealed increased signal dispersion and intermittency at Φ = 0.18, while frequency-domain analysis showed that the MEMS accelerometer effectively captures transient components between 156 and 625 Hz, typical of turbulent combustion. Cross-spectral analysis demonstrated high coherence between accelerometer signals and dominant flame modes, highlighting the sensor’s capability to monitor structural dynamics and localized instabilities in real time. The results confirm that the MEMS accelerometer is a compact, non-intrusive, and reliable tool for real-time diagnostics of thermoacoustic instabilities, which can be integrated with optical and pressure measurements for advanced monitoring and control strategies. This combined approach offers valuable perspectives for developing advanced monitoring strategies and real-time control of gas turbine combustors.

本研究结合高速光学成像、动压测量和结构振动监测，对使用Jet-A1的液体燃料旋涡燃烧室的燃烧不稳定性进行了多域实验表征。实验在两个全局等价比（Φ = 0.36和Φ = 0.18）下进行，代表稳定和超精益不稳定工况。利用正交分解（POD）、谱分解（SPOD）和交叉傅立叶变换（Cross-FFT）分析了火焰动力学，并利用自相关函数（ACF）研究了脉动力学。使用商用压力传感器和创新的单轴铝基压电MEMS加速度计监测压力波动和结构振动，该加速度计通过cmos兼容工艺制造，并具有灵敏度，线性度，共振和滞后特性。时域分析表明，在Φ = 0.18时，信号色散和间歇性增加，而频域分析表明，MEMS加速度计有效捕获了156 - 625 Hz之间的瞬态分量，这是典型的湍流燃烧。交叉光谱分析表明，加速度计信号与主要火焰模式之间具有高度相干性，突出了传感器实时监测结构动力学和局部不稳定性的能力。结果证实，MEMS加速度计是一种紧凑、非侵入式、可靠的热声不稳定性实时诊断工具，可以与光学和压力测量相结合，实现先进的监测和控制策略。这种综合方法为开发先进的监测策略和燃气轮机燃烧室的实时控制提供了有价值的视角。

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引用次数: 0

Experimental assessment of velocity and narrow-band measurements in oxy-fuel combustion of pulverized walnut shells 核桃壳粉全氧燃烧速度和窄带测量的实验评定

IF 3.3 2区工程技术 Q2 ENGINEERING, MECHANICAL

Experimental Thermal and Fluid Science

Pub Date : 2026-01-30 Epub Date: 2025-11-12 DOI: 10.1016/j.expthermflusci.2025.111658

Burak Özer, Reinhold Kneer, Anna Maßmeyer

Self-sustained pulverized biomass swirl flames are investigated experimentally under oxy-fuel atmosphere concerning the effect of thermal load, and oxygen content of the oxidizer stream on flame characteristics. Experiments are conducted employing a swirl burner in a down-fired cylindrical chamber. Operating conditions are selected in ranges of thermal loads between

60 {k W}_{th}

to

100 {k W}_{th}

and oxidizer oxygen contents between 25 and 30 vol.-% while keeping the flame stoichiometry constant. Particle velocity profiles are obtained employing non-intrusive 2D laser Doppler velocimetry. Spectrally narrow-band imaging of the near burner region enables the identification of reaction zones via OH* radical emission imaging as well as regions of high particle temperature by imaging their thermal radiation. The results show that the occurrence of an fuel particle recirculation is related to the ratio of the momentum flow rate of swirled secondary stream over the momentum flow rate of the fuel with its carrying stream. By either reinforcing the flame thermal power or lowering the oxidizer oxygen content, the momentum ratio increases, progressively leading to the fuel particle recirculation at the central axis of the flame. In the flames with a recirculation of hot fuel particles towards the burner, homogeneous devolatilization and char combustion regions are observed in the radical emission of OH* and thermal radiation images, respectively.

实验研究了氧-燃料气氛下自燃生物质旋流火焰的热负荷和氧化剂流含氧量对火焰特性的影响。采用旋流燃烧器在下燃圆柱腔内进行了实验。在保持火焰化学计量常数不变的情况下，选择热负荷在60kWth至100kWth之间，氧化剂氧含量在25至30 vol.-%之间的工作条件。采用非侵入式二维激光多普勒测速法获得了粒子速度分布。近燃烧器区域的光谱窄带成像可以通过OH*自由基发射成像来识别反应区域，也可以通过热辐射成像来识别高颗粒温度区域。结果表明，燃料颗粒再循环的发生与二次旋流的动量流量与燃料与其携带流的动量流量之比有关。通过增强火焰热功率或降低氧化剂氧含量，动量比增加，逐渐导致燃料颗粒在火焰中轴线处再循环。在热燃料颗粒向燃烧器再循环的火焰中，OH*的自由基发射和热辐射图像分别观察到均匀的脱挥发和炭燃烧区域。

