International Journal of Heat and Fluid Flow最新文献_第6页

A posteriori analysis of flame surface density modelling for combustion noise prediction in premixed flames 预混合火焰燃烧噪声预测火焰表面密度模型的后验分析

IF 2.6 3区工程技术 Q2 ENGINEERING, MECHANICAL

International Journal of Heat and Fluid Flow

Pub Date : 2025-12-15 DOI: 10.1016/j.ijheatfluidflow.2025.110204

Pavel Panek , Davy Brouzet , Mohsen Talei

The ability of large-eddy simulation (LES) to capture premixed flame acoustics is studied for a turbulent, premixed, round jet flame. Central finite differencing schemes are used with artificial damping. The flame surface density (FSD) approach is used as the combustion model for the reaction progress variable. The effects of combustion modelling and the spatial discretisation scheme order on the flame shape and the sound pressure level (SPL) spectra are examined. It is shown that the FSD approach does not correctly capture flame annihilation. This is where the progress variable gradient decreases as two flame surfaces approach each other. A significant impact of FSD modelling on the SPL is also observed. Comparing the SPL spectra obtained with FSD modelling with those obtained with single-step, Arrhenius-rate chemistry on a fine grid shows that the SPL is underestimated below

S t \approx 4

and overestimated above

S t \approx 4

, where

S t

is a non-dimensional frequency based on the jet diameter and mean centreline jet velocity known as the Strouhal number. Coarse grid simulations approximately match the fine grid results at frequencies up to

S t \approx 3

but overestimate the SPL even more strongly above this level. It is concluded that FSD modelling needs further adjustments to accurately capture combustion noise.

研究了大涡模拟（LES）对紊流、预混、圆形射流火焰的捕捉能力。中心有限差分格式采用人工阻尼。采用火焰表面密度法作为反应过程变量的燃烧模型。研究了燃烧模型和空间离散方案顺序对火焰形状和声压级（SPL）谱的影响。结果表明，FSD方法不能正确地捕捉火焰的湮灭。这是当两个火焰表面相互接近时，进度变量梯度减小的地方。FSD模型对SPL的显著影响也被观察到。将FSD模拟得到的SPL谱与单步arhenius -rate化学在精细网格上得到的SPL谱进行比较，发现SPL在St≈4以下被低估，而在St≈4以上被高估，其中St是基于射流直径和平均中线射流速度（称为Strouhal数）的无量纲频率。粗网格模拟在St≈3以下的频率与细网格模拟结果大致匹配，但在此水平以上，对声压级的高估更为强烈。结论是消防处模型需要进一步调整以准确捕捉燃烧噪声。

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引用次数: 0

CFD investigation of thermal management and flow behavior in an optimized air-cooled tail rotor propulsion system 优化风冷尾桨推进系统的热管理与流动特性CFD研究

IF 2.6 3区工程技术 Q2 ENGINEERING, MECHANICAL

International Journal of Heat and Fluid Flow

Pub Date : 2025-12-14 DOI: 10.1016/j.ijheatfluidflow.2025.110202

Hyowon Bang , Huichan Lee , Giyoung Park , Sungjae Kim , Seangwock Lee

As aerospace propulsion steadily transitions toward electrification, effectively dissipating heat in compact electric tail rotor motors has become a pressing design challenge. In this study, a high-fidelity computational fluid dynamics (CFD) framework is employed to investigate an air-cooled propulsion system specifically configured for helicopter tail rotor applications. Three passive geometric modifications are examined in detail: widening of lateral duct openings, introducing a 15° inclination to the duct sidewalls, and incorporating rotating blades along the central shaft. The optimized configuration demonstrated substantial thermal gains, reducing peak temperatures by 10.38% in the winding, 8.23% in the magnet, and 19.0% in the shaft. This enhancement was primarily attributed to enhanced airflow penetration, boundary-layer thinning, and the development of favorable secondary recirculation zones. Convective heat transfer performance was also elevated, with Nusselt numbers increasing by up to 11.6% across key components. Importantly, these thermal benefits were achieved while maintaining aerodynamic integrity, as the simulated thrust deviated by only 1.34% from experimental rig measurements. The results highlight how targeted, flow-physics-based passive design strategies can simultaneously improve cooling performance and preserve propulsion efficiency. This approach offers a scalable and integration-friendly pathway for next-generation electric rotorcraft requiring lightweight, thermally resilient tail rotor systems.

