International Journal of Thermal Sciences最新文献

{"title":"Investigating the effects of design parameters on heat transfer rate and fouling factor in full-scale gas-to-gas coolers: A numerical study","authors":"Sandeep Aryal ,&nbsp;Shinku Lee ,&nbsp;Kwangkook Jeong","doi":"10.1016/j.ijthermalsci.2025.109721","DOIUrl":"10.1016/j.ijthermalsci.2025.109721","url":null,"abstract":"<div><div>This paper conducts a comprehensive numerical analysis to investigate the influence of design parameters on heat transfer rates and fouling factors in a steady-state Gas-to-Gas Cooler (GGC) using a multi-phase heat and mass transfer model. The study focuses on fouling mechanisms particularly related to inertial impaction and thermophoretic deposition. Employing a MATLAB-based single-tube finite difference method, the research explores the impact of varying transverse pitch (<span><math><mrow><mi>S</mi><mi>T</mi></mrow></math></span>), longitudinal pitch (<span><math><mrow><mi>S</mi><mi>L</mi></mrow></math></span>), fin height (<span><math><mrow><mi>F</mi><mi>h</mi></mrow></math></span>), and fin density (<span><math><mrow><mi>F</mi><mi>d</mi></mrow></math></span>) on heat transfer rates and fouling factors. The MATLAB program dynamically adjusts the number of tubes in the duct while maintaining constant GGC duct dimensions. The results indicate that reducing transverse pitch (<span><math><mrow><mi>S</mi><mi>T</mi></mrow></math></span>) enhances heat transfer rates from increasing flue gas velocity and heat transfer coefficients, concurrently reducing fouling through decreased impaction rates. Conversely, decreasing longitudinal pitch <span><math><mrow><mo>(</mo><mi>S</mi><mi>L</mi></mrow></math></span>), fin height (<span><math><mrow><mi>F</mi><mi>h</mi></mrow></math></span>), and fin density (<span><math><mrow><mi>F</mi><mi>d</mi></mrow></math></span>) lead to increased heat transfer rates and fouling. Model validation against measured power plant data demonstrates an average discrepancy of 1 % for outlet flue gas and water temperatures, offering valuable insights for economically selecting GGC dimensions based on specific heat transfer requirements. The information presented from this analysis can assist designers and engineers in optimizing GGC performance.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"211 ","pages":"Article 109721"},"PeriodicalIF":4.9,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138075","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":"Forced convective heat transfer over twisted and perforated forked pin fin heat sink: A numerical study","authors":"Md Ishtiaque Hossain,&nbsp;Md Samiul Haider Chowdhury,&nbsp;Syed Shaheer Uddin Ahmed,&nbsp;Abu Hamja,&nbsp;Istiaq Jamil Siddique","doi":"10.1016/j.ijthermalsci.2025.109719","DOIUrl":"10.1016/j.ijthermalsci.2025.109719","url":null,"abstract":"<div><div>The pin fin structure's design and shape play a critical role in stringent heat transfer management, especially for the robust advancement of electrical devices. This numerical study illustrates the impact of forced convective heat transfer and fluid flow behaviors on a staggered rectangular fork-shaped pin fin (RFPF) heat sink. Effects of one-slot and two-slots, the twisting of the lids of the two-slotted RFPF from 5° to 90°, and circular perforations are studied for different flow velocities. The study is carried out using the Navier-Stokes equation and RANS-based <span><math><mrow><mi>k</mi><mo>−</mo><mi>ε</mi></mrow></math></span> turbulence model and validated against both experimental and numerical literature data. At the highest Reynolds number, results indicated a 158 % and 141 % increase in hydrothermal performance factor compared to cylindrical pin fin for 0° and 55° twisted double-slotted RFPF. At this twisting angle (55°), the highest Nusselt number was obtained for all cases. Implementation of circular perforation further enhanced heat transfer by decreasing the pressure drop as well as lowering thermal resistance.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"211 ","pages":"Article 109719"},"PeriodicalIF":4.9,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138701","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":"Multi-position melting uniformity based on hot-air welding technology: Numerical simulation and experimental studies","authors":"Yang Hong ,&nbsp;Mingxing Zhang ,&nbsp;Wei Zhang ,&nbsp;Shujing Sha ,&nbsp;Zailong Jiang ,&nbsp;Xiaodong Wang","doi":"10.1016/j.ijthermalsci.2025.109722","DOIUrl":"10.1016/j.ijthermalsci.2025.109722","url":null,"abstract":"<div><div>Multi-position hot air welding technology is a high-performance welding process that involves simultaneous heating and melting across multiple positions to achieve welding formation. Taking the Audi airbag logo as an example in this study, the weldments at different positions exhibit inconsistent heating states. Constructing an appropriate heat transfer geometric model is crucial for improving the uniformity of heat received by the weldments. Consequently, CFD (Computational Fluid Dynamic) simulation technology employs to investigate the impact of various geometric models on the surface heat transfer coefficient, temperature, air velocity, and internal temperature distribution within the weldments. The research results indicate that employing circular outlets for the branch tubes of the heating chamber is more conducive to ensuring uniform heating of the weldments compared to square and triangular outlets. The increase in the length of the main chamber of the heating chamber favors uniform heating of the weldments among various work positions but hinders heat conduction. Moreover, extending the length of the branch tubes within the heating chamber is detrimental to both uniform heating of the weldments at different work positions and heat conduction. The final determination sets the length of the main chamber at 100 mm and the branch tubes at 50 mm. This model controls the difference in surface heat transfer coefficients among the weldments at various work positions to approximately 12 %, with an air velocity variation of around 5 %. The weldments obtained from the experiments exhibited consistent external shapes, with a tensile strength variation of 6.54 %, which meets the practical requirements of engineering applications.