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引用次数: 0

Bubble breakup in the microchannels with a long constriction 气泡在微通道中破裂，具有较长的收缩

IF 3.3 2区工程技术 Q2 ENGINEERING, MECHANICAL

Experimental Thermal and Fluid Science

Pub Date : 2026-01-30 Epub Date: 2025-11-03 DOI: 10.1016/j.expthermflusci.2025.111640

Baolei Jiao , Lifeng Chen , Xuemin Yan , Xiaoda Wang

Bubble dynamics within contracting microchannels exhibit profound complexity, receiving a long-standing research focus. This study systematically investigated bubble behaviors in elongated constrictions both in the 2D and 3D pore-throat combinations. A high-speed imaging device captured the bubble evolution in structurally diverse constrictions, while the effects of gas–liquid flow rates and fluid properties were quantified to establish transitional boundaries between distinct flow regimes. Bubble breakup—a typical flow pattern—demonstrated notable disparities between 2D and 3D configurations. To elucidate these differences, interfacial dynamics were tracked to analyze breakup mechanisms during the constriction traversal. In both dimensional systems, bubble breakup was primarily driven by the drawing and squeezing forces exerted by the continuous phase. Crucially, in the 3D pore-throat combination, the intensified drawing forces and prolonged squeezing forces, significantly enhanced breakup propensity. Mutual squeezing among the daughter-bubbles induced asynchronous breakup events, yielding non-uniform daughter-bubble size distributions. A power-law relationship characterized the dependence of mean daughter-bubble size on the mother-bubble length and the superficial flow velocity, with the exponent critically governed by microchannel geometric parameters. This work will advance fundamental understanding of bubble breakup mechanics in confined geometries and provide actionable insights for microfluidic device design.

收缩微通道内的气泡动力学表现出深刻的复杂性，长期以来一直是研究的焦点。本研究系统地研究了二维和三维孔喉组合中细长收缩条件下的气泡行为。高速成像设备捕捉到了不同结构收缩条件下气泡的演化过程，同时对气液流速和流体性质的影响进行了量化，以建立不同流动状态之间的过渡边界。气泡破裂是一种典型的流动模式，在2D和3D形态之间表现出明显的差异。为了阐明这些差异，我们跟踪了界面动力学，分析了收缩穿越过程中的破裂机制。在这两个维度系统中，气泡破碎主要是由连续相施加的拉伸和挤压力驱动的。关键是，在三维孔喉组合中，拉拔力的增强和挤压力的延长显著增强了破裂倾向。泡沫之间的相互挤压导致了非同步破裂事件，产生了不均匀的泡沫大小分布。平均气泡大小与母泡长度和表面流速呈幂律关系，指数受微通道几何参数的严格控制。这项工作将促进对受限几何气泡破裂力学的基本理解，并为微流控装置的设计提供可行的见解。

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引用次数: 0

Influence of swirl on the thermo-acoustic characteristics of partially-premixed flames 旋流对部分预混火焰热声特性的影响

IF 3.3 2区工程技术 Q2 ENGINEERING, MECHANICAL

Experimental Thermal and Fluid Science

Pub Date : 2026-01-30 Epub Date: 2025-11-07 DOI: 10.1016/j.expthermflusci.2025.111653

Rajesh Sadanandan, Remesh R. Konat, I.R. Praveen Krishna

The influence of swirl strength on the flame characteristics and the naturally excited thermo-acoustic instabilities in a confined partially premixed flame is experimentally investigated. Variation in the swirl strength is achieved by varying the axial to tangential airflow momentum in an in-house developed swirl and bluffbody stabilized burner. Empirical mode decomposition analysis, along with Hilbert’s transformation of the acoustic and heat release data, is carried out to reveal the underlying oscillatory modes and their time–frequency representation. For a fixed global equivalence ratio (

ϕ_{g}

), the burner exhibited self-excited acoustic instability and decreased flame standoff distance under high swirl strengths. Temporal modulation of both acoustic and heat release oscillation has been observed during instability. The self-excited oscillations are found to be vortex-driven, and the thermo-acoustic coupling depends on the location of the heat release zone with respect to the local acoustic pressure of the standing wave inside the combustor. The study shows that modulating the swirl strength also makes it possible to disrupt or mitigate the thermo-acoustic coupling existing in the system.

