Article
Thermodynamics
Xin Gu, Menghong Li, Wei Gao, Qiming Shi
Summary: A full-section periodic model of torsional flow heat exchanger with orthogonal elliptical tubes has been established, and the heat and flow transfer on the tube and shell sides have been numerically simulated. Compared with round tubes, the orthogonal elliptical tubes showed improved convective heat transfer coefficient and comprehensive performance. On the shell side, the heat transfer coefficient increased while the pressure drop decreased, resulting in improved comprehensive performance.
APPLIED THERMAL ENGINEERING
(2023)
Article
Environmental Sciences
Pedram Rezaei, Hamid Reza Moheghi, Amin Amiri Delouei
Summary: This paper focuses on the fabrication and optimization of a spiral-tube heat exchanger (STHE) to improve the heat transfer rate and efficiency of traditional instantaneous water heaters. The large number of exported instantaneous water heaters from Garman Gas Toos company has caused significant cost and credit reduction due to corrosion and leakage. The high energy consumption also justifies the need for a new STHE design. The main innovation of this research is the development of a smaller and more efficient heat exchanger by identifying the factors that affect its efficiency and heat transfer rate.
Article
Thermodynamics
Changgui Xie, Gongxing Yan, Qiong Ma, Yasser Elmasry, Pradeep Kumar Singh, A. M. Algelany, Makatar Wae-hayee
Summary: This study proposes a method using response surface methodology (RSM) and artificial neural network (ANN) to optimize the design of fin-tube heat exchangers (FTHEs) with vortex generators (VGs). The results show that ANN outperforms RSM in predicting the Nusselt number and the friction factor.
CASE STUDIES IN THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Jingyu Cui, Mingjun Li, Weigang Xu, Zhe Lin, Linhang Zhu, Yuzhen Jin
Summary: This study develops an improved particle deposition model and investigates the fouling reduction performance of elliptical tube bundles under different conditions. The findings reveal that elliptical tube bundles can effectively reduce operational resistance and ash fouling in flue gas heat exchangers, especially at large eccentricities and low flue gas velocity.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Ahmet Umit Tepe, Harun Yilmaz
Summary: This study numerically investigated the heat transfer performance of circular-slice-shaped-winglet for tube bank heat exchanger. The optimal design was obtained by analyzing various geometric parameters. The results showed that the CSSW winglet design significantly improved the performance of the heat exchanger.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Multidisciplinary Sciences
Sohan Lal Sharma, Satyendra Singh, Ajoy Debbarma, Kuber Singh Mehra
Summary: The thermohydraulic performance of a heat exchanger can be improved using passive methods with different insert geometries. This experimental study investigated the effect of a perforated solid hollow elliptical insert on the overall performance of a circular tube heat exchanger, and found that the insert significantly increased heat transfer within a certain range of Reynolds numbers.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2023)
Article
Thermodynamics
Hawatchai Keawkamrop, Lazarus Godson Asirvatham, Ahmet Selim Dalkilic, Ho Seon Ahn, Omid Mahian, Somchai Wongwi
Summary: This study experimentally investigates the performance of crimped spiral fin-and-tube heat exchangers with a small tube diameter. The results show that the fin pitch and outer diameter have significant effects on the heat transfer characteristics and friction factor. Correlations between the Nu, j, and f are proposed for designing heat exchangers in the thermal industry.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
S. A. Marzouk, M. M. Abou Al-Sood, Magda K. El-Fakharany, Emad M. S. El -Said
Summary: This study presents a numerical modeling of shell and tube heat exchangers with various baffle configurations, and it was found that the hybrid and circular ring baffles have the most significant impact on improving thermal and hydraulic performance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Thermodynamics
Ali Akbar Abbasian Arani, Hamed Uosofvand
Summary: By comparing different baffle and tube bundle configurations in this study, it was found that angled-elliptical tube bundles performed better in terms of efficiency. For SPHB, the EEC was improved by 20.9% and 10.7% with angled-elliptical tube bundles compared to horizontal and vertical arrangements. Similar trends were observed for DPHB and DPCHSB configurations.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Engineering, Chemical
Han-Taw Chen, Ming-Hsun Hsu, Kai-Chen Yang, Kuei-Hao Chang, Kuo-Chi Liu
Summary: This study predicts heat transfer using an inverse CFD method and selects an appropriate flow model through validation tests. The study finds the presence of vortex rings in the low-velocity region of the tubes and the inclination of thermal plumes varies with the diameter. The experimental results agree with theoretical models.
