International Journal of Heat and Mass Transfer最新文献_第4页

Linear instability in Taylor–Couette flows with non-ideal fluids 非理想流体Taylor-Couette流的线性不稳定性

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-12 DOI: 10.1016/j.ijheatmasstransfer.2026.128346

Congren Zheng , Xuhui Liu , Tianyan Liu , Youchuang Chao , Zijing Ding

We present a systematic linear stability analysis of Taylor–Couette flows with non-ideal fluids, taking carbon dioxide near its critical point as a representative working fluid. By exploring different thermodynamic states (subcritical, transcritical, and supercritical), rotational configurations (single-, co-, and counter-rotation), and multiple equations of state, we reveal how thermodynamic non-ideality, compressibility, and rotational shear synergistically impact the flow stability. We show that the subcritical state is the most unstable state under counter-rotation, the transcritical state is the most complex state, and the supercritical state generally suppresses instability. However, compressibility exhibits state-dependent behavior: instability is enhanced with increasing fluid compressibility

P r E c

in the subcritical state but varies non-monotonically in the transcritical state. Significant discrepancies are found between real-fluid and ideal-gas predictions, particularly near the critical point, underscoring the necessity of an accurate thermodynamic model. Furthermore, modal analysis demonstrates that disturbances with azimuthal wavenumbers

n = 0 - 2

typically dominate, although higher-order modes may prevail under strong counter-rotation. Finally, by performing the energy budget analysis, we identify that the shear production is the primary energy source, while non-ideality modifies energy transfer via coupling thermal and velocity perturbations. Our findings may advance the fundamental understanding of Taylor–Couette flows with non-ideal fluids and provide insights for predicting and controlling the stability of real-fluid systems that operate near critical conditions.

本文以临界点附近的二氧化碳为代表工质，对非理想流体的Taylor-Couette流动进行了系统的线性稳定性分析。通过探索不同的热力学状态（亚临界、跨临界和超临界）、旋转构型（单旋转、共旋转和反旋转）和多个状态方程，我们揭示了热力学非理想性、可压缩性和旋转剪切如何协同影响流动稳定性。我们证明了亚临界状态是反旋转下最不稳定的状态，跨临界状态是最复杂的状态，超临界状态通常抑制不稳定。然而，可压缩性表现出状态依赖行为：在亚临界状态下，不稳定性随着流体可压缩性PrEc的增加而增强，但在跨临界状态下，不稳定性呈非单调变化。在实际流体和理想气体预测之间发现了显著的差异，特别是在临界点附近，强调了精确热力学模型的必要性。此外，模态分析表明，方位角波数n=0 ~ 2的扰动通常占主导地位，尽管高阶模态可能在强反旋转下占上风。最后，通过进行能量收支分析，我们确定剪切生产是主要的能量来源，而非理想性通过耦合热和速度扰动改变能量传递。我们的发现可能会促进对非理想流体的Taylor-Couette流动的基本理解，并为预测和控制在临界条件下运行的实际流体系统的稳定性提供见解。

{"title":"Linear instability in Taylor–Couette flows with non-ideal fluids","authors":"Congren Zheng , Xuhui Liu , Tianyan Liu , Youchuang Chao , Zijing Ding","doi":"10.1016/j.ijheatmasstransfer.2026.128346","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128346","url":null,"abstract":"<div><div>We present a systematic linear stability analysis of Taylor–Couette flows with non-ideal fluids, taking carbon dioxide near its critical point as a representative working fluid. By exploring different thermodynamic states (subcritical, transcritical, and supercritical), rotational configurations (single-, co-, and counter-rotation), and multiple equations of state, we reveal how thermodynamic non-ideality, compressibility, and rotational shear synergistically impact the flow stability. We show that the subcritical state is the most unstable state under counter-rotation, the transcritical state is the most complex state, and the supercritical state generally suppresses instability. However, compressibility exhibits state-dependent behavior: instability is enhanced with increasing fluid compressibility <span><math><mrow><mi>P</mi><mi>r</mi><mi>E</mi><mi>c</mi></mrow></math></span> in the subcritical state but varies non-monotonically in the transcritical state. Significant discrepancies are found between real-fluid and ideal-gas predictions, particularly near the critical point, underscoring the necessity of an accurate thermodynamic model. Furthermore, modal analysis demonstrates that disturbances with azimuthal wavenumbers <span><math><mrow><mi>n</mi><mo>=</mo><mn>0</mn><mo>−</mo><mn>2</mn></mrow></math></span> typically dominate, although higher-order modes may prevail under strong counter-rotation. Finally, by performing the energy budget analysis, we identify that the shear production is the primary energy source, while non-ideality modifies energy transfer via coupling thermal and velocity perturbations. Our findings may advance the fundamental understanding of Taylor–Couette flows with non-ideal fluids and provide insights for predicting and controlling the stability of real-fluid systems that operate near critical conditions.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"259 ","pages":"Article 128346"},"PeriodicalIF":5.8,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974944","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Inverse optimization of solidification via the Stefan problem in continuous steel slab casting 基于Stefan问题的连铸板坯凝固反优化

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-10 DOI: 10.1016/j.ijheatmasstransfer.2026.128363

Ali Pourfathi

This study establishes a novel theoretical and computational framework for the inverse design of cooling variables in continuous steel slab casting, with a focused investigation into a previously overlooked aspect: the systematic influence of design-variable selection on the optimization outcome. The problem is formulated as an inverse heat-transfer problem, constrained by a target solidification front derived from a second-order Stefan approximation. This front inherently embeds critical metallurgical constraints — the Niyama criterion for porosity and a breakout threshold — to ensure defect-aware solidification control.

