International Journal of Heat and Fluid Flow最新文献

{"title":"Pseudo three-dimensional topology optimization of chip heat sinks with various inlet–outlet arrangements","authors":"Jin Huang ,&nbsp;Wanting Li ,&nbsp;Bohao Chen ,&nbsp;Kai Jiao ,&nbsp;Qiuwang Wang ,&nbsp;Cunlu Zhao","doi":"10.1016/j.ijheatfluidflow.2024.109670","DOIUrl":"10.1016/j.ijheatfluidflow.2024.109670","url":null,"abstract":"<div><div>Topology optimization (TO) represents a significant advancement in heat sink design for microelectronic chips. Although two-dimensional (2D) TO is favored for its simplicity and lower computational cost, it lacks the accuracy of three-dimensional (3D) TO, omitting certain processes inherent to 3D models. This paper introduces a novel pseudo 3D TO model, which integrates a 2D thermo-fluid design layer with a 2D conductive base plate layer, specifically optimized for chip heat sink designs. Employing the variable density method, we establish a mathematical description of the pseudo 3D TO, incorporating governing equations for flow dynamics and temperature variations in both layers. A distinctive feature of this model is its consideration of thermal coupling in the dimension typically neglected by standard 2D TO models. We applied the pseudo 3D TO model to optimize heat sink structures across various inlet and outlet configurations, followed by rigorous analyses to compare flow and heat transfer performances. These comparisons offer critical insights into the advantages and trade-offs of each configuration. Ultimately, a 3D heat sink was reconstructed from the pseudo 3D optimization results, and a detailed numerical experiment was conducted to assess its thermal performance under realistic conditions, thereby validating the efficacy and reliability of the pseudo 3D TO model. The findings underscore the model’s potential in achieving efficient and practical heat sink designs, balancing accuracy and computational efficiency.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"111 ","pages":"Article 109670"},"PeriodicalIF":2.6,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Preparation and characterization of modified steel slag-based composite phase change materials","authors":"Chenhao Yang ,&nbsp;Zekai Zhang ,&nbsp;Haowen Yu ,&nbsp;Nian Xu ,&nbsp;Zucun Rui ,&nbsp;Huaqiang Chu","doi":"10.1016/j.ijheatfluidflow.2024.109666","DOIUrl":"10.1016/j.ijheatfluidflow.2024.109666","url":null,"abstract":"<div><div>In order to promote the resource utilization in steel slag and reduce the environmental hazards caused by steel slag, a steel slag-based composite phase change material was prepared in this experiment. Steel slag had a porous structure with good structural stability, which could be used to prepare composite phase change materials and applied in fields such as thermal energy storage and waste heat recovery. To enhance the adsorption capacity of steel slag on phase change materials, the impact of acid or alkali modifiers on steel slag was meticulously examined. The investigation revealed that the pore structure of the modified steel slag was markedly enhanced, accompanied by a notable improvement in adsorption capacity. Among the results, the adsorption rate of the acid washed modified steel slag for paraffin reached 35 %, with the phase change temperature and latent heat of phase change being 53 °C and 60 J/g. Acid washing had a significant impact on the pore structure of the steel slag, with the adsorption rate of the acid washed modified steel slag for paraffin being approximately twice that of the unmodified steel slag.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"111 ","pages":"Article 109666"},"PeriodicalIF":2.6,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hydrothermal performance enhancement of heat sink using low flow-drag twisted blade-like fins","authors":"Shoutong Ji,&nbsp;Cairang Huadan,&nbsp;Pan Qi,&nbsp;Zhenwei Liu,&nbsp;Ping Li","doi":"10.1016/j.ijheatfluidflow.2024.109669","DOIUrl":"10.1016/j.ijheatfluidflow.2024.109669","url":null,"abstract":"<div><div>To prevent power equipment from breaking down due to overheating, an innovative design of twisted blade-like fins for heat sinks is proposed to enhance heat transfer efficiency and minimize pressure drop. The effects of the twist angle and different NACA airfoil cross-section of fins on the flow and heat transfer characteristics are investigated using numerical simulation methods over a Reynolds number range of 8548 to 34194. Comparing the twisted blade-like fins with cylindrical fins, the relative Nusselt number is 1.067–1.397, the relative friction coefficient is 0.528–1.339, and the hydrothermal performance factor (<em>HTPF</em>) is 1.155–1.552. The results demonstrate that the novel twisted blade-like fins substantially outperform cylindrical fins in terms of comprehensive thermal performance. Furthermore, the optimal design in the study is compared with the best design in similar studies, and the results show that the optimal twisted blade-like fins exhibit better advantages in drag reduction