JOURNAL OF THE TAIWAN INSTITUTE OF CHEMICAL ENGINEERS
(2022)
Article
Thermodynamics
Heeseung Kang, Ukmin Han, Hongyoung Lim, Hoseong Lee, Yunho Hwang
Summary: A novel polymer bare-tube heat exchanger (BTHX) with improved thermal-hydraulic performance compared to a target aluminum louvered-fin micro-channel heat exchanger (MCHX) is proposed in this paper. The optimized polymer BTHX shows 91.5% and 134.9% of the MCHX performance respectively, mainly due to enhanced air-side heat transfer coefficient. The unique structure of the sinusoidal wavy tube in the proposed BTHX reduces air-side pressure drop and promotes air flow mixing to improve convective heat transfer.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Lijin Chen, Shuai Deng, Ruikai Zhao, Yu Zhu, Li Zhao, Shuangjun Li
Summary: CO2 adsorption technology, especially temperature swing adsorption (TSA), is crucial in reducing carbon dioxide emissions and achieving carbon neutrality. This study examined the thermal design schemes based on single-tube/three-tube heat exchanger in adsorption bed, finding that the three-tube heat exchanger outperforms the single-tube heat exchanger in energy efficiency performance under the same conditions. The findings are beneficial for optimizing the geometric structure and operation strategy of the adsorption bed in TSA system.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Arun Kumar Tiwari, Summaiya Javed, Hakan F. Oztop, Zafar Said, Naimish S. Pandya
Summary: This study investigated a novel design called Triple Tube Heat Exchanger to enhance overall heat transfer and effectiveness by using WO3/water nanofluid and various inserts. The results demonstrated significant thermal performance improvement with rib-type insert in both experimental and computational fluid dynamics methods.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Article
Thermodynamics
Ali Akbar Abbasian Arani, Hamed Uosofvand
Summary: Numerical investigation on laboratory-scale segmental baffles shell-and-tube heat exchanger reveals that twisted oval tubes with segmental baffles can significantly reduce pressure drop and improve heat transfer compared to circular and elliptical tube bundles. The STHX with twisted oval tube bundles and segmental baffle exhibits the highest efficiency evaluation coefficient (EEC) value equal to 1.16 among all investigated models.
INTERNATIONAL JOURNAL OF NUMERICAL METHODS FOR HEAT & FLUID FLOW
(2021)
Article
Thermodynamics
Ahmet Talat Inan, Hasan Koten, Mehmet Akif Kartal
Summary: This study investigates the impact of different designs of baffle plates on the thermal efficiency and hydraulic performance of shell-tube heat exchangers. The design geometry was analyzed using the ANSYS Fluent program. The results show variations in heat transfer rates per drop of pressure compared to traditional one-piece baffle plates and perforated type baffle plates.
INTERNATIONAL JOURNAL OF LOW-CARBON TECHNOLOGIES
(2022)
Article
Thermodynamics
Yunxia Ma, Fei Liu, Honggang Pan, Hongjian Zhang, Shuxia Yan, Ailing Zhang
Summary: This paper proposes a dynamically tunable and switchable perfect infrared absorber that exhibits excellent electrical regulation performance and high absorptance. The absorption mechanism is explained using a multiple interference model, and it is proven to be polarization insensitive.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
F. J. dos Santos, G. S. M. Martins, M. Strobel, L. Beckedorff, K. V. de Paiva, J. L. G. Oliveira
Summary: This study investigates the effects of inlet conditions and plate's features on the thermal-flow performance of a gasket plate heat exchanger (GPHE) and assesses the impact of a modified tightening distance on its performance. No systematic study on the combined effects of inlet conditions and assembly accuracy on GPHE performance has been conducted before.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Alok K. Ray, Dibakar Rakshit, K. Ravi Kumar, Hal Gurgenci
Summary: The low thermal conductivity of phase change materials limits the heat transfer rate and application of latent heat storage systems. This numerical study examines the impact of two passive heat transfer enhancement techniques on the thermal performance of a latent heat storage system. The results show that the orientation and position of the heat transfer fluid tube have significant effects on the charging duration, while the discharging duration remains unchanged. The combined effect of orientation and eccentricity reduces the charging duration, but increases the discharging duration compared to the concentric domain.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Yalu Han, Yanlong Wang, Chenyang Liu, Xinmin Hu, Yin An, Zhengcai Li, Jiaxun Jiang, Lizhi Du
Summary: This paper investigates the calculation method of thermal conductivity in NAPLs-contaminated soils. By establishing NAPLs-contaminated soil models and using the Lattice Boltzmann Method (LBM) for calculation, an optimized three-dimensional model with high computational accuracy and efficiency is obtained. The study also finds that saturation and Nz parameters have a significant impact on calculation time, while the thermal conductivity of the two-dimensional model is more sensitive to anisotropy. The influence of porosity and NAPLs content on thermal conductivity should be considered during in-situ thermal desorption.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Mostafa Taha, Song Zhao, Aymeric Lamorlette, Jean-Louis Consalvi, Pierre Boivin
Summary: For the first time, large-eddy simulations (LES) of the near-field region of large-scale fire plumes were performed using a pressure-based Lattice Boltzmann method (LBM) with low-Mach number approximation. The simulations showed quantitative agreement with experimental data and were consistent with previously-published numerical studies. The study demonstrated the computational efficiency of the proposed LBM solver in tackling fire-induced flows, suggesting LBMs as a good alternative candidate for modeling fire-related problems.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Weixin Zhang, Yehang Xie, Yuqiang Ding, Zhao Liu, Zhenping Feng