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"211 ","pages":"Article 109722"},"PeriodicalIF":4.9,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138076","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 investigation of hydrogen addition effects on combustion chamber wall heat flux","authors":"Fatemeh Fayyazi,&nbsp;Amir Mahdi Tahsini,&nbsp;Seyed Erfan Vahabi","doi":"10.1016/j.ijthermalsci.2025.109715","DOIUrl":"10.1016/j.ijthermalsci.2025.109715","url":null,"abstract":"<div><div>The present work is a numerical investigation of hydrogen addition into the methane fuel of an industrial combustion chamber which operates at high pressure and also a research burner that operates at atmospheric pressure. The focus is on the impacts of hydrogen addition on the wall heat flux of the combustion chamber. The studies are performed while the average exit temperature of the combustion chambers is kept almost constant according to the operational considerations and criteria. It is expected that with hydrogen addition, the length of flames will decrease, but the effect of resulting flow changes on the heat transfer rate of the burner's wall is under consideration here. The results demonstrate that the wall heat flux may significantly change despite keeping the exit average temperature constant, in such a way that it may increase in one combustion chamber, and decrease in another.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"211 ","pages":"Article 109715"},"PeriodicalIF":4.9,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138696","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":"Experimental investigation of a wall-bounded dual jet flow for varying Reynolds number: Flow visualisation, hydrodynamic characteristics, and associated heat transfer","authors":"P.J. Murphy ,&nbsp;S. Alimohammadi ,&nbsp;S.M. O'Shaughnessy","doi":"10.1016/j.ijthermalsci.2025.109699","DOIUrl":"10.1016/j.ijthermalsci.2025.109699","url":null,"abstract":"&lt;div&gt;&lt;div&gt;A wall bounded dual jet is the combination of a wall jet, flowing adjacent to a solid boundary, and a second parallel flowing jet offset from the boundary by some distance. The dual jet flow is distinctly different to that of either wall or offset jet, particularly in the region near the jet exit plane. This study represents just the 2&lt;sup&gt;nd&lt;/sup&gt; experimental investigation of the flow characteristics of a dual jet flow past a solid surface. The primary aim of the present investigation is to capture flow data to accompany the dual jet thermal data previously published by the authors and to provide further context to the reported findings. A bespoke experimental apparatus is constructed to observe the flow behavior using particle image velocimetry (PIV). The experimental setup is first validated by comparison of results for a single wall jet and a single offset jet with those available in literature. Then, a dual jet flow field is investigated for a Reynolds number range from &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;5&lt;/mn&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mn&gt;500&lt;/mn&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;12&lt;/mn&gt;&lt;mo&gt;,&lt;/mo&gt;&lt;mn&gt;000&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; for a jet width of &lt;span&gt;&lt;math&gt;&lt;mi&gt;w&lt;/mi&gt;&lt;mo&gt;=&lt;/mo&gt;&lt;mn&gt;7&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;mi&gt;m&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;, where both the offset ratio and a velocity ratio are maintained at a constant value of &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mn&gt;1&lt;/mn&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. Time-averaged PIV analysis reveals that the jets immediately deflect toward one another, with a slow-moving recirculation zone between them presenting as a pair of counter rotating vortices. The data suggests that the merge point moves marginally upstream with increasing &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;, while moving further from the solid wall, whereas the streamwise positions of the vortex centres appear relatively unaffected by &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;. Increasing &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;R&lt;/mi&gt;&lt;mi&gt;e&lt;/mi&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; leads to a slight reduction in the size of the recirculation zone, where the defection of both jets is noticeably increased. The findings of the present study suggest that the shape of the characteristic local Nusselt number (&lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;msub&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt;) profiles previously reported in the literature can readily be