随着航空航天推进向电气化的稳步过渡，在紧凑型电动尾桨电机中有效散热已成为一个紧迫的设计挑战。在本研究中，采用高保真计算流体动力学（CFD）框架对直升机尾桨专用的气冷推进系统进行了研究。详细检查了三种被动几何修改：拓宽侧管道开口，向管道侧壁引入15°倾角，并沿中央轴合并旋转叶片。优化后的结构显示出显著的热增益，绕组的峰值温度降低了10.38%，磁体的峰值温度降低了8.23%，轴的峰值温度降低了19.0%。这种增强主要是由于气流穿透增强、边界层变薄以及有利的二次再循环区发展。对流换热性能也得到了提升，关键部件的努塞尔数增加了11.6%。重要的是，在保持气动完整性的同时，获得了这些热效益，因为模拟推力与实验装置测量值的偏差仅为1.34%。研究结果强调了有针对性的、基于流动物理的被动设计策略如何在提高冷却性能的同时保持推进效率。这种方法为需要轻型、热弹性尾桨系统的下一代电动旋翼飞机提供了一种可扩展且易于集成的途径。

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引用次数: 0

Effects of the upwind spanwise heterogeneous terrain on the wind resource distribution 逆风向非均质地形对风资源分布的影响

IF 2.6 3区工程技术 Q2 ENGINEERING, MECHANICAL

International Journal of Heat and Fluid Flow

Pub Date : 2025-12-14 DOI: 10.1016/j.ijheatfluidflow.2025.110182

Haosen H.A. Xu , Tianxiang Yu , Raúl Bayoán Cal , Xiaowei Zhu

Wind energy has become increasingly crucial among renewable energy resources, and as the prerequisite for effective wind energy utilization, accurate wind resource assessments are hence prominent. Topography significantly affects near-surface wind fields and is thus an essential factor to be considered for wind resource assessment. However, few studies have addressed the wind resource distribution downwind of spanwise-heterogeneous terrains, which are frequently encountered in both natural and urban environments. To fill this gap, large eddy simulations were performed to investigate wind distributions over a uniform terrain downwind of terrains featuring spanwise-alternating strips of low and high surface roughness, and the high roughness surface coverage ratio

λ

is varied from 12.5% to 100%. The analysis focuses on the wind speed within the turbine blades region, and two dominant mechanisms are identified: the rough-to-smooth transition (RST) and spanwise heterogeneity of momentum (SHM). The dominance of the two mechanisms depends strongly on

λ

, with RST dominating over SHM as

λ

increases. Moreover, RST initially increases the wind speed due to the growth of the internal boundary layer but leads to a decrease of wind speed further downwind as the internal boundary layer rearranges. SHM results from secondary flows induced by the heterogeneous terrain upwind, which decay downwind. As

λ

increases, secondary flow structures transition from asymmetric to symmetric patterns, and lower

λ

leads to asymmetric flows, sustaining momentum heterogeneity farther downwind. Hence, upwind spanwise heterogeneous terrains can significantly impact the wind speed distribution, and suggestions are made for wind farm planning based on the results.

风能在可再生能源中的地位越来越重要，准确的风能资源评价是有效利用风能的前提。地形对近地面风场影响显著，是风资源评价的重要因素。然而，对于在自然和城市环境中经常遇到的跨向异质地形顺风风资源分布，研究较少。为了填补这一空白，进行了大涡模拟，研究了均匀地形下的风分布，地形具有低表面粗糙度和高表面粗糙度沿展向交替带，高粗糙度表面覆盖率λ从12.5%变化到100%。分析了涡轮叶片区域内的风速，确定了两种主要机制：粗糙-平滑过渡（RST）和动量沿展向非均质性（SHM）。这两种机制的优势很大程度上取决于λ，随着λ的增加，RST的优势大于SHM。此外，由于内边界层的增长，RST最初会增加风速，但随着内边界层的重新排列，会导致进一步下风的风速降低。SHM是由上风向非均匀地形引起的二次流引起的，下风减弱。随着λ的增加，二次流结构从非对称模式转变为对称模式，较低的λ导致不对称流动，维持了下风更远的动量非均质性。因此，逆风向非均质地形对风速分布有显著影响，并根据研究结果对风电场规划提出建议。