Summary: This study investigated the impact of upstream slot leakage on the endwall film cooling characteristics of turbine blades. Pressure Sensitive Paint (PSP) technology was used to measure the film cooling characteristics, and numerical analysis was conducted to evaluate the aerodynamic performance. It was found that increasing the mass flow ratio of the upstream slot enhanced film cooling, decreased aerodynamic losses, and reduced the strength of passage vortex. However, reducing the distance between the slot and the blade leading edge only enhanced film cooling without affecting the leakage coverage area.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Rui Zhang, Zhen-lei Li, Yan-sheng Zhang, Dong Chen, Guo Yuan
Summary: This study discusses the heat transfer behavior of different jet forms on steel tubes. The results show that the annular jet performs better in terms of cooling intensity and uniformity. The cooling performances of the two jet forms are similar when the steel tube size is small. Therefore, the planar jet can be considered for smaller diameters due to its simplicity, low cost, and convenience in application.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
A. R. Khoei, A. M. Orvati Movaffagh, A. Rezaei Sameti
Summary: This paper presents a comprehensive study on the thermo-mechanical characteristics of oxide-coated aluminum nano-powder. It is found that the thermal conductivity of oxide-coated aluminum nano-powder is significantly lower than that of the bulk aluminum, and it is affected by the density and temperature.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Yanjin Wang, Jintao Xiong, Lingyu Chen, Zhihai Lv, Qian Wang
Summary: A solar radiation transfer model for spray cooling double skin facade (SC-DSF) is proposed in this study. The model is validated by experimental results and various influence factors are analyzed. The effectiveness of adjusting droplet coverage rate and size is also evaluated.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Bostjan Zajec, Blaz Mikuz, Anil Kumar Basavaraj, Marko Matkovic, Matej Tekavcic, Martin Draksler, Leon Cizelj, Bostjan Koncar
Summary: We have developed an advanced experimental setup to investigate flow and heat transfer in an annular channel. The setup allows heat transfer measurements and flow visualization using a temperature-controlled inner tube. Measurements can be conducted in both single-phase and two-phase flow regimes. The setup ensures a uniform velocity field in the annular channel using specially designed inlet and outlet headers. The inner copper tube is heated by water and contains turbulators for enhanced heat transfer and thermocouples for temperature measurement. A three-dimensional conjugate heat transfer CFD model has been developed and validated to accurately estimate heat losses in the setup. This study demonstrates the importance of numerical simulations in improving the interpretation of complex experimental results.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Weijie Chen, Ke Wang, Yongqing Wang, Shantung Tu, Zunchao Liu, Huijuan Su
Summary: In this study, a novel gradient porosity transpiration cooling plate structure (GP-TCPS) is proposed to alleviate heat transfer deterioration caused by non-uniform temperature distribution in transpiration cooling plate structure (TCPS). Computational fluid dynamics (CFD) and response surface method (RSM) were used for qualitative and quantitative analysis of the flow and heat transfer of GP-TCPS. The optimized structure of GP-TCPS significantly improves temperature uniformity, injection pressure, and average cooling efficiency compared to traditional TCPS.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
R. Essam, A. Elsaid, W. K. Zahra
Summary: This study presents a novel bioheat model for simulating heat transfer in skin tissue. The model offers an improved representation of thermal dynamics in the skin and has been validated using numerical solutions and experimental measurements. The study highlights the importance of incorporating vascular inlet parameters and thermal relaxation effects in the thermal profile, and suggests potential applications in thermal therapy and wound healing.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Dongbo Shi, Tao Xu, Zifeng Chen, Di Zhang, Yonghui Xie
Summary: The cooling structure design of turbine blades is crucial for the safety and reliability of the gas turbine set. This research investigates different arrangement schemes, including dimple/protrusion arrangements, to enhance the cooling performance. The results show that the arrangement scheme with both passes arranged by dimples has the best comprehensive thermal performance.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Emrehan Guersoy, Hayati Kadir Pazarlioglu, Mehmet Guerdal, Engin Gedik, Kamil Arslan
Summary: The thermo-hydraulic performance of Al2O3/H2O nanofluid with different nanoparticle shapes flowing in a sudden expansion tube with variable sudden expansion inclination angles and elliptical dimpled fins with different diameters were numerically investigated. The results showed that the nanoparticle shapes, sudden expansion inclination angles, and elliptical dimpled fin have significant impact on the thermo-hydraulic performance. This study reveals the novelty and importance of these factors in the research.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)
Article
Thermodynamics
Rukun Hu, Xinyu Huang, Xinyu Gao, Liu Lu, Xiaohu Yang, Bengt Sund
Summary: This study examines the impact of applying bottom cross-cut on PCM's spatial distribution in a horizontal LHTES unit using numerical simulation. The findings show that bottom cross-cut can improve the heat storage rate and natural convection heat transfer gain.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2024)