attributed to the unique features observed inside the dual jet flow field. In particular, the observed deflection of the wall jet away from the solid wall is found to be the direct cause of the local &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;msub&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; minimum, and the subsequent re-impingement of the jet flow on the wall boundary induces the succeeding local &lt;span&gt;&lt;math&gt;&lt;mrow&gt;&lt;mi&gt;N&lt;/mi&gt;&lt;msub&gt;&lt;mi&gt;u&lt;/mi&gt;&lt;mi&gt;x&lt;/mi&gt;&lt;/msub&gt;&lt;/mrow&gt;&lt;/math&gt;&lt;/span&gt; maximum, where the occurrence of a wall jet deflection and re-impingement has not yet been reported on by any prior dual jet studies in the published literature.","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"211 ","pages":"Article 109699"},"PeriodicalIF":4.9,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of the combined Rayleigh-Taylor/Kelvin-Helmholtz instability on turbulent thermal stratification","authors":"Binbin Pei ,&nbsp;Yayao Zhang ,&nbsp;Weiwei Hu ,&nbsp;Jie Zhang ,&nbsp;Ning Huang","doi":"10.1016/j.ijthermalsci.2025.109708","DOIUrl":"10.1016/j.ijthermalsci.2025.109708","url":null,"abstract":"<div><div>We numerically investigate the effect of the combined Rayleigh-Taylor (RT) Kelvin-Helmholtz (KH) instability on turbulent thermal stratification by solving the low-Mach-number approximation of the Navier-Stokes equations. The RT instability induced by unstable thermal stratification is considered with Atwood numbers of 0.3. The strength of KH instability (or shear) is changed using the velocity difference between two streams. Compared with the mixing flow dominated by RT instability, we find that the turbulence and the thermal mixing are drastically inhibited by the addition of intermediate shear. Correspondingly, the turbulent kinetic energy, mixing efficiency and Nusselt number are decreased. Further, with increasing the velocity difference between two streams, we find that the thermal mixing efficiency and Nusselt number increase when the shear dominates the recovery of turbulence, which can be attributed to the larger contribution of gradient production than that of buoyancy production. This work provides theoretical support to control and modulate the thermal mixing in engineering applications through changing velocity of jet flow.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"211 ","pages":"Article 109708"},"PeriodicalIF":4.9,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138698","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":"Performance enhancement of near-field thermophotovoltaic systems by coupling black phosphorus and natural hyperbolic material","authors":"Ruiyi Liu ,&nbsp;Haotuo Liu ,&nbsp;Yang Hu ,&nbsp;Zheng Cui ,&nbsp;Xiaohu Wu","doi":"10.1016/j.ijthermalsci.2025.109712","DOIUrl":"10.1016/j.ijthermalsci.2025.109712","url":null,"abstract":"<div><div>The contribution of evanescent waves enables efficient thermoelectric conversion in near-field thermophotovoltaic (NFTPV), thereby offering a promising avenue for waste heat recovery. Previous researches indicate that hyperbolic materials (HMs) have promising prospects as emitters in NFTPV systems, while their potential to combine with two-dimensional materials remains to be explored. Here, we propose an NFTPV system that utilizes calcite (CaCO₃) covered with black phosphorus (BP) as the emitter and InSb as the photovoltaic cell. The proposed structure significantly enhances the performance of NFTPV compared to the structure without BP, achieving an output power of 3.23 × 10⁵ W/m² and efficiency of 42.6 % at an emitter temperature of 900 K. The improvement in performance is attributed to the frequency matching between the radiation spectrum of emitter and interband transition of InSb, where the coupling of hyperbolic resonances in CaCO₃ and surface plasmon modes in BP plays an important role. Moreover, we found that the performance will be further improved when the CaCO₃ thickness is small. In addition, the sandwich structure BP/CaCO₃/BP-InSb is also a desirable alternative solution. This study would be beneficial for understanding the role of resonant coupling and provides a new strategy to improve the performance of NFTPV systems.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"211 ","pages":"Article 109712"},"PeriodicalIF":4.9,"publicationDate":"2025-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138699","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":"Dynamics of cavitation bubble collapse in isothermal and cryogenic fluids: Influence of condensable and non-condensable gases","authors":"Eslam Ezzatneshan,&nbsp;Alireza Akbari","doi":"10.1016/j.ijthermalsci.2025.109710","DOIUrl":"10.1016/j.ijthermalsci.2025.109710","url":null,"abstract":"<div><div>This study investigates the dynamics of cavitation bubble collapse near a solid surface, considering the compressibility of both liquid and gas phases and the impact of mass transfer. Validation of the numerical method against Rayleigh's analytical solution shows good agreement, affirming the method's accuracy. The study demonstrates that cavitation bubbles containing condensable fluids (vapor) collapse more rapidly than those containing non-condensable fluids (air). Specifically, the hydrogen vapor bubble collapses significantly faster than the water vapor bubble. Three primary pressure peaks are identified during the collapse: an expansion pressure wave (EPW), a jet pressure wave (JPW), and reflected pressure waves (RPW). Among