International Journal of Thermal Sciences最新文献

{"title":"Microwave hybrid joining using SAC305-xNi@Sn solder paste to achieve superior performance and high-efficiency heating and unveiling cross-scale mechanisms","authors":"Shuai Zhang ,&nbsp;Chen Zeng ,&nbsp;Shuangcheng Ma ,&nbsp;Peng He ,&nbsp;Tianran Ding ,&nbsp;Weimin Long ,&nbsp;Sujuan Zhong ,&nbsp;Shuye Zhang","doi":"10.1016/j.ijthermalsci.2025.109947","DOIUrl":"10.1016/j.ijthermalsci.2025.109947","url":null,"abstract":"<div><div>Microwave hybrid joining (MHJ) is an innovative, high-efficiency technique that uniformly heats materials, offering superior performance compared to traditional methods. This study developed a multi-physical MHJ model using silicon carbide (SiC) as the susceptor. SAC305-xNi@Sn solder paste was found to enable compound heating, significantly improving joining efficiency. The temperature field, electric field, and maximum electromagnetic power loss density distributions of the self-designed dual susceptors were analyzed. Ni/Sn-Ag-Cu-xNi@Sn/Ni joints were fabricated and compared with reflow soldering. The fracture mechanism and the optimal Ni@Sn content were analyzed. The multi-physics simulation examined the cross-scale mechanisms of MHJ. The results indicate that incorporating 3.6 g of SnCl₂·2H₂O uniformly covers Ni@Sn nanoparticles, meeting weldability standards. MHJ technology achieves a shear strength of 40.20 MPa at 2.45 GHz, 2 kW, a peak temperature of 400 °C, and a 5-min exposure time, which is 35.67 % higher than that of reflow soldering (29.63 MPa). Under identical process parameters, MHJ infused with 1 % Ni@Sn nanoparticles achieves a shear strength of 43.11 MPa, representing a 45.49 % increase over the shear strength of reflow soldering (29.63 MPa). SAC305 has a thickness of 3.1 mm, a minimum reflectance of −53.06 dB at 9.28 GHz, and an effective absorption bandwidth of 2.39 GHz. Ni@Sn exhibits a minimum reflectance of −2.71 dB and an optimal thickness of 3.04 mm at 4.32 GHz.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"215 ","pages":"Article 109947"},"PeriodicalIF":4.9,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143891555","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}

{"title":"Molecular dynamics study on the effects of cuboid nanostructure on the distribution of local thermal resistance at a solid–liquid interface","authors":"Takuto Omori,&nbsp;Masahiko Shibahara","doi":"10.1016/j.ijthermalsci.2025.109949","DOIUrl":"10.1016/j.ijthermalsci.2025.109949","url":null,"abstract":"<div><div>This study focuses on thermal transport at the interface between solid and liquid with various cuboid nanostructure systems. We calculated the solid–liquid interfacial thermal resistance (ITR) and the distribution of local ITRs with a 0.2 nm spatial resolution. The results were obtained using non–equilibrium molecular dynamics. Applying a thermal circuit model, we computed the thermal resistance by combining the local ITRs. Also, we introduced spectral analysis to explain the distribution of local ITR magnitudes. As a result, we found that the local ITRs decreased at the top corner of the nanostructure and increased at its base. The thermal transport at the top corner contributed significantly to the total thermal transport at the solid–liquid interface. It was revealed that the ratio of the overall ITR to the combined local ITRs agreed with the ratio of the area of a flat surface to the area along the lower wall and the nanostructure, including the Cassie–Baxter state, only when the local temperature jumps around the interface are closely similar i.e. the interaction strength between solid and liquid is not extremely high. Moreover, from spectral analysis of solid atoms, we found that the vibrational density of states (VDOS) and the spectral heat flux of the solid atoms at the top corner of the nanostructure peaked in a low–frequency range and the VDOS overlap became higher at the top corner in all cases. This strong vibrational coupling is another factor contributing to the lowest local ITR at the top corner of the nanostructure.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"215 ","pages":"Article 109949"},"PeriodicalIF":4.9,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143891554","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}