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引用次数: 0

A comprehensive review of nucleate boiling fundamentals applied to thin film annular flow 核沸腾基本原理在薄膜环流中的应用综述

IF 2.6 3区工程技术 Q2 ENGINEERING, MECHANICAL

International Journal of Heat and Fluid Flow

Pub Date : 2025-12-14 DOI: 10.1016/j.ijheatfluidflow.2025.110199

Joseph Farrell , Evan T. Hurlburt , Arganthaël Berson , Allison Mahvi

Nucleate boiling in thin film annular flow is a complex phenomenon influenced by a variety of heat transfer mechanisms. While the fundamentals are rooted in the comparatively well-understood fields of pool and flow boiling, thin film flow boiling introduces additional challenges that make the heat transfer behavior hard to predict. Specifically, the relative importance of the heat transfer mechanisms controlling nucleate boiling in thin annular films and their roles in flow regime transitions remains inadequately understood. In light of this, the foundational aspects of nucleate boiling and the relationship between flow parameters – such as liquid film thickness, system pressure, surface tension, channel geometry, mass flow rate, and applied heat flux – and the intensity of nucleate boiling in thin annular films are analyzed. The importance of these parameters is demonstrated through the presentation of multiple correlations, with a critical examination of the limitations inherent in correlation-based modeling. Additionally, recent research has identified disturbance waves as a significant factor in enhancing bubble nucleation, yet the underlying mechanisms driving this phenomenon remain undefined. Therefore, the insights and deficiencies of three theories seeking to explain wave-based nucleation are extensively considered. This research aims to introduce and categorize the wide breadth of literature regarding thin film annular flow nucleate boiling to identify gaps in understanding and facilitate future physics-based modeling efforts.

薄膜环流中的核沸腾是一个受多种传热机制影响的复杂现象。虽然基本原理植根于相对较好理解的池沸腾和流动沸腾领域，但薄膜流动沸腾引入了额外的挑战，使传热行为难以预测。具体来说，控制环状薄膜中核沸腾的传热机制的相对重要性及其在流态转变中的作用仍然没有得到充分的认识。在此基础上，分析了液膜厚度、系统压力、表面张力、通道几何形状、质量流量、外加热流密度等流动参数与薄环形膜中成核沸腾强度的关系。这些参数的重要性通过多个相关性的呈现来证明，并对基于相关性的建模固有的局限性进行了严格的检查。此外，最近的研究已经确定扰动波是增强气泡成核的重要因素，但驱动这一现象的潜在机制仍未明确。因此，寻求解释波基成核的三个理论的见解和不足被广泛考虑。本研究旨在介绍和分类关于薄膜环流核沸腾的广泛文献，以确定理解上的差距，并促进未来基于物理的建模工作。

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引用次数: 0

An autoencoder-based bi-fidelity method utilising frozen latent spaces. Application to flow past a confined cylinder 一种基于自编码器的双保真度方法，利用冻结隐空间。用于流过密闭圆筒

IF 2.6 3区工程技术 Q2 ENGINEERING, MECHANICAL

International Journal of Heat and Fluid Flow

Pub Date : 2025-12-12 DOI: 10.1016/j.ijheatfluidflow.2025.110192

W. Lu , W.K. Lam , T. Zahtila

This study presents a simple autoencoder-based bi-fidelity method, where the latent space is constrained to be invariant between both low- and high-fidelity datasets. The method is applied to the flow past a cylinder confined in a duct, where model fidelity is governed by computational model resolution. Significant cost savings are observed without significant compromise to approximation accuracy. The influence of several hyperparameters are considered including: latent space dimension, sample number and distribution. A method of generating synthetic solutions is also explored. This is done by performing regression on the common latent space of low- and high-fidelity models, which is then passed through the high-fidelity decoder. As a large number of samples are available from the low-fidelity model, significant improvements are observed compared with the traditional method of interpolating only high-fidelity data.