实验研究了旋流强度对受限部分预混火焰特性和自然激发热声不稳定性的影响。旋流强度的变化是通过改变内部开发的旋流和崖体稳定燃烧器的轴向和切向气流动量来实现的。经验模态分解分析，以及希尔伯特对声学和热释放数据的变换，揭示了潜在的振荡模态及其时频表示。对于固定的全局等效比（ϕg），高旋流强度下燃烧器表现出自激声不稳定性，火焰距离减小。在不稳定期间观察到声和热释放振荡的时间调制。发现自激振荡是旋涡驱动的，热声耦合取决于放热区的位置相对于燃烧室内驻波的局部声压。研究表明，调节旋流强度也可以破坏或减轻系统中存在的热声耦合。

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引用次数: 0

Research on the rebound and fusion characteristics of high temperature aluminium droplets impact on aluminium liquid film 高温铝液滴冲击铝液膜的回弹与熔合特性研究

IF 3.3 2区工程技术 Q2 ENGINEERING, MECHANICAL

Experimental Thermal and Fluid Science

Pub Date : 2026-01-30 Epub Date: 2025-10-26 DOI: 10.1016/j.expthermflusci.2025.111633

Qinrui Xu, Jiang Li, Kang Li, Shihui Cheng

The rebound/fusion characteristics of high-temperature aluminium droplets impact on aluminium liquid film are crucial for accurately predicting the evolution of solid rocket motor slag deposition. In this study, the rebound and fusion characteristics of aluminium droplet impact on aluminium liquid film were systematically investigated through experimental research and direct numerical simulation (DNS). Electromagnetic induction heating and pneumatic driving technology are used to generate high-temperature aluminium droplets, combined with a high-speed camera to capture the impact transient process. For the numerical simulations, we use the Basilisk software with Volume of Fluid model. This model helps us understand how the gas film evolves and how the interfaces interact during droplet impact. The results show that the droplet impact results are dominated by Weber number (We), and the droplets rebound when We ≤ 5.4, while fusion occurs when We > 5.4. This critical condition applies to the dimensionless liquid film thickness of 20 ≤ H* ≤ 30 and the Ohnesorge number of 0.8 ≤ Oh ≤ 1.0 × 10^-3. The numerical simulation results showed that the wall effect was significant in the thin liquid film (H* < 1.5), with an inverted “hump” shape of the gas film and limited liquid film retraction. For thick liquid film (H* ≥ 1.5), the gas film forms an arc-shaped profile. We also establish a formula for the maximum dimensionless penetration depth of the liquid film, based on the Weber and Ohnesorge numbers. Additionally, we propose a prediction model for the rebound and fusion of high-surface-tension droplets on liquid films. This model is based on the liquid film surface arc length and energy analysis. This study reveals the kinetic mechanism of high-surface-tension droplet impact. It provides useful insights for predicting slag deposition in engines and optimizing thermal protection systems.

高温铝液滴冲击铝液膜的回弹/熔合特性对于准确预测固体火箭发动机熔渣过程的演变至关重要。本研究通过实验研究和直接数值模拟（DNS）两种方法，系统研究了铝液滴撞击铝液膜时的回弹和融合特性。采用电磁感应加热和气动驱动技术产生高温铝液滴，结合高速摄像机捕捉冲击瞬态过程。采用流体体积模型的Basilisk软件进行数值模拟。该模型有助于我们了解气膜的演变过程以及液滴撞击过程中界面的相互作用。结果表明：液滴撞击结果以韦伯数（We）为主，当We≤5.4时，液滴发生反弹，当We >； 5.4时，液滴发生融合。该临界条件适用于无量纲液膜厚度为20≤H*≤30，欧内格数为0.8≤Oh≤1.0 × 10-3。数值模拟结果表明，在薄液膜（H* < 1.5）中，壁面效应显著，气膜呈倒“驼峰”形状，液膜收缩有限。对于厚液膜（H*≥1.5），气膜呈弧形。我们还建立了基于Weber和Ohnesorge数的液膜最大无因次渗透深度公式。此外，我们还提出了高表面张力液滴在液体膜上的回弹和融合的预测模型。该模型基于液膜表面弧长和能量分析。本研究揭示了高表面张力液滴撞击的动力学机理。它为预测发动机中的渣沉积和优化热保护系统提供了有用的见解。

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引用次数: 0

Experimental investigation of flow and heat transfer characteristics in the bend region of matrix channel 基质通道弯曲区流动传热特性的实验研究