performance and <em>HTPF</em>. When Reynolds number is 34194, the twisted blade-like fins provide the highest <em>HTPF</em> of 1.552. The twisted blade-like fins stimulate spanwise and normalwise secondary flow, promoting fluid exchange between the wall and the channel core, thereby enhancing the heat transfer performance of the heat sink. Increasing the twist angle will improve heat transfer efficiency but increase pressure drop. Different cross-section shape can have different effects, and using NACA0009 airfoil cross-section yields better results in most cases. The twisted blade-like fins are effective in the field of heat transfer enhancement with low flow resistance of streamlined structure and strong heat transfer effect of secondary flow, greatly improving the comprehensive thermal performance of the heat sink.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"111 ","pages":"Article 109669"},"PeriodicalIF":2.6,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermal-hydrodynamic analysis for internally interrupted-finned tubes: Experimental, numerical and performance study","authors":"O.H. Salem,&nbsp;Ahmed Hegazy,&nbsp;K. Yousef","doi":"10.1016/j.ijheatfluidflow.2024.109665","DOIUrl":"10.1016/j.ijheatfluidflow.2024.109665","url":null,"abstract":"<div><div>The characteristics of fluid flow and heat transfer in an internally interrupted-finned tube were studied, experimentally and numerically, and a performance evaluation study was conducted in the present research. The numerical results were validated with the current experimental data as well as other published data, with a maximum deviation of 8.93 %. The effect of different key parameters like fin height, number of fin-rows, fin thickness and number of fins in each row on the thermal-hydrodynamic performance was explored. This study reveals that increasing both fin height and number of fin-rows raises the heat transfer coefficient and friction factor values, but fin thickness negligibly affects the performance. Notably, the average heat transfer coefficient value rises by 25.03 % if the fin height to diameter ratio is increased from 0.1786 to 0.4018, and by 21.4 % if the number of fins is increased from 2 to 6, compared to finless tubes under a mass flow rate of 0.39 kg/s, for three number of fins per row. Compared to the continuously finned tubes, the interrupted-finned tubes have higher heat transfer coefficient values if the interruption length is equal to or less than the fin length, while these values are reduced below that of the continuously finned if the interruption length is larger than the fin length. Clearly, when the interruption length is 3 times the fin length, the heat transfer coefficient value of the continuously finned tube is higher than that of the interrupted-finned one by 3.1 %, while the heat transfer coefficient value of the interrupted-finned tube is higher than that of the continuously finned one by 13.59 %, when the interruption length is reduced to one-third of the fin length. It is recommended using the interrupted-finned tubes over the smooth ones if the amount of mass flow rate flowing through both tubes is the same, but the use of interrupted-finned tubes is not recommended as opposed to smooth ones if both tubes are subjected to the same pressure drop across them.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"111 ","pages":"Article 109665"},"PeriodicalIF":2.6,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modulation of the local mass and heat transfer of turbulent double-diffusive convection under stable thermal stratifications","authors":"S. Kenjereš ,&nbsp;R. Roovers","doi":"10.1016/j.ijheatfluidflow.2024.109636","DOIUrl":"10.1016/j.ijheatfluidflow.2024.109636","url":null,"abstract":"<div><div>We report on numerical studies of bounded double-diffusive turbulent convection, which involves the combined effects of concentration/solutal and thermal buoyancy forces. Our study focuses on an intermediate range of the characteristic non-dimensional numbers, specifically <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>7</mn></mrow></msup><mo>≤</mo><msub><mrow><mi>Ra</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>≤</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>9</mn></mrow></msup></mrow></math></span>, and <span><math><mrow><mn>0</mn><mo>≤</mo><msub><mrow><mi>Ra</mi></mrow><mrow><mi>θ</mi></mrow></msub><mo>≤</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>6</mn></mrow></msup></mrow></math></span>. We use fixed values for the concentration and temperature Prandtl numbers (i.e. <span><math><mrow><msub><mrow><mi>Pr</mi></mrow><mrow><mi>c</mi></mrow></msub><mo>=</mo><mn>700</mn></mrow></math></span>, <span><math><msub><mrow><mi>Pr</mi></mrow><mrow><mi>θ</mi></mrow></msub></math></span> = 7), which approximately correspond to seawater properties. We apply wall-resolved Large Eddy Simulations (LES) and compare the obtained results with available Direct Numerical Simulations (DNS) in the literature. Our findings show an overall good agreement in predicting the global wall mass and heat transfer coefficients, achieved with significantly reduced computational costs. Furthermore, the local mass and heat transfer distributions reveal a high sensitivity to the strength of the vertically imposed stable thermal stratification. Finally, we present the vertical profiles of the long-term time-averaged first and second moments.