Two distinct inverse strategies are formulated and compared: one optimizes heat flux, superheat, and casting velocity (OPQ), while the other optimizes heat-transfer coefficient, spray water temperature, and casting velocity (OPH). Both are solved using a projected steepest descent algorithm. A rigorous comparative analysis reveals that the fundamental choice of design variables dictates numerical performance and physical interpretation. The OPH strategy demonstrates superior convergence efficiency and reliability, better captures radiative heat transfer, and yields a lower defect risk profile. In contrast, the OPQ strategy reduces model nonlinearity and yields a convection-dominated cooling profile.

The proposed in silico framework presents a mathematically grounded methodology for inverse solidification design. It provides a systematic comparative study of variable selection within the proposed framework and offers a robust offline design capability for initial process parameterization, effectively decoupling the complex design phase from reliance on extensive experimental trial-and-error procedures.

本研究为连铸钢坯冷却变量的反设计建立了一个新的理论和计算框架，重点研究了一个以前被忽视的方面：设计变量选择对优化结果的系统影响。该问题被表述为一个由二阶Stefan近似导出的目标凝固前沿约束的反传热问题。这一前沿固有地嵌入了关键的冶金约束- Niyama孔隙率准则和破裂阈值-以确保缺陷感知的凝固控制。制定并比较了两种不同的反策略：一种优化热流密度、过热度和铸造速度（OPQ），而另一种优化传热系数、喷雾水温和铸造速度（OPH）。两者都使用投影最陡下降算法求解。一项严格的比较分析表明，设计变量的基本选择决定了数值性能和物理解释。OPH策略展示了卓越的收敛效率和可靠性，更好地捕获辐射传热，并产生更低的缺陷风险。相比之下，OPQ策略减少了模型非线性并产生对流主导的冷却剖面。提出的硅框架提出了一种基于数学的反凝固设计方法。它在提出的框架内提供了变量选择的系统比较研究，并为初始过程参数化提供了强大的离线设计能力，有效地将复杂的设计阶段从依赖广泛的实验试错过程中分离出来。

{"title":"Inverse optimization of solidification via the Stefan problem in continuous steel slab casting","authors":"Ali Pourfathi","doi":"10.1016/j.ijheatmasstransfer.2026.128363","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128363","url":null,"abstract":"<div><div>This study establishes a novel theoretical and computational framework for the inverse design of cooling variables in continuous steel slab casting, with a focused investigation into a previously overlooked aspect: the systematic influence of design-variable selection on the optimization outcome. The problem is formulated as an inverse heat-transfer problem, constrained by a target solidification front derived from a second-order Stefan approximation. This front inherently embeds critical metallurgical constraints — the Niyama criterion for porosity and a breakout threshold — to ensure defect-aware solidification control.</div><div>Two distinct inverse strategies are formulated and compared: one optimizes heat flux, superheat, and casting velocity (OPQ), while the other optimizes heat-transfer coefficient, spray water temperature, and casting velocity (OPH). Both are solved using a projected steepest descent algorithm. A rigorous comparative analysis reveals that the fundamental choice of design variables dictates numerical performance and physical interpretation. The OPH strategy demonstrates superior convergence efficiency and reliability, better captures radiative heat transfer, and yields a lower defect risk profile. In contrast, the OPQ strategy reduces model nonlinearity and yields a convection-dominated cooling profile.</div><div>The proposed <em>in silico</em> framework presents a mathematically grounded methodology for inverse solidification design. It provides a systematic comparative study of variable selection within the proposed framework and offers a robust offline design capability for initial process parameterization, effectively decoupling the complex design phase from reliance on extensive experimental trial-and-error procedures.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"259 ","pages":"Article 128363"},"PeriodicalIF":5.8,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multi-scale topology optimization of porous heat sinks with voided lattice structure using a two-layer Darcy–Forchheimer model 基于双层Darcy-Forchheimer模型的多孔多孔晶格结构散热器多尺度拓扑优化

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-10 DOI: 10.1016/j.ijheatmasstransfer.2025.128324

Tatsuki Saito , Yuto Kikuchi , Kuniharu Ushijima , Kentaro Yaji

This study presents a topology optimization framework for the design of water-cooled heat sinks that incorporate voided lattice structures, formulated using a two-layer Darcy–Forchheimer model. Conventional porous heat sinks often suffer from excessive pressure drop due to their intricate geometry, which limits their practical applicability. To address this issue, the proposed method introduces an explicit representation of both void and porous regions, together with graded lattice density, within a multi-material optimization framework. The two-layer Darcy–Forchheimer model enables efficient reduced-order simulations, allowing direct consideration of the heterogeneous porous-void distribution during the optimization process. The optimized designs are reconstructed into full-scale lattice geometries and validated through coupled thermo-fluid finite element analyses under fixed pressure-drop conditions. The results demonstrate that voided lattice configurations significantly outperform conventional plate-fin and uniform lattice heat sinks, achieving approximately 20%–30% higher maximum Nusselt numbers while maintaining lower pressure losses.