本研究提出了一种简单的基于自编码器的双保真度方法，其中潜在空间在低保真度和高保真度数据集之间被约束为不变。该方法适用于流通过一个圆柱体限制在一个管道，其中模型保真度是由计算模型的分辨率。在不影响近似精度的情况下，显著节省了成本。考虑了几个超参数的影响，包括潜在空间维数、样本数量和分布。本文还探讨了一种生成合成解的方法。这是通过对低保真度和高保真度模型的共同潜在空间执行回归来完成的，然后将其通过高保真度解码器。由于低保真度模型中有大量的样本，与传统的只插值高保真度数据的方法相比，有了显著的改进。

引用次数: 0

Preliminary study on the dynamic equilibrium process of supercritical region CO2 fluid by phase field method 用相场法初步研究超临界区CO2流体的动态平衡过程

IF 2.6 3区工程技术 Q2 ENGINEERING, MECHANICAL

International Journal of Heat and Fluid Flow

Pub Date : 2025-12-11 DOI: 10.1016/j.ijheatfluidflow.2025.110189

Huan Liu , Pavel Skripov , Lin Chen

The supercritical fluid region is generally considered a complex phase region, which has a lot on the thermodynamic transitions and fluid transport behaviors of a system. The present study introduces a phase-field method using density as the order parameter, which is combined with a free energy minimization technique to predict the dynamic responses of supercritical CO₂ under parameter equilibrium procedures. During this phase, field simulation analysis, cases from the close-to-critical region, liquid region, and low-density fluid region have been examined, which procedures then show a system equilibrium stage from ‘quasi-uniform’ state to an ‘overall equilibrium’ state. The simulation process follows a continuous and gradual change in macroscopic properties rather than the abrupt transition observed in the conventional phase change process. By statistically tracking the temporal evolution of ‘pseudo-liquid regions’, the local non-uniformities emergence process during the formation of supercritical phases has been revealed, which in turn gives the dynamic development of spatial heterogeneity. The extrema of density fluctuations form ridge lines near the pseudo-critical line, with a maximum spatial fluctuation error of 0.06% compared to the pseudo-critical line. The boundary identified with intense density fluctuations resembles the dynamic transition across the pseudo-critical triangle.

超临界流体区通常被认为是一个复杂的相区，它对系统的热力学转变和流体输运行为有很大的影响。本文介绍了一种以密度为序参量的相场法，结合自由能最小化技术来预测超临界CO2在参数平衡过程中的动态响应。在此阶段，现场模拟分析了近临界区域、液体区域和低密度流体区域的情况，这些过程显示了系统从“准均匀”状态到“整体平衡”状态的平衡阶段。模拟过程遵循宏观性质的连续渐进变化，而不是传统相变过程中观察到的突然转变。通过统计跟踪“伪液体区域”的时间演变，揭示了超临界相形成过程中局部非均匀性的出现过程，从而给出了空间异质性的动态发展。密度波动极值在拟临界线附近形成脊线，与拟临界线相比，最大空间波动误差为0.06%。具有强烈密度波动的边界类似于跨越伪临界三角形的动态过渡。

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引用次数: 0

Mathematical modelling and heat-mass transport analysis of a bioconvective Casson hybrid nanofluid in a stenosed artery 狭窄动脉中生物对流卡森混合纳米流体的数学建模和热质传递分析

IF 2.6 3区工程技术 Q2 ENGINEERING, MECHANICAL

International Journal of Heat and Fluid Flow

Pub Date : 2025-12-10 DOI: 10.1016/j.ijheatfluidflow.2025.110190

Anthuvan Ezhilarasi P., Dhivya Mohanavel

Arterial stenosis causes the arteries to narrow, a change that can significantly impact blood flow. Identifying the conditions related to arterial blockage is crucial for prompt diagnosis and treatment. Keeping this fact in mind, the purpose of this study is to analyse the heat and mass transfer properties of a Casson hybrid blood flow in a constricted artery inhabited by oxytactic microorganisms, and also by employing the Arrhenius energy. The mathematical assessment of copper and titanium oxide in the stenosis region, where blood circulates, considers temperature-dependent viscosity and thermal conductivity. The hybrid (Cu/TiO