IF 3.3 2区工程技术 Q2 ENGINEERING, MECHANICAL

Experimental Thermal and Fluid Science

Pub Date : 2026-01-30 Epub Date: 2025-10-23 DOI: 10.1016/j.expthermflusci.2025.111632

Arun Chand , Nishab Ali , Andallib Tariq

Matrix cooling is gaining attention as an advanced internal cooling strategy for gas turbines, offering both enhanced mechanical integrity and superior heat transfer. However, the aerothermal behavior in bend regions, especially downstream of the matrix, remains insufficiently explored. This study presents a detailed experimental investigation of flow dynamics and heat transfer across the bend section that occurs downstream of the matrix channel. Two matrix configurations, i.e., (i) 3-subchannel (3SC) and (ii) 4-subchannel (4SC), are systematically studied at Reynolds numbers (Re) of 5,000, 7,500, and 10,000. High-resolution particle image velocimetry (PIV) and liquid crystal thermography (LCT) techniques have been used for multi-plane aerothermal measurements to elucidate the correlation of complex flow with thermal fields. Results indicate that the matrix emanates the corotating vortices, leading to spatially non-uniform secondary flows, including the emergence of Dean-type vortices at the downstream bend. In particular, the 4SC matrix promotes stronger vortex-driven mixing, yielding significant local and average heat transfer enhancement in the bend region. At Re = 10,000, the 4SC channel achieves a peak heat transfer augmentation of 133 % relative to a smooth baseline, while incurring only a slight increase in friction factor. Across all conditions, the 3SC and 4SC configurations deliver thermal performance factors (TPF) of up to 2.09 and 2.34, respectively. These findings support the potential of matrix cooling to deliver high thermal effectiveness in next-generation internal cooling applications.

矩阵冷却作为一种先进的燃气轮机内部冷却策略正受到越来越多的关注，它既提供了增强的机械完整性，又提供了优越的传热。然而，弯曲区域的气动热行为，特别是在基体的下游，仍然没有得到充分的探索。本研究对基质通道下游弯曲段的流动动力学和传热进行了详细的实验研究。在雷诺数（Re）为5000、7500和10000时，系统地研究了(i) 3-子通道（3SC）和（ii） 4-子通道（4SC）两种矩阵构型。高分辨率粒子图像测速（PIV）和液晶热成像（LCT）技术被用于多平面气动热测量，以阐明复杂流动与热场的关系。结果表明，该矩阵产生旋转涡，导致二次流在空间上不均匀，包括在下游弯道处出现迪恩型涡。特别是，4SC矩阵促进了更强的涡驱动混合，在弯曲区域产生显著的局部和平均传热增强。在Re = 10,000时，4SC通道相对于平滑基线实现了133%的峰值传热增加，而摩擦系数仅略有增加。在所有条件下，3SC和4SC配置的热性能系数（TPF）分别高达2.09和2.34。这些发现支持了基质冷却在下一代内部冷却应用中提供高热效率的潜力。

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引用次数: 0

Quantitative analysis of supercritical CO2 jet structure from Schlieren imaging in free and impinged configurations 从纹影成像中定量分析自由和冲击状态下超临界CO2射流结构

IF 3.3 2区工程技术 Q2 ENGINEERING, MECHANICAL

Experimental Thermal and Fluid Science

Pub Date : 2026-01-30 Epub Date: 2025-11-22 DOI: 10.1016/j.expthermflusci.2025.111661

Maha El Nahas , Thomas Pottier , Jean-Jacques Letourneau , Yann Landon

In recent years supercritical carbon dioxide (sCO

_{2}

) has emerged as a promising technology for machining assistance. Its contribution to the tool lifetime relies on both tribological and thermal actions on the control of the cutting zone. The present contribution proposes an experimental investigation of the flow features of a sCO

_{2}

jet. It intends to address primary data regarding the influence of the operating parameters on the shock structures and the flow characteristic (laminar–turbulent). It also intends to provide some explanations for the thermal behavior of such flow already observed in other published papers. This work addresses both free and impinged jets and investigates the influence of the impingement on the nature of the flow through Schlieren imaging and flow velocity estimation.

近年来，超临界二氧化碳（sCO2）已成为一种很有前途的机械加工辅助技术。它对刀具寿命的贡献取决于切削区控制的摩擦学和热作用。本文提出了一种二氧化硅射流流动特性的实验研究方法。它打算处理有关操作参数对激波结构和流动特性（层流-湍流）的影响的原始数据。本文还试图对其他已发表的论文中观察到的这种流动的热行为提供一些解释。这项工作涉及自由和撞击射流，并通过纹影成像和流速估计研究了撞击对流动性质的影响。

引用次数: 0