本研究提出了一种用于水冷散热器设计的拓扑优化框架，该框架采用了两层Darcy-Forchheimer模型。传统多孔散热片由于其复杂的几何结构，往往存在过大的压降，限制了其实际应用。为了解决这个问题，所提出的方法在多材料优化框架中引入了空洞和多孔区域的显式表示，以及梯度晶格密度。双层Darcy-Forchheimer模型实现了高效的降阶模拟，允许在优化过程中直接考虑非均质孔隙分布。在固定压降条件下，将优化设计重构为全尺寸晶格几何，并通过热-流体耦合有限元分析进行验证。结果表明，空心晶格结构明显优于传统的板翅式和均匀晶格散热器，在保持较低压力损失的同时，最大努塞尔数提高了约20%-30%。

{"title":"Multi-scale topology optimization of porous heat sinks with voided lattice structure using a two-layer Darcy–Forchheimer model","authors":"Tatsuki Saito , Yuto Kikuchi , Kuniharu Ushijima , Kentaro Yaji","doi":"10.1016/j.ijheatmasstransfer.2025.128324","DOIUrl":"10.1016/j.ijheatmasstransfer.2025.128324","url":null,"abstract":"<div><div>This study presents a topology optimization framework for the design of water-cooled heat sinks that incorporate voided lattice structures, formulated using a two-layer Darcy–Forchheimer model. Conventional porous heat sinks often suffer from excessive pressure drop due to their intricate geometry, which limits their practical applicability. To address this issue, the proposed method introduces an explicit representation of both void and porous regions, together with graded lattice density, within a multi-material optimization framework. The two-layer Darcy–Forchheimer model enables efficient reduced-order simulations, allowing direct consideration of the heterogeneous porous-void distribution during the optimization process. The optimized designs are reconstructed into full-scale lattice geometries and validated through coupled thermo-fluid finite element analyses under fixed pressure-drop conditions. The results demonstrate that voided lattice configurations significantly outperform conventional plate-fin and uniform lattice heat sinks, achieving approximately 20%–30% higher maximum Nusselt numbers while maintaining lower pressure losses.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"259 ","pages":"Article 128324"},"PeriodicalIF":5.8,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974940","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Viscous fingering with phase-changing (condensing) fluid displacement in radial Hele-Shaw cell 径向Hele-Shaw单元中具有相变（冷凝）流体位移的粘性指进

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-10 DOI: 10.1016/j.ijheatmasstransfer.2026.128331

Pooja Singh, Sourav Mondal

We focus on the immiscible displacement within a radial Hele-Shaw cell using a phase-changing medium. The high-viscosity oil is displaced by methanol vapour, along with its condensate. The condensed methanol liquid migrates toward the fingertip, exerting dominant control over the flow dynamics. The coexistence of vapour and liquid in the displacing phase induces anisotropy and heterogeneity in the viscous fingering pattern, markedly distinctive from the classical observations in Hele-Shaw cell experiments and exhibits non-intuitive pattern formations.

The study explores displacement in porous media where a high-viscosity cold fluid is replaced by a low-viscosity hot fluid (vapour liquid mixture). Thermal front movement is impeded due to heat transfer between the fluids as well as the large time scale of thermal diffusion to the other side of the quartz plate, causing the thermal front to lag behind the fluid front. Initially, momentum diffusion governs heat transfer, followed by thermal diffusion dominance. Interfacial oscillations induced by the Marangoni effect stemming from temperature-induced interfacial tension gradients, are observed. Numerical simulations of the multiphase transport process involving heat transfer, reveal non-trivial variations in the viscous fingering pattern concerning influential parameters such as the surface tension and fluid volume fraction.

本文采用相变介质研究了径向Hele-Shaw槽内的非混相位移。高粘度油被甲醇蒸气及其冷凝物取代。浓缩的甲醇液体向指尖迁移，对流动动力学施加主导控制。蒸汽和液体在置换相中的共存导致了黏性指指模式的各向异性和非均质性，这与Hele-Shaw细胞实验中的经典观测结果明显不同，并表现出非直观的模式形成。该研究探讨了多孔介质中高粘度冷流体被低粘度热流体（汽液混合物）取代的位移。由于流体之间的传热以及热扩散到石英板另一侧的大时间尺度，热锋的运动受到阻碍，导致热锋落后于流体锋。最初，动量扩散主导传热，其次是热扩散主导。观察到由温度引起的界面张力梯度引起的马兰戈尼效应引起的界面振荡。对涉及热传递的多相输运过程进行了数值模拟，揭示了黏性指进模式在影响表面张力和流体体积分数等参数方面的重要变化。