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"111 ","pages":"Article 109636"},"PeriodicalIF":2.6,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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":"Visual boiling experimental research based on lateral liquid supply structure","authors":"Fei Li,&nbsp;Guodong Xia,&nbsp;Ran Li","doi":"10.1016/j.ijheatfluidflow.2024.109664","DOIUrl":"10.1016/j.ijheatfluidflow.2024.109664","url":null,"abstract":"<div><div>The high heat transfer coefficient and critical heat flux density of thin liquid film boiling provide new ideas for enhancing boiling heat transfer, but the bottom-up liquid supply method limits its further application and development. This study is based on the experimental research results of previous researchers and adds lateral liquid supply while maintaining a lower liquid level. And thin liquid film boiling experiments were conducted on the surface of silicon under low subcooling conditions (subcooling degree: 5 K). The obtained curves were compared with the results of smooth copper surface in pool boiling experiments. Among them, thin liquid film boiling exhibits excellent HTC and higher CHF (12.26 W/cm²·K and 191.63 W/cm², respectively). Then, the bubble behavior and flow characteristics of thin liquid film boiling bubbles were visualized and the heat transfer mechanism was analyzed. The experimental results indicate that the lateral liquid supply boiling structure designed in this study has great potential for application.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"111 ","pages":"Article 109664"},"PeriodicalIF":2.6,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705951","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of inclined magnetic field on mixed convective cross flow across a cylinder with uniform heat flux condition","authors":"Rupam Saha,&nbsp;B. Hema Sundar Raju","doi":"10.1016/j.ijheatfluidflow.2024.109648","DOIUrl":"10.1016/j.ijheatfluidflow.2024.109648","url":null,"abstract":"<div><div>This numerical study delves into the interplay between inclined magnetohydrodynamic flow and mixed convective heat transfer in a cylindrical geometry under uniform heat flux condition. The study employs a quasi-static model, where the fluid is flowing in a cross-stream regime, satisfies the Boussinesq approximation. A higher-order finite difference scheme is adopted to discretize the non-linear Navier–Stokes and energy equations, followed by a stable pseudo-time iterative technique. This study reveals that a lower Richardson number and interaction parameter are sufficient to induce vortex shedding under positive magnetic angles that can not be achieved in case of aligned magnetic field. Increasing the strength of magnetic field tends to restore the symmetric flow structure from the buoyancy-driven asymmetric one, contingent upon the magnetohydrodynamic flow orientations. The coefficients of viscous and pressure drag, average Nusselt number become non-monotonic for the aligned magnetic field, whereas it becomes strictly monotonic for other positive magnetic inclination angles at each Richardson number. Interestingly, increasing magnetic inclination angle allows to augment the total drag coefficient and overall heat transfer drastically. Critical interaction parameter is determined for average Nusselt number at various Richardson and Reynolds numbers under aligned magnetic field. The heat transfer is significantly more enhanced under uniform heat flux condition compared to constant wall temperature condition. The enhanced heat transfer achieved through magnetic field integration and modified thermal conditions has significant potential for applications such as electronic cooling, solar collectors, material processing, and more.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"111 ","pages":"Article 109648"},"PeriodicalIF":2.6,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on flow non-uniformity and design of tapered manifold inlet structure of manifold microchannels","authors":"Yuan-Sheng Lin ,&nbsp;Kai Chen ,&nbsp;Han-Bing Ke ,&nbsp;Yong-Hui Xie","doi":"10.1016/j.ijheatfluidflow.2024.109645","DOIUrl":"10.1016/j.ijheatfluidflow.2024.109645","url":null,"abstract":"<div><div>Effective cooling of electronic equipment in the integrated control system is critical. Manifold microchannel (MMC) liquid cooling technology has many advantages, but the non-uniform distribution of coolant limits its heat transfer performance. This study analyzed the non-uniformity of MMC heat sinks through numerical simulations. A tapered manifold inlet structure was proposed to improve flow uniformity. Additionally, since numerical simulations are computationally intensive, a temperature prediction method for MMC heat sink based on a reduced-order model was proposed. The results show that the tapered manifold inlet structure can improve the flow uniformity, and the improvement is more obvious with the increase of the taper angle. The average relative error (<em>RE</em>) and the average maximum absolute error (<em>MAE</em>) of the reduced-order model are 0.00406 % and 0.78 K respectively, which indicates that the reduced-order model can predict the temperature distribution of MMC heat sink quickly and accurately.