_{2}

) nanoparticles used in the bloodstream synergise to enhance heat and mass transfer, offers antithrombotic and antimicrobial benefits which promote better vascular health and prevent infection. The governing coupled partial differential equations are converted into a system of nonlinear ordinary differential equations via the similarity transformation technique, and the resulting ODE is then numerically solved using the MATLAB solver. The influences of various factors, including variable viscosity, variable thermal conductivity, activation energy, chemical reaction, bioconvection Schmidt number, and Peclet number, have been examined in equations for velocity, temperature, concentration, and microorganisms. The primary findings indicate that varying the viscosity parameter slows the flow rate, whereas raising the values of thermal conductivity parameter makes heat transmission more reliable. Additionally, the reduction in motile density profiles was attributed to both Lewis number and bioconvection Schmidt number. Furthermore, this study was compared to previous results, showing a high degree of correspondence. The sensitivity analysis used in this model examines the impact of different factors on the effectiveness of convective and diffusive transport processes in mass transfer. This research can improve arterial disease diagnostic techniques by simulating intricate blood flow scenarios.

动脉狭窄导致动脉狭窄，这种变化会显著影响血液流动。确定与动脉阻塞相关的条件对于及时诊断和治疗至关重要。考虑到这一事实，本研究的目的是分析卡森杂交血液在有氧合微生物居住的收缩动脉中的传热和传质特性，并利用阿伦尼乌斯能量。在血液循环的狭窄区域，铜和氧化钛的数学评估考虑了温度依赖性粘度和导热性。混合（Cu/TiO2）纳米颗粒用于血液协同增强热量和质量传递，提供抗血栓和抗菌的好处，促进更好的血管健康和预防感染。利用相似变换技术将控制耦合偏微分方程转化为非线性常微分方程组，利用MATLAB求解器对得到的微分方程进行数值求解。各种因素的影响，包括变粘度、变导热系数、活化能、化学反应、生物对流施密特数和佩克莱数，已经在速度、温度、浓度和微生物的方程中进行了检验。初步研究结果表明，改变粘度参数会减慢流速，而提高导热系数参数使传热更可靠。此外，运动密度曲线的减小归因于Lewis数和生物对流Schmidt数。此外，本研究与以往的结果进行了比较，显示出高度的一致性。该模型中使用的敏感性分析考察了不同因素对传质过程中对流和扩散传递过程有效性的影响。这项研究可以通过模拟复杂的血流场景来改善动脉疾病的诊断技术。

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引用次数: 0

Impact of cylinder diameter and spacing on fluid flow, forces, and heat transfer in tandem cylinder configuration 圆柱直径和间距对串联式圆柱结构中流体流动、力和传热的影响

IF 2.6 3区工程技术 Q2 ENGINEERING, MECHANICAL

International Journal of Heat and Fluid Flow

Pub Date : 2025-12-10 DOI: 10.1016/j.ijheatfluidflow.2025.110178

Md. Mahbub Alam , Zia Ullah , Hongjun Zhu , Chunning Ji , Md. Islam , Mostafa Zeinoddini

This study numerically investigates the fluid flow, aerodynamic forces, and heat transfer characteristics around a circular cylinder (diameter D) positioned in the wake of another cylinder (diameter d), with varying diameter ratios d/D (= 0.4, 0.6, 0.8, and 1.0) and inter-cylinder spacing ratios L* (= L/D = 1.2 –5.0). Significant effects of d/D and L* are identified on forces, heat transfer, and fluid dynamics at Re_D = 200. For a given L*, time-mean drag, fluctuating lift and drag, and Nusselt number all are generally smaller for larger d/D, with the time-mean drag force even becoming negative for d/D = 1.0. In the reattachment flow regime, the time-mean drag and Nusselt number decrease with increasing L* for smaller d/D = 0.4 and 0.6 but increase for larger d/D = 0.8 and 1.0. In the coshedding flow regime, the Nusselt number and forces increase with L*, regardless of d/D. The critical L* separating the reattachment and coshedding flows increases with increasing d/D from 0.4 to 0.8 before declining from d/D = 0.8 to 1.0. Streamwise velocity fields and local Nusselt number distributions on the cylinder surface are analyzed to explain the observed heat transfer phenomena. Local heat transfer is maximal on the front surface of the cylinder, corresponding to the inflection point on the near-surface velocity profile.