{"title":"Viscous fingering with phase-changing (condensing) fluid displacement in radial Hele-Shaw cell","authors":"Pooja Singh, Sourav Mondal","doi":"10.1016/j.ijheatmasstransfer.2026.128331","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128331","url":null,"abstract":"<div><div>We focus on the immiscible displacement within a radial Hele-Shaw cell using a phase-changing medium. The high-viscosity oil is displaced by methanol vapour, along with its condensate. The condensed methanol liquid migrates toward the fingertip, exerting dominant control over the flow dynamics. The coexistence of vapour and liquid in the displacing phase induces anisotropy and heterogeneity in the viscous fingering pattern, markedly distinctive from the classical observations in Hele-Shaw cell experiments and exhibits non-intuitive pattern formations.</div><div>The study explores displacement in porous media where a high-viscosity cold fluid is replaced by a low-viscosity hot fluid (vapour liquid mixture). Thermal front movement is impeded due to heat transfer between the fluids as well as the large time scale of thermal diffusion to the other side of the quartz plate, causing the thermal front to lag behind the fluid front. Initially, momentum diffusion governs heat transfer, followed by thermal diffusion dominance. Interfacial oscillations induced by the Marangoni effect stemming from temperature-induced interfacial tension gradients, are observed. Numerical simulations of the multiphase transport process involving heat transfer, reveal non-trivial variations in the viscous fingering pattern concerning influential parameters such as the surface tension and fluid volume fraction.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"259 ","pages":"Article 128331"},"PeriodicalIF":5.8,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

A comparative study on the effects of external and internal dry cooling zones on the performance of hybrid natural draft cooling towers 外冷区与内冷区对混合式自然通风冷却塔性能影响的比较研究

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-10 DOI: 10.1016/j.ijheatmasstransfer.2026.128354

Weipeng Deng , Zhufeng Lin , Huinan Yang , Fengzhong Sun , Huaqiang Chu

Due to the lack of quantitative evaluation methods for plumes, the design of plume control for large wet cooling towers still faces significant challenges. This study uses the outlet surface of cooling towers as the reference and proposes methods for calculating the plume area and the mass flow rate of the plume. Furthermore, a comparative analysis is conducted on the impact of internal (IN_DCZ) and external (EX_DCZ) dry cooling zones on the performance of hybrid cooling towers. Under wind conditions, the performance of IN_DCZ is better than that of EX_DCZ. Compared to EX_DCZ, the outlet water temperature of IN_DCZ reduces by 0.4 °C, the water-saving rate of IN_DCZ increases by 2.2%, and the area and mass flow rate of plume for IN_DCZ are reduced by 45.5 % (663.3 m²) and 50.3 % (6969.7 kg/s), respectively. When the inlet water ratio of the dry cooling zone exceeds 70 %, the plume control capability of IN_DCZ far exceeds that of EX_DCZ, reducing the plume area and mass flow rate by 98.2 % (1054.1 m²) and 98.7 % (9989.2 kg/s) compared to EX_DCZ. This study provides an application exploration for precise plume control in large wet cooling towers.

由于缺乏对羽流的定量评价方法，大型湿式冷却塔的羽流控制设计仍然面临着很大的挑战。本研究以冷却塔出口表面为参照，提出了羽流面积和羽流质量流量的计算方法。对比分析了内（IN_DCZ）和外（EX_DCZ）干冷区对混合式冷却塔性能的影响。在风力条件下，IN_DCZ的性能优于EX_DCZ。与EX_DCZ相比，IN_DCZ的出水温度降低了0.4℃，节水率提高了2.2%，羽流面积和质量流量分别减少45.5% （663.3 m2）和50.3% （6969.7 kg/s）。当干冷区进水比超过70%时，IN_DCZ的羽流控制能力远远超过EX_DCZ，羽流面积和质量流量比EX_DCZ分别减少98.2% （1054.1 m2）和98.7% （9989.2 kg/s）。本研究为大型湿式冷却塔羽流精确控制提供了应用探索。

{"title":"A comparative study on the effects of external and internal dry cooling zones on the performance of hybrid natural draft cooling towers","authors":"Weipeng Deng , Zhufeng Lin , Huinan Yang , Fengzhong Sun , Huaqiang Chu","doi":"10.1016/j.ijheatmasstransfer.2026.128354","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128354","url":null,"abstract":"<div><div>Due to the lack of quantitative evaluation methods for plumes, the design of plume control for large wet cooling towers still faces significant challenges. This study uses the outlet surface of cooling towers as the reference and proposes methods for calculating the plume area and the mass flow rate of the plume. Furthermore, a comparative analysis is conducted on the impact of internal (IN_DCZ) and external (EX_DCZ) dry cooling zones on the performance of hybrid cooling towers. Under wind conditions, the performance of IN_DCZ is better than that of EX_DCZ. Compared to EX_DCZ, the outlet water temperature of IN_DCZ reduces by 0.4 °C, the water-saving rate of IN_DCZ increases by 2.2%, and the area and mass flow rate of plume for IN_DCZ are reduced by 45.5 % (663.3 m<sup>2</sup>) and 50.3 % (6969.7 kg/s), respectively. When the inlet water ratio of the dry cooling zone exceeds 70 %, the plume control capability of IN_DCZ far exceeds that of EX_DCZ, reducing the plume area and mass flow rate by 98.2 % (1054.1 m<sup>2</sup>) and 98.7 % (9989.2 kg/s) compared to EX_DCZ. This study provides an application exploration for precise plume control in large wet cooling towers.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"259 ","pages":"Article 128354"},"PeriodicalIF":5.8,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940843","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Boiling dynamics on well-ordered porous layers: A lattice Boltzmann simulation study 有序多孔层上的沸腾动力学：晶格玻尔兹曼模拟研究