these, the JPW is the most intense for all bubbles studied. The collapse of hydrogen vapor bubbles, despite higher jet velocities, results in lower surface pressure stress due to the lower density of liquid hydrogen compared to water. In contrast, the air bubble produces lower jet velocity and less surface pressure stress due to the cushioning effect of non-condensable air. The study also explores the effects of bubble distance from the wall and surface wettability. It is found that greater distances result in lower pressure impacts on the surface, and hydrophobic surfaces cause bubbles to collapse closer to the surface, increasing the impact. Quantitative results indicate that while varying surface wettability has a significant effect on water vapor bubble collapse, it has a minimal impact on the collapse of hydrogen vapor and air bubbles due to the dominant damping effects of gas and rapid collapse dynamics of hydrogen vapor.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"211 ","pages":"Article 109710"},"PeriodicalIF":4.9,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138700","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":"Reliable determination of convective heat transfer coefficients as fluid flows through rock fractures","authors":"Luanluan Xue ,&nbsp;Yulong Han ,&nbsp;Wujun Qian ,&nbsp;Lichun Jiang ,&nbsp;Wenji Su ,&nbsp;Yucheng Zhang ,&nbsp;Xuelian Deng ,&nbsp;Isam Shahrour","doi":"10.1016/j.ijthermalsci.2025.109709","DOIUrl":"10.1016/j.ijthermalsci.2025.109709","url":null,"abstract":"<div><div>During heat-mining of earth's stored thermal energy, low-temperature fluids are injected into hot dry rock, forcing convective heat transfer between the fluid and the rock fracture. The convective heat transfer coefficient (HTC) is a crucial parameter characterizing the intensity of convective heat transfer, which affects heat influx into the fluid. Generally, HTC is obtained experimentally or determined by analytical methods dependent on measured outlet fluid temperatures, both of which are difficult to apply in practical geothermal engineering. Based on the boundary layer theory, an innovative analytical method for determining the HTC is proposed. It assumes that heat exchange near the fracture surface occurs mainly via heat conduction in the viscous sublayer. The HTC is independent of rock block properties, but depends on fracture aperture, fluid velocity, fluid thermal conductivity, fluid kinematic viscosity, and surface roughness. This method allows the HTC to be obtained dynamically, thus improving the precision of the calculated convective heat transfer process, and it can also be easily utilized in prospective geothermal simulations. The reliability of this method was well verified by comparing its numerical results with 78 experimental results. The proposed method also performed well when applied in numerical simulations of heat transfer within rock masses containing intersecting fractures. The simulations indicated that the HTC is influenced by both fracture aperture and fluid velocity, resulting in the changes in temperature distributions after intersections of fractures. Therefore, the HTC should be determined dynamically in heat transfer simulations using the local thermal non-equilibrium model, otherwise, large errors in the temperature distributions of fractured rock masses may occur.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"211 ","pages":"Article 109709"},"PeriodicalIF":4.9,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138702","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":"Optimization and evaluation of porous ablative composites driven by porosity distribution using neural networks","authors":"Hai-Bo Xu,&nbsp;Lin Tian,&nbsp;Zeng-Yao Li","doi":"10.1016/j.ijthermalsci.2025.109714","DOIUrl":"10.1016/j.ijthermalsci.2025.109714","url":null,"abstract":"<div><div>In aerospace applications, the thermal protection system (TPS) plays a pivotal role in safeguarding high-speed vehicles and spacecraft from extreme heat. Porous ablative composites, commonly used in TPS, mitigate overheating and structural failure through heat absorption and dissipation. However, current approaches to optimizing the thermal protection performance of these composites often rely on random or heuristic porosity distributions, which lack systematic design frameworks. This study introduces a method for optimizing the thermal protection performance of porous ablative composites by integrating neural network models with optimization algorithms. The results demonstrate that an optimized two-section porosity scheme with higher porosity near the heated surface significantly improves thermal protection, reduces bondline temperature by 21.88 K compared to traditional designs, which accounts for 11.49 % of the temperature rise. Additionally, the optimized composite exhibits 6.5 % reduced equivalent density, offering an efficient solution with superior thermal protection. The study also finds that smoothing the porosity transition zone does not improve performance and adds unnecessary manufacturing complexity. These findings provide a robust framework for future design of porous ablative composites, enabling more efficient and cost-effective solutions for high-speed aerospace missions.</div></div>","PeriodicalId":341,"journal":{"name":"International Journal of Thermal Sciences","volume":"211 ","pages":"Article 109714"},"PeriodicalIF":4.9,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143138060","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}