本文通过数值模拟研究了不同直径比D /D（= 0.4、0.6、0.8和1.0）和缸间间距比L* (= L/D = 1.2 -5.0)下，一个圆柱体（直径D）与另一个圆柱体（直径D）的尾迹之间的流体流动、气动力和传热特性。在ReD = 200时，确定了d/ d和L*对力、传热和流体动力学的显著影响。对于给定的L*，当d/ d较大时，时间平均阻力、波动升力和阻力以及努塞尔数一般都较小，当d/ d = 1.0时，时间平均阻力甚至变为负值。当d/ d = 0.4和0.6时，时间平均阻力和Nusselt数随L*的增大而减小，当d/ d = 0.8和1.0时，时间平均阻力和Nusselt数随L*的增大而增大。在共脱落流态中，努塞尔数和力随L*的增加而增加，与d/ d无关。分离重附流和共脱落流的临界L*随着d/ d的增加从0.4增大到0.8，然后从d/ d = 0.8减小到1.0。分析了圆柱表面的流向速度场和局部努塞尔数分布来解释观察到的换热现象。局部换热在柱体前表面最大，与近表面速度剖面的拐点相对应。

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引用次数: 0

Design and performance optimization of liquid immersion cooling system for prismatic lithium-ion battery modules 棱镜型锂离子电池模块液浸冷却系统设计及性能优化

IF 2.6 3区工程技术 Q2 ENGINEERING, MECHANICAL

International Journal of Heat and Fluid Flow

Pub Date : 2025-12-08 DOI: 10.1016/j.ijheatfluidflow.2025.110181

Luyao Zhao, Jiafeng Wang, Minxue Zheng, Mingyi Chen

Optimal thermal regulation in battery modules is critical for maintaining the efficient and reliable operation of battery packs. This study designed an active immersion cooling system for prismatic lithium-ion battery modules, demonstrating maximum temperature reductions of 34 % and 47.7 % relative to static submersion cooling and free convection methods, respectively. The impacts of coolant flow rate, flow direction, and module arrangement patterns on forced-flow immersion cooling performance were numerically investigated. Results indicate that parallel battery arrangements show superior cooling performance compared to staggered configurations. Among the five flow patterns (top to bottom, bottom to top, top to top, bottom to bottom, and center to center), the top to bottom layout exhibits the optimal cooling efficiency. As the inlet flow rate increases, both the maximum battery temperature and the temperature difference across the battery pack first drop sharply and then slowly after the flow rate reaches 0.023 kg/s. Power consumption demonstrates a positive relationship with inlet velocity, whereas the cooling index shows an inverse relationship. As the horizontal spacing between batteries varies from 1 to 6 mm, the maximum temperature of the battery and temperature difference show a “U” shaped trend, the power consumption decreases monotonically, while the cooling index shows a “И” shaped variation trend. Similarly, with the increase of longitudinal distance between batteries, Both the peak battery temperature and temperature differential present a “U” shaped variation trend, and the power dissipation decreases monotonically. Conversely, the cooling index increases monotonously. Finally, a 4-mm horizontal and 5-mm longitudinal spacing were identified as the optimal configuration. This study addressed both operational safety and thermal management efficiency for prismatic lithium-ion batteries, and established design guidelines for high-performance immersion cooling systems.