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-10 DOI: 10.1016/j.ijheatmasstransfer.2026.128367

Hengyu Hu, Haibo Huang

This study investigates pool boiling enhanced by the well-ordered porous layers using direct numerical simulations based on a coupled lattice Boltzmann method (LBM) and finite difference method (FDM). The simulations capture the dynamic behavior of the vapor–liquid interface during boiling. A physical model is developed to establish a scaling law relating the thickness of porous layers

H

to critical boiling times. Specifically, the inception time

t_{i}

, phase change time

t_{p}

, and gross boiling time

t_{g}

all exhibit a quadratic dependence on

H

. Furthermore, the study shows that under certain conditions, boiling bypasses the nucleate and transition regimes and proceeds directly to film boiling, resulting in the absence of a critical heat flux (CHF). This phenomenon is explained using Rayleigh–Taylor instability theory, from which a criterion is derived to predict the existence of CHF based on the relationship between the critical instability wavelength and the spacing between nucleation sites. The findings offer new insight into boiling mechanisms on porous layers and provide theoretical guidance for designing thermally efficient porous structures.

基于晶格玻尔兹曼法（LBM）和有限差分法（FDM）的直接数值模拟研究了有序多孔层对池沸腾的促进作用。模拟捕获了沸腾过程中汽液界面的动态行为。建立了一个物理模型，建立了多孔层厚度H与临界沸腾时间之间的标度规律。具体而言，起始时间ti、相变时间tp和总沸腾时间tg均与h呈二次依赖关系。此外，研究表明，在某些条件下，沸腾绕过核态和过渡态，直接进入膜态沸腾，导致没有临界热流密度（CHF）。用瑞利-泰勒不稳定性理论解释了这一现象，并根据临界不稳定性波长与成核位间距之间的关系，导出了预测CHF存在的判据。研究结果为研究多孔层的沸腾机理提供了新的思路，并为设计热效率高的多孔结构提供了理论指导。

{"title":"Boiling dynamics on well-ordered porous layers: A lattice Boltzmann simulation study","authors":"Hengyu Hu, Haibo Huang","doi":"10.1016/j.ijheatmasstransfer.2026.128367","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128367","url":null,"abstract":"<div><div>This study investigates pool boiling enhanced by the well-ordered porous layers using direct numerical simulations based on a coupled lattice Boltzmann method (LBM) and finite difference method (FDM). The simulations capture the dynamic behavior of the vapor–liquid interface during boiling. A physical model is developed to establish a scaling law relating the thickness of porous layers <span><math><mi>H</mi></math></span> to critical boiling times. Specifically, the inception time <span><math><msub><mrow><mi>t</mi></mrow><mrow><mi>i</mi></mrow></msub></math></span>, phase change time <span><math><msub><mrow><mi>t</mi></mrow><mrow><mi>p</mi></mrow></msub></math></span>, and gross boiling time <span><math><msub><mrow><mi>t</mi></mrow><mrow><mi>g</mi></mrow></msub></math></span> all exhibit a quadratic dependence on <span><math><mi>H</mi></math></span>. Furthermore, the study shows that under certain conditions, boiling bypasses the nucleate and transition regimes and proceeds directly to film boiling, resulting in the absence of a critical heat flux (CHF). This phenomenon is explained using Rayleigh–Taylor instability theory, from which a criterion is derived to predict the existence of CHF based on the relationship between the critical instability wavelength and the spacing between nucleation sites. The findings offer new insight into boiling mechanisms on porous layers and provide theoretical guidance for designing thermally efficient porous structures.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"259 ","pages":"Article 128367"},"PeriodicalIF":5.8,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145974941","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Modeling on thermal conductivity of petroleum hydrocarbons-contaminated soils considering preferential invasion pores and connection patterns 考虑优先侵入孔隙和连接模式的石油烃污染土壤导热系数建模

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-10 DOI: 10.1016/j.ijheatmasstransfer.2026.128348

Jun Bi , Huiqi Xia , Sheng Yang , Shengnian Wang , Tingting Wei , Wansheng Pei

Petroleum hydrocarbons (PHs) are compounds containing the elements carbon and hydrogen. The leaks of PHs during the PHs exploration, transportation, refining, and storage process usually contaminate the site, disrupt ecological environment and threaten human health. Therefore, the in-situ thermal desorption technology has been widely used to heat the contaminated sites and remove the pollutants, but the contaminants removal efficiency is controlled by thermal conductivity (TC) in the contaminated site. In this study, a theoretical model was developed by using different preferential invasion pores (i.e., parallel and series pores) and connection patterns between air and liquid mixture of water and PHs (i.e., parallel and series connections). The new model was expressed as a function of porosity, temperature, degree of saturation of PHs, and degree of saturation of water. The theoretical model was evaluated with TC values of diesel-contaminated soils, and good agreements between estimated and measured TC values were obtained. Moreover, all the estimated TC values determined by the new model strictly fall within the Wiener bounds, and most estimated TC results fall within the Hashin-Shtrikman bounds. The theoretical TC model will contribute to the understanding of heat transfer process in the PHs-contaminated site during the remediation process.