{"title":"Investigation of hydrothermal performance and irreversibility production rate of ferrosoferric oxide/water nanofluid in corrugated-converging pipes with varying geometry parameters","authors":"Olatomide Gbenga Fadodun ,&nbsp;Odunayo Olawuyi Fadodun ,&nbsp;Amro H. Al-Tohamy ,&nbsp;Amr Kaood","doi":"10.1016/j.ijthermalsci.2025.109964","DOIUrl":"10.1016/j.ijthermalsci.2025.109964","url":null,"abstract":"&lt;div&gt;&lt;div&gt;In this study, hydrothermal performance and irreversibility production rate in ferrosoferric oxide (Fe&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)/water nanofluid flowing in corrugated-converging pipes (CCPs) in turbulent flow regime have been examined. The ferrosoferric oxide (Fe&lt;sub&gt;3&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt;)/water nanofluid is modeled using discrete phase and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;k&lt;/mi&gt;&lt;mo&gt;−&lt;/mo&gt;&lt;mi&gt;ω&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; turbulent models in Ansys Fluent. The impact of various factors on the Poiseuille number &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, average Nusselt number &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, performance evaluation criterion &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mi&gt;P&lt;/mi&gt;&lt;mi&gt;E&lt;/mi&gt;&lt;mi&gt;C&lt;/mi&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, and irreversibility production rate are thoroughly examined. These factors include corrugation profiles (rectangular, trapezoidal, and spherical), Reynolds number &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;(&lt;/mo&gt;&lt;mrow&gt;&lt;mn&gt;5.0&lt;/mn&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mn&gt;3&lt;/mn&gt;&lt;/msup&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;mn&gt;3.0&lt;/mn&gt;&lt;mo&gt;×&lt;/mo&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, normalized amplitude of corrugation (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mrow&gt;&lt;mn&gt;0.025&lt;/mn&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;mfrac&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/mfrac&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;mn&gt;0.035&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, normalized width of corrugation (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mrow&gt;&lt;mn&gt;0.2&lt;/mn&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;mfrac&gt;&lt;mi&gt;w&lt;/mi&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/mfrac&gt;&lt;mo&gt;≤&lt;/mo&gt;&lt;mn&gt;0.4&lt;/mn&gt;&lt;/mrow&gt;&lt;mo&gt;)&lt;/mo&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, convergence diameter ratio (1.0 ≤ &lt;em&gt;DR&lt;/em&gt; ≤ 2.0), and nanoparticles concentration (0.0 % ≤ &lt;em&gt;VR&lt;/em&gt; ≤ 2.0 %). The findings revealed that the &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; in CCPs is higher than that of smooth pipes, albeit at the expense of increased &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. For instance, at &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;msup&gt;&lt;mn&gt;10&lt;/mn&gt;&lt;mn&gt;4&lt;/mn&gt;&lt;/msup&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;V&lt;/mi&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;mo&gt;%&lt;/mo&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;2.0&lt;/mn&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mfrac&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/mfrac&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0.025&lt;/mn&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mi&gt;a&lt;/mi&gt;&lt;mi&gt;n&lt;/mi&gt;&lt;mi&gt;d&lt;/mi&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mfrac&gt;&lt;mi&gt;w&lt;/mi&gt;&lt;mi&gt;D&lt;/mi&gt;&lt;/mfrac&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;0.4&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, the values of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; and &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;f&lt;/mi&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; for rectangular, trapezoidal, and spherical CCPs and smooth straight pipe, which serves as the reference pipe (RP), are {156.96, 153.34, 137.00, and 103.35} and {13938.44, 11335.35, 7537.07, and 551.71}, respectively. In addition, it was found that, when compared to RP, the average volumetric entropy production rate due to the temperature gradient &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mo&gt;⟨&lt;/mo&gt;&lt;msubsup&gt;&lt;mi&gt;S&lt;/mi&gt;&lt;mrow&gt;&lt;mi&gt;t&lt;/mi&gt;&lt;mi&gt;h&lt;/mi&gt;&lt;/mr","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"215 ","pages":"Article 109964"},"PeriodicalIF":4.9,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143886605","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}