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"110 ","pages":"Article 109645"},"PeriodicalIF":2.6,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 study on dynamic flow and heat transfer performance of silicon-based microchannel under variable thermal load","authors":"Meiyong Li ,&nbsp;Yunyi Wang ,&nbsp;Ding Wang ,&nbsp;Jiayu Wang ,&nbsp;Limei Shen","doi":"10.1016/j.ijheatfluidflow.2024.109663","DOIUrl":"10.1016/j.ijheatfluidflow.2024.109663","url":null,"abstract":"<div><div>The issue of high power density in chips has become one of the bottlenecks restricting the improvement of chip performance. Silicon-based microchannel heat sinks (Si-MCHS) can guide the cooling fluid close to the chip junction, significantly enhancing the cooling capability. Due to the rapid changes in chip power consumption, understanding the flow and heat transfer performance of Si-MCHS, especially their dynamic heat transfer performance, is crucial. This paper introduces the fabrication of Si-MCHS and experimentally tests its static and dynamic performance. The microchannels can handle a maximum thermal flux of 71.3 W/cm2. It was found that the temperature response process of Si-MCHS mirrors that of a first-order system’s step response or zero-input response. Upon a sudden change in power consumption, the thermal response can reach 90 % of the steady-state temperature difference (Δ<em>T</em>) within 4 s and 50 % Δ<em>T</em> within 1 s. Increasing the pump speed significantly reduces the response time, while different power step changes have minimal impact on the response time. Consequently, we have formulated a graded flow rate control strategy based on the flow and heat transfer performance of Si-MCHS, which achieves effective flow rate control.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"110 ","pages":"Article 109663"},"PeriodicalIF":2.6,"publicationDate":"2024-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142699323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 MOPSO-based design optimization on molten salt steam generator forced circulation system under off-design conditions","authors":"Jiaming Tian,&nbsp;Biao Li,&nbsp;Bo Ren,&nbsp;Yueshe Wang","doi":"10.1016/j.ijheatfluidflow.2024.109659","DOIUrl":"10.1016/j.ijheatfluidflow.2024.109659","url":null,"abstract":"<div><div>The concentrating solar power (CSP) technologies have been demonstrated their effectiveness in providing ancillary services for peak regulation in power systems with high penetration of renewable energy. Investigating control mechanisms of a forced circulation mode applied in the steam generator, which a shell-and-tube heat exchanger, in the CSP plant is imperative for swift adaptation to its off-design operating conditions. This study aims to develop a predictive model for the hydrodynamics of a molten salt steam generator in a forced circulation mode, integrating heat transfer and phase change through the lumped parameter method. Additionally, a solution approach is proposed based on multi-objective particle swarm optimization (MOPSO) to achieve thermal-economic optimization designs of the steam generator under varying off-design conditions. Optimization analyses are conducted separately for the constant load and the off-design conditions, considering variables such as molten salt flow rate, steam-water circulation flow rate, number of baffles, and tube diameter of the heat exchanger. The results reveal that during the prolonged operation at low evaporation rates, employing an evaporator with more baffles and a larger tube diameter of 20 mm leads to favorable outcomes. Conversely, meticulous design considerations are imperative when planning for sustained high evaporation rates due to the significant impact of the number of baffles on both efficiency and economic costs. At a load of 215 t/h, the adding of two baffles results in an approximate increase of $20 million in operational costs by nearly and an improvement in efficiency by 0.01. Additionally, a fitting formula is provided to offer recommendations on optimal mass flow rates that maximize effectiveness and minimize economic costs for varying evaporation demands under off-design conditions, thereby assisting engineers in optimizing peak regulation operations.</div></div>","PeriodicalId":335,"journal":{"name":"International Journal of Heat and Fluid Flow","volume":"110 ","pages":"Article 109659"},"PeriodicalIF":2.6,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}