石油碳氢化合物（PHs）是含有碳和氢元素的化合物。小灵通在勘探、运输、提炼和贮存过程中发生泄漏，污染场地，破坏生态环境，威胁人体健康。因此，原位热解吸技术已被广泛用于对污染场地进行加热和去除污染物，但污染物的去除效率受污染场地的导热系数（TC）的控制。本研究利用不同优先侵入孔隙（即并联和串联）以及水与ph气液混合物的连接方式（即并联和串联）建立了理论模型。新模型表示为孔隙度、温度、ph饱和度和水饱和度的函数。用柴油污染土壤的TC值对理论模型进行了评价，得到了较好的TC值估计值和实测值。此外，新模型确定的所有估计TC值都严格落在Wiener界内，大多数估计TC结果落在Hashin-Shtrikman界内。理论TC模型将有助于理解修复过程中ph污染场地的传热过程。

{"title":"Modeling on thermal conductivity of petroleum hydrocarbons-contaminated soils considering preferential invasion pores and connection patterns","authors":"Jun Bi , Huiqi Xia , Sheng Yang , Shengnian Wang , Tingting Wei , Wansheng Pei","doi":"10.1016/j.ijheatmasstransfer.2026.128348","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128348","url":null,"abstract":"<div><div>Petroleum hydrocarbons (PHs) are compounds containing the elements carbon and hydrogen. The leaks of PHs during the PHs exploration, transportation, refining, and storage process usually contaminate the site, disrupt ecological environment and threaten human health. Therefore, the in-situ thermal desorption technology has been widely used to heat the contaminated sites and remove the pollutants, but the contaminants removal efficiency is controlled by thermal conductivity (TC) in the contaminated site. In this study, a theoretical model was developed by using different preferential invasion pores (i.e., parallel and series pores) and connection patterns between air and liquid mixture of water and PHs (i.e., parallel and series connections). The new model was expressed as a function of porosity, temperature, degree of saturation of PHs, and degree of saturation of water. The theoretical model was evaluated with TC values of diesel-contaminated soils, and good agreements between estimated and measured TC values were obtained. Moreover, all the estimated TC values determined by the new model strictly fall within the Wiener bounds, and most estimated TC results fall within the Hashin-Shtrikman bounds. The theoretical TC model will contribute to the understanding of heat transfer process in the PHs-contaminated site during the remediation process.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"259 ","pages":"Article 128348"},"PeriodicalIF":5.8,"publicationDate":"2026-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Physics-informed neural networks for 2D-transient inverse heat conduction problem involving static and moving heat source 涉及静态和移动热源的二维瞬态反热传导问题的物理神经网络

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-09 DOI: 10.1016/j.ijheatmasstransfer.2026.128349

M.S. Bidou, J.-G. Bauzin, N. Laraqi

In thermal engineering, the effectiveness of diagnosis, monitoring, and control depends on accurately identifying material properties and locating internal heat sources from limited temperature measurements. This work advances a physics-based hybrid learning framework for 2D thermal conduction, which combines data and physical priors to stabilize inference under limited measurement conditions. We address two complementary objectives: (i) thermophysical identification within an orthotropic medium, estimating the in-plane conductivity tensor

Λ = diag (λ_{x}, λ_{y})

and the volumetric heat capacity

ρ C

(with diffusivity reported a posteriori); and (ii) internal volumetric heat-source identification in an isotropic medium, recovering the Gaussian source’s flux amplitude, spatial position, and spatial dispersion, for both fixed and mobile centers. A PINN-based sensitivity analysis guides sensor placement to enhance identifiability with few measurements. Performance is evaluated on noise-free data and under additive Gaussian sensor noise (0.1 K and 0.5 K). Across both settings, the approach delivers high accuracy for material parameters and source localization, and low errors for source flux, supporting robust thermal inverse diagnostics with minimal instrumentation.

在热能工程中，诊断、监测和控制的有效性取决于准确识别材料特性和从有限的温度测量中定位内部热源。这项工作提出了一个基于物理的二维热传导混合学习框架，它结合了数据和物理先验，以稳定有限测量条件下的推断。我们解决了两个互补的目标：(i)在正交异性介质中进行热物理识别，估计平面内导热张量Λ=diag（Λ x， Λ y）和体积热容量ρC（后验报告扩散率）；（ii）在各向同性介质中进行内部体积热源识别，恢复固定和移动中心高斯源的通量振幅、空间位置和空间色散。基于pup的灵敏度分析指导传感器放置，以提高识别性与很少的测量。在无噪声数据和加性高斯传感器噪声（0.1 K和0.5 K）下评估性能。在这两种设置中，该方法提供了材料参数和源定位的高精度，并且源通量的误差很低，支持用最少的仪器进行强大的热逆诊断。