{"title":"Numerical investigations of flow and heat transfer characteristics of a regenerative cooling channel using supercritical CO2 with different cross-section shapes","authors":"Xinrui Zhang ,&nbsp;Wenjie Guo ,&nbsp;Guangjun Gao ,&nbsp;Wenxiong Xi ,&nbsp;Jian Liu ,&nbsp;Bengt Sunden","doi":"10.1016/j.ijthermalsci.2025.109965","DOIUrl":"10.1016/j.ijthermalsci.2025.109965","url":null,"abstract":"<div><div>Because of the excellent heat and mass transfer ability, this study employed supercritical CO₂ as a supplementary coolant to kerosene for regenerative cooling at extremely high Mach numbers (Ma≥8). The study investigated the effects of cross-section shapes, flow patterns, and wall materials on the flow structures and heat transfer performance associated with entropy generation analysis. From the results, the triangular channel has highest heat transfer coefficient, while the square channel has the lowest the friction factor. Considering both he first and second law of thermodynamics, it is concluded that the channel with the triangular cross-section provides the best thermal performance. The channel with the circular cross-section shows better performance at the channel outlet, primarily attributed to its larger turbulent kinetic energy and thinner momentum and thermal boundary layers. The opposite flow pattern of adjacent channels can not only reduce the maximum wall temperature by at least 10 %, but also improve the wall temperature uniformity and promote heat transfer between adjacent channels. Compared with high-temperature alloys, using Cu as channel materials can greatly increase the heat transfer performance by 16.7 %.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"215 ","pages":"Article 109965"},"PeriodicalIF":4.9,"publicationDate":"2025-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887809","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}

{"title":"Conduction-convection coupled heat and moisture transfer in the open-width pre-drying for elastic fabrics","authors":"Huimin Chen ,&nbsp;Weilong Shu ,&nbsp;Gaoyu Li ,&nbsp;Shuting Lian ,&nbsp;Zhiping Mao ,&nbsp;Di Zhou","doi":"10.1016/j.ijthermalsci.2025.109963","DOIUrl":"10.1016/j.ijthermalsci.2025.109963","url":null,"abstract":"<div><div>A novel open-width pre-drying scheme is presented in this study, which utilizes a large drum and hot air as dual heat sources for elastic fabrics. The aim is to prevent the migration of absorbed dye liquor at elevated temperatures and ensure that the elastic fabric attains optimal moisture content. This approach effectively addresses significant challenges in open-width drying, such as fabric deformation, curled edges, and the absence of specialized equipment. These issues have historically hindered the development and application of efficient drying technologies for elastic fabrics. To support this approach, a heat and mass transfer model is established to simulate the pre-drying process, incorporating moisture transfer within the fabric and the transitions between various moisture states. The model also defines boundary conditions based on the fabric's position within the pre-drying setup. The accuracy of the proposed model is validated against experimental data under various conditions, revealing maximum relative deviations of 34.7 % in moisture content and 2.2 % in temperature, along with high correlation coefficients of 0.99 and 0.96. This confirms effectiveness of the model in capturing moisture transfer and heat exchange dynamics during the pre-drying process. The drying process follows a three-stage pattern influenced by parameters such as drum temperature and fabric feed speed. It is recommended to maintain lower drum temperatures while ensuring higher jet temperature, and to optimize drying time by adjusting fabric feed speed. These insights are essential to enhancing drying efficiency and quality in the open-width pre-drying for elastic fabrics.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"215 ","pages":"Article 109963"},"PeriodicalIF":4.9,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143887808","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}

{"title":"Numerical simulation of thermal transfer in polyimide nanofiber aerogels by 3D dual diameter Voronoi models","authors":"Yiqing Shao ,&nbsp;Yongzhen Pei ,&nbsp;Zhenrong Zheng","doi":"10.1016/j.ijthermalsci.2025.109941","DOIUrl":"10.1016/j.ijthermalsci.2025.109941","url":null,"abstract":"<div><div>The investigation of heat transfer in nanofiber aerogels (NFAs) is crucial for predicting and designing aerogels that achieve desirable thermal performances for various industrial applications. However, limited research has been conducted on numerical modeling of NFAs due to the challenges associated with reconstructing their structure. In this work, we present a 3D dual diameter Voronoi model to evaluate the thermal conductivity of NFAs. As an example, polyimide NFAs are considered. The predicted thermal conductivity values show good agreement with various experimental data with all relative errors being less than 5%. Furthermore, several influential parametric factors including the nanofiber diameter, the ratio between different diameters nanofibers and the structure of nanofibers are investigated. The results indicated that the thermal conductivity of NFAs increase with both the nanofiber diameter and the ratio of coarse nanofibers. Additionally, the intersection between coarse and fine nanofibers which along with the heat transfer direction and the location will influences the thermal conductivity of NFAs. This certainly demonstrates the potential of the dual diameter Voronoi model for use in the predicting and designing of the NFAs in the various fields such as thermal insulation or the energy management.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"215 ","pages":"Article 109941"},"PeriodicalIF":4.9,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143882598","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}