电池模块的最佳热调节对于保持电池组的高效可靠运行至关重要。该研究为棱柱形锂离子电池模块设计了一种主动浸没冷却系统，与静态浸没冷却和自由对流冷却方法相比，最大温度分别降低了34%和47.7%。研究了冷却剂流量、流动方向和模块布置方式对强制浸没冷却性能的影响。结果表明，与交错配置相比，并联电池配置具有更好的冷却性能。在5种流动模式（从上到下、从下到上、从上到上、从下到下、从中心到中心）中，从上到下的布局具有最佳的冷却效率。随着进口流量的增加，在流量达到0.023 kg/s后，电池最高温度和电池组温差均先急剧下降，然后缓慢下降。功率消耗与进口速度呈正相关，而冷却指数呈反比关系。当电池水平间距在1 ~ 6mm范围内变化时，电池最高温度和温差呈“U”型变化趋势，功耗单调下降，冷却指数呈“И”型变化趋势。同样，随着电池间纵向距离的增加，电池峰值温度和温差均呈“U”型变化趋势，且功耗单调减小。反之，冷却指数单调增加。最后，确定水平间距为4 mm，纵向间距为5 mm为最优配置。该研究解决了棱柱形锂离子电池的操作安全性和热管理效率，并建立了高性能浸入式冷却系统的设计指南。

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引用次数: 0

Comparative study on heat extraction performance and economic feasibility between medium-deep coaxial and U-type ground heat exchangers 中深同轴与u型地热交换器排热性能及经济可行性对比研究

IF 2.6 3区工程技术 Q2 ENGINEERING, MECHANICAL

International Journal of Heat and Fluid Flow

Pub Date : 2025-12-06 DOI: 10.1016/j.ijheatfluidflow.2025.110170

Pengtao Wang , Rui Liang , Shimin Wang , Junyu Feng , Jie Zhang , Shengshan Bi

This study utilizes a geothermal heating project located in Xi’an as a case study, developing full-scale numerical models for medium-deep coaxial borehole heat exchangers (DCBHE) and medium-deep U-type borehole heat exchangers (DUBHE) at equivalent depths. Through extensive heat transfer simulations conducted over five cycles, the research provides a comprehensive comparison of the heat extraction efficiency and economic viability of the two types of ground heat exchangers. This comparison employs a ratio method that accounts for pump energy losses, the levelized cost of heat (LCOH), and net present value (NPV) metrics. The findings indicate that the heat exchange per unit length for DCBHE and DUBHE ranges from 123.1 to 149.5 W/m and 93.9 to 170.71 W/m, respectively, with a critical flow rate of 7.21 kg/s. When incorporating pump power consumption, the critical flow rate is determined to be 6.62 kg/s, which corresponds to a comprehensive heat exchange per unit length of 127.7 W/m. Beyond this flow rate, the comprehensive heat transfer performance of DUBHE surpasses that of DCBHE. Therefore, this study divides the heat extraction zones into low-flow zones and high-flow zones based on the critical flow rate of 6.62 kg/s, providing a qualitative identification basis for selecting appropriate flow rate conditions for different types of heat exchangers. The economic analysis reveals that at the critical flow rate, the cost per unit of heat extraction for DCBHE exceeds that of DUBHE, and as the heat extraction duration increases, the NPV of DUBHE becomes more favorable compared to DCBHE. Consequently, DUBHE is determined to be more economically viable than DCBHE.

本研究以西安某地热供热项目为例，建立了等效深度的中深同轴井眼热交换器（DCBHE）和中深u型井眼热交换器（DUBHE）全尺寸数值模型。通过对5个循环进行的广泛的传热模拟，研究提供了两种类型的地面热交换器的热提取效率和经济可行性的综合比较。这种比较采用了一种比率法，该方法考虑了泵的能量损失、热量平准化成本（LCOH）和净现值（NPV）指标。结果表明：DCBHE和DUBHE的单位长度换热范围分别为123.1 ~ 149.5 W/m和93.9 ~ 170.71 W/m，临界流量为7.21 kg/s；考虑泵功率消耗，确定临界流量为6.62 kg/s，单位长度综合换热127.7 W/m。在此流量之外，DUBHE的综合换热性能优于DCBHE。因此，本研究以6.62 kg/s的临界流量为基础，将抽热区划分为低流量区和高流量区，为不同类型换热器选择合适的流量条件提供定性识别依据。经济分析表明，在临界流量下，DCBHE的单位抽热成本高于DUBHE，且随着抽热时间的增加，DUBHE的净现值优于DCBHE。因此，DUBHE在经济上比DCBHE更可行。

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