{"title":"Physics-informed neural networks for 2D-transient inverse heat conduction problem involving static and moving heat source","authors":"M.S. Bidou, J.-G. Bauzin, N. Laraqi","doi":"10.1016/j.ijheatmasstransfer.2026.128349","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128349","url":null,"abstract":"<div><div>In thermal engineering, the effectiveness of diagnosis, monitoring, and control depends on accurately identifying material properties and locating internal heat sources from limited temperature measurements. This work advances a physics-based hybrid learning framework for 2D thermal conduction, which combines data and physical priors to stabilize inference under limited measurement conditions. We address two complementary objectives: (i) thermophysical identification within an orthotropic medium, estimating the in-plane conductivity tensor <span><math><mrow><mi>Λ</mi><mo>=</mo><mi>diag</mi><mrow><mo>(</mo><msub><mrow><mi>λ</mi></mrow><mrow><mi>x</mi></mrow></msub><mo>,</mo><msub><mrow><mi>λ</mi></mrow><mrow><mi>y</mi></mrow></msub><mo>)</mo></mrow></mrow></math></span> and the volumetric heat capacity <span><math><mrow><mi>ρ</mi><mi>C</mi></mrow></math></span> (with diffusivity reported a posteriori); and (ii) internal volumetric heat-source identification in an isotropic medium, recovering the Gaussian source’s flux amplitude, spatial position, and spatial dispersion, for both fixed and mobile centers. A PINN-based sensitivity analysis guides sensor placement to enhance identifiability with few measurements. Performance is evaluated on noise-free data and under additive Gaussian sensor noise (0.1 K and 0.5 K). Across both settings, the approach delivers high accuracy for material parameters and source localization, and low errors for source flux, supporting robust thermal inverse diagnostics with minimal instrumentation.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"259 ","pages":"Article 128349"},"PeriodicalIF":5.8,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940773","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical investigation on flow instability of supercritical n-decane in a vertical upward tube with pyrolysis effects 超临界正癸烷在垂直向上管内流动不稳定性的数值研究

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-09 DOI: 10.1016/j.ijheatmasstransfer.2026.128342

Songbo Nan , Zeyuan Cheng , Xiang Li , Jingsong Huang , Jianqin Zhu

Flow instability of supercritical hydrocarbon fuels in regenerative cooling channels is a critical issue faced by scramjet engines. Existing research has largely overlooked the influence of pyrolysis on flow instability. This work numerically investigated the instability behaviors and mechanism of supercritical n-decane in a vertical tube, emphasizing the effects of inlet flow rate and pyrolysis. The instability boundaries under different pressures were also established. The results show that the pressure-drop curve exhibits a quintic behavior with two negative-slope regions, caused by sharp density variations in the pseudo-critical and pyrolysis temperature regions. At an inlet flow rate of 0.8 g/s, the fuel exhibits periodic density-wave oscillation at a frequency of 0.23 Hz. Density variation is the fundamental cause of instability, while buoyancy and pyrolysis act as key factors of the periodic oscillations. As the inlet mass flow rate increases from 0.41 g/s to 1.2 g/s, the instability evolves from flow drift coupled with density-wave oscillations to pure density-wave oscillations, and eventually to stable flow, with stability initially decreasing and then increasing. Pyrolysis transforms the pressure drop curve from a cubic to a quintic behavior, which in turn alters the mode of flow instability in the negative-slope regions of the pressure drop curve and shortens the oscillation period from 4.5 s to 4.3 s. The predicted flow instability boundaries under 2.5–4.0 MPa show a maximum deviation of 9.3 % from experimental data. These findings provide theoretical guidance for the safe and reliable design of regenerative cooling channels.

超临界碳氢燃料在再生冷却通道中的流动不稳定性是超燃冲压发动机面临的一个关键问题。现有研究在很大程度上忽略了热解对流动不稳定性的影响。本文对超临界正癸烷在垂直管内的不稳定行为和机理进行了数值研究，重点研究了入口流速和热解的影响。建立了不同压力下的不稳定边界。结果表明：由于准临界温度区和热解温度区密度的急剧变化，压降曲线呈现出具有两个负斜率区域的五次曲线特征；在进口流量为0.8 g/s时，燃料表现出频率为0.23 Hz的周期性密度波振荡。密度变化是不稳定的根本原因，而浮力和热解是周期性振荡的关键因素。当进口质量流量从0.41 g/s增加到1.2 g/s时，不稳定性从流动漂移耦合密度波振荡发展到纯密度波振荡，最终发展到稳定流动，稳定性先降低后增加。热解使压降曲线由三次行为转变为五次行为，从而改变了压降曲线负斜率区域的流动不稳定模式，振荡周期由4.5 s缩短至4.3 s。在2.5 ~ 4.0 MPa范围内，预测的流动不稳定边界与实验数据的最大偏差为9.3%。研究结果为安全可靠地设计蓄热式冷却通道提供了理论指导。