{"title":"Investigation on the unsteady characteristics of flow and heat transfer in different channels of turbine blade leading edge","authors":"Jinfu Chen ,&nbsp;Ran Yao ,&nbsp;Liwei Ma ,&nbsp;Jianhua Wang ,&nbsp;Xiaohong Wang ,&nbsp;Ming Gan","doi":"10.1016/j.ijthermalsci.2025.109962","DOIUrl":"10.1016/j.ijthermalsci.2025.109962","url":null,"abstract":"<div><div>In this work, the large eddy simulation (LES) method is used to study the instantaneous and time-averaged characteristics of flow and heat transfer in three internal structures i.e., swirl cooling (SC), impingement cooling (IC), double chamber cooling (DC) in the leading edge of a turbine blade at three Reynolds numbers (6.0 × 10³, 9.0 × 10³, 1.2 × 10⁴). Comparison with RANS method, LES method can provide internal cooling designers with a more comprehensive understanding of flow and heat transfer. The numerical results reveal the following important conclusions: (1) At the view point of time-averaged, the tangential jet in SC and DC can significantly increase the heat transfer rate (<em>Nu</em>), and therefore their heat transfer rates (<em>Nu</em>) are higher than that of IC, but IC has the lowest friction resistance. (2) At the view point of unsteady analysis, the flow instability of SC along the flow direction increases with <em>Re</em>, while the flow instability of DC decreases. The heat transfer rate (<em>Nu</em>) instability of IC is the highest, at Re = 6.0 × 10³, the <em>Nu</em> fluctuation amplitude of IC is increased by 34.9 % compared with SC.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"215 ","pages":"Article 109962"},"PeriodicalIF":4.9,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143882597","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}

{"title":"Numerical simulation of microwave ablation of lung tumor near the bronchus","authors":"Ning Wu ,&nbsp;Huihui Liu ,&nbsp;Xiaohua Song ,&nbsp;Qun Nan","doi":"10.1016/j.ijthermalsci.2025.109958","DOIUrl":"10.1016/j.ijthermalsci.2025.109958","url":null,"abstract":"<div><div>This paper aims to investigate the key factors affecting the efficacy of microwave ablation (MWA) of lung tumors near the bronchus. A lung anatomical model with three-level bronchial branches was established and a finite element analysis was developed to determine the temperature distribution. The ablation effect under different antenna-bronchial outer wall spacing, air velocity, and tumor diameter was compared and evaluated. The results show that there is a heat sink effect significantly related to the distance of antenna-bronchial outer wall. When the distance increases from 5.0 mm to 12.5 mm, the ablation volume of lung tissue increases by 0.96 cm³, while the air velocity increases from 0.5 m/s to 1.0 m/s, the maximum ablation volume decreases by 0.11 cm³. Tumor size also has a significant effect on MWA. When a 1 cm-diameter tumor is close to the bronchial outer wall, even if we choose the ablation scheme with less energy, which is [40 W, 2 min], the ablation process still penetrates the bronchus. The increase in tumor size leads to the increase of incomplete ablation rate. For 2 cm-diameter tumor, it is necessary to choose the ablation combination with higher energy [50 W, 8 min] or [60 W, 5 min] to avoid inadequate ablation.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"215 ","pages":"Article 109958"},"PeriodicalIF":4.9,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143878626","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}