{"title":"Numerical investigation on flow instability of supercritical n-decane in a vertical upward tube with pyrolysis effects","authors":"Songbo Nan , Zeyuan Cheng , Xiang Li , Jingsong Huang , Jianqin Zhu","doi":"10.1016/j.ijheatmasstransfer.2026.128342","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128342","url":null,"abstract":"<div><div>Flow instability of supercritical hydrocarbon fuels in regenerative cooling channels is a critical issue faced by scramjet engines. Existing research has largely overlooked the influence of pyrolysis on flow instability. This work numerically investigated the instability behaviors and mechanism of supercritical n-decane in a vertical tube, emphasizing the effects of inlet flow rate and pyrolysis. The instability boundaries under different pressures were also established. The results show that the pressure-drop curve exhibits a quintic behavior with two negative-slope regions, caused by sharp density variations in the pseudo-critical and pyrolysis temperature regions. At an inlet flow rate of 0.8 <em>g</em>/s, the fuel exhibits periodic density-wave oscillation at a frequency of 0.23 Hz. Density variation is the fundamental cause of instability, while buoyancy and pyrolysis act as key factors of the periodic oscillations. As the inlet mass flow rate increases from 0.41 g/s to 1.2 g/s, the instability evolves from flow drift coupled with density-wave oscillations to pure density-wave oscillations, and eventually to stable flow, with stability initially decreasing and then increasing. Pyrolysis transforms the pressure drop curve from a cubic to a quintic behavior, which in turn alters the mode of flow instability in the negative-slope regions of the pressure drop curve and shortens the oscillation period from 4.5 s to 4.3 s. The predicted flow instability boundaries under 2.5–4.0 MPa show a maximum deviation of 9.3 % from experimental data. These findings provide theoretical guidance for the safe and reliable design of regenerative cooling channels.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"259 ","pages":"Article 128342"},"PeriodicalIF":5.8,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940842","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Binary collisions between slurry droplets at different ambient temperatures 浆液液滴在不同环境温度下的二元碰撞

IF 5.8 2区工程技术 Q1 ENGINEERING, MECHANICAL

International Journal of Heat and Mass Transfer

Pub Date : 2026-01-09 DOI: 10.1016/j.ijheatmasstransfer.2026.128327

Anastasia Islamova, Svetlana Kropotova, Andrey Klimenko, Stanislav Shulyaev

Understanding the specific aspects of binary interactions of coal-water slurry droplets is crucial for optimizing the transportation of this fuel and spraying in industrial applications. This research presents experimental findings for binary collisions of coal-water slurry droplets, when varying the ambient air temperature (from 25 to 200°C), concentration of solid coal particles (from 0.5 to 5%), and geometry of collisions. Using high-speed video recording, the following interaction regimes of droplets were recorded: bounce, coalescence, reflexive separation, and stretching separation. Droplet interaction regime maps were plotted to identify the boundaries between regimes depending on the solid phase concentration in the slurry and ambient temperature. The probability of occurrence of a regime was not significantly dependent on the coal concentration in the slurry in the considered range, but was very sensitive to the impact angle and velocity. It was hypothesized that the geometry of the lamella forming in off-center interaction determines the number of secondary fragments (child droplets) after its breakup. The inertial forces of droplets and thermophysical properties of the gas medium rather than the solid phase concentration in the liquid have a decisive effect on the droplet interaction outcome.

了解水煤浆液滴二元相互作用的具体方面对于优化这种燃料的运输和工业应用中的喷涂至关重要。本文研究了不同环境空气温度（25 ~ 200℃）、固体煤颗粒浓度（0.5 ~ 5%）和碰撞几何形状对水煤浆液滴二元碰撞的实验结果。采用高速录像技术，记录了液滴的弹跳、聚并、反射分离、拉伸分离等相互作用过程。根据浆液中固相浓度和环境温度，绘制了液滴相互作用状态图，以确定状态之间的边界。在考虑的范围内，一种状态发生的概率与浆体中煤的浓度无关，但对冲击角和冲击速度非常敏感。据推测，在离中心相互作用中形成的薄片的几何形状决定了其破裂后的次级碎片（子液滴）的数量。液滴的惯性力和气体介质的热物理性质，而不是液体中固相浓度，对液滴相互作用的结果有决定性的影响。

{"title":"Binary collisions between slurry droplets at different ambient temperatures","authors":"Anastasia Islamova, Svetlana Kropotova, Andrey Klimenko, Stanislav Shulyaev","doi":"10.1016/j.ijheatmasstransfer.2026.128327","DOIUrl":"10.1016/j.ijheatmasstransfer.2026.128327","url":null,"abstract":"<div><div>Understanding the specific aspects of binary interactions of coal-water slurry droplets is crucial for optimizing the transportation of this fuel and spraying in industrial applications. This research presents experimental findings for binary collisions of coal-water slurry droplets, when varying the ambient air temperature (from 25 to 200°C), concentration of solid coal particles (from 0.5 to 5%), and geometry of collisions. Using high-speed video recording, the following interaction regimes of droplets were recorded: bounce, coalescence, reflexive separation, and stretching separation. Droplet interaction regime maps were plotted to identify the boundaries between regimes depending on the solid phase concentration in the slurry and ambient temperature. The probability of occurrence of a regime was not significantly dependent on the coal concentration in the slurry in the considered range, but was very sensitive to the impact angle and velocity. It was hypothesized that the geometry of the lamella forming in off-center interaction determines the number of secondary fragments (child droplets) after its breakup. The inertial forces of droplets and thermophysical properties of the gas medium rather than the solid phase concentration in the liquid have a decisive effect on the droplet interaction outcome.</div></div>","PeriodicalId":336,"journal":{"name":"International Journal of Heat and Mass Transfer","volume":"259 ","pages":"Article 128327"},"PeriodicalIF":5.8,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940848","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0