{"title":"A modified lumped parameter droplet flash evaporation model based on one-dimensional flash evaporation model","authors":"Zhongyuan Huang ,&nbsp;Haojie Xie ,&nbsp;Zhenzhong Li ,&nbsp;Shanshan Bu ,&nbsp;Deqi Chen","doi":"10.1016/j.ijthermalsci.2025.109950","DOIUrl":"10.1016/j.ijthermalsci.2025.109950","url":null,"abstract":"<div><div>Spray flash evaporation technology is widely applied in various industrial and medical fields, including energy utilization, chemical engineering, nuclear power plants, and pharmaceutical engineering. Achieving accurate numerical simulation of the spray flash evaporation process is critical. According to the linear relationship between the evaporation residue and time on the semi-logarithmic scale during droplet flash evaporation, this study modifies the conventional droplet lumped parameter flash evaporation model based on one-dimensional flash evaporation model to improve the prediction accuracy of the transient characteristics of the droplet temperature. The results demonstrate that the modified model provides better agreement with both the one-dimensional flash evaporation model and experimental data compared to the unmodified lumped parameter model. The modified model can accurately predict the temperature variation of droplets. Subsequently, this study focuses on a vertical flash vessel, where the modified lumped parameter flash evaporation model is implemented into commercial software ANSYS Fluent within the Eulerian-Lagrangian framework using User Defined Functions (UDF). The numerical simulation results of the original model and the modified flash evaporation model are compared with experimental data, verifying the accuracy of the modified spray flash evaporation numerical simulation. Furthermore, through three-dimensional numerical simulation of the spray flash evaporation process, the transient characteristics of vapor and droplets are analyzed. This study proposes a modified lumped parameter droplet flash evaporation model and a spray flash numerical simulation method, which provide effective tools for a deeper understanding of the spray flash process and its industrial applications.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"215 ","pages":"Article 109950"},"PeriodicalIF":4.9,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143876630","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}

{"title":"Energy and flow conjuncture in knee joint synovial fluid: A Brinkman-based numerical study","authors":"Shahid Hasnain ,&nbsp;Nawal Odah Al-Atawi ,&nbsp;Muhammad Saqib","doi":"10.1016/j.ijthermalsci.2025.109934","DOIUrl":"10.1016/j.ijthermalsci.2025.109934","url":null,"abstract":"<div><div>In this article, we explore the modeling of the synovial membrane, which plays an essential role in regulating the flow of synovial fluid, ensuring proper lubrication, facilitating nutrient transport, and removing waste within the knee joint. The flow of synovial fluid, a non-Newtonian fluid containing large hyaluronan molecules, is intricately influenced by the properties of the synovial membrane, which acts as a porous medium. To explore this dynamic, the Brinkman equation, an extension of Darcy’s law, is utilized for the first time to study the synovial membrane, introducing a novel approach to the analysis. This equation is particularly relevant as it accounts for both viscous forces and the permeability of the membrane, allowing for a more accurate representation of fluid behavior in regions where synovial fluid interacts with the porous membrane. Additionally, the energy equation is critical in understanding how heat transfer influences synovial fluid dynamics. Within biological joints, temperature variations can occur due to metabolic processes, friction from movement, or external factors such as injury or inflammation. These temperature differences have a direct impact on the fluid’s viscosity and the membrane’s permeability, both of which are central to regulating fluid movement. When we consider the flow in the x-direction, it is largely governed by factors such as permeability, heat transfer properties, and viscous resistance within the fluid. In contrast, flow in the y-direction introduces an additional component, buoyancy forces driven by temperature gradients. These forces, characterized by the Grashof number, interact with the flow and modify its behavior in the vertical direction, where natural convection due to temperature differences may complement or oppose the flow driven by external forces. The Peclet number, derived from the energy equation, further highlights the balance between convective and diffusive heat transfer. This interplay is crucial in understanding how heat generated during joint movement, or from external sources, affects both the temperature profile and the fluid flow within the joint. By incorporating these non-dimensional numbers, the Grashof number, Darcy number, Peclet number, and Reynolds number into the modeling framework, we gain a deeper understanding of the complex mechanisms that govern synovial fluid movement and heat distribution within the knee joint. These numbers provide valuable insight into how external factors such as temperature, fluid viscosity, and joint movement interact, allowing for a more comprehensive study of both normal physiological conditions and pathological scenarios, such as inflammation or joint degeneration.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"215 ","pages":"Article 109934"},"PeriodicalIF":4.9,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143874128","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}