International Journal of Thermofluids最新文献

{"title":"A review of hydrogen generation methods via aluminum-water reactions","authors":"Nicola Musicco ,&nbsp;Marcello Gelfi ,&nbsp;Paolo Iora ,&nbsp;Matteo Venturelli ,&nbsp;Nancy Artioli ,&nbsp;Luca Montorsi ,&nbsp;Massimo Milani","doi":"10.1016/j.ijft.2025.101152","DOIUrl":"10.1016/j.ijft.2025.101152","url":null,"abstract":"<div><div>This article presents a comparison of the various methodologies reported in the literature to generate hydrogen through the reaction between aluminum powders and water. This reaction, however, is hindered by the surface oxide layer, which prevents direct contact between pure aluminum and water. The low cost of aluminum, its infinite recyclability, and the potential to carry out the reaction in an environmentally sustainable manner make it a promising material for hydrogen production. Given the critical need to address the limitations of hydrogen storage and transportation, as well as to accelerate the adoption of hydrogen as an energy carrier for the energy transition, this comparison focuses on the two most environmentally promising methodologies: ball milling and steam oxidation methodologies.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"27 ","pages":"Article 101152"},"PeriodicalIF":0.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143576852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Photothermal analysis of novel nanoparticles-laden fluid-based solar thermal receiver: A proof-of-concept experimental study","authors":"J.S.D. Nandini ,&nbsp;Vishal Bhalla ,&nbsp;Himanshu Tyagi","doi":"10.1016/j.ijft.2025.101158","DOIUrl":"10.1016/j.ijft.2025.101158","url":null,"abstract":"<div><div>Excessive extraction of fossil fuels leads to air pollution, water pollution, destruction of habitat, etc., which are some of the severe environmental consequences. Directing towards renewable energy sources like solar and wind energy helps to attenuate these impacts and promote a purified, healthier environment for future generations. Solar energy is infinitely available and used for present and future energy needs. Thus, by utilizing this power, we can mitigate the carbon footprint, greenhouse gas (GHG) emissions, etc., which helps to build a secure, clean energy future. This experimental study compared the photo-thermal effects of surface absorption and nanoparticle-laden systems on the moving flow characteristics of the nanoparticle-laden fluid in a novel spiral solar collector. The influence of channel depth (10 and 20 mm) and volume flow rate on temperature rise has been investigated in this experimental investigation, and it has been discovered that the nanoparticle mass fraction (optimum mass fraction of the nanoparticles) relies on channel depth. Experimental results show that for optical depth of 10 mm, a temperature rise of 11.4 °C is obtained at the optimum mass fraction of 40 mg/L, and compared to this, at the optical depth of 20 mm, a temperature rise of 6.7 °C has been achieved at the optimum mass fraction of 10 mg/L. After evaluating the influence of volume flow rate (25–200 mL/hr), a maximum temperature rise of 11.2 °C was obtained at 25 mL/hr. In all cases, the temperature rise in the N-VAS (Nanoparticle-laden volumetric absorption-based system) is more significant than S-BAS (Surface-based absorption system), indicating that the presence of nanoparticles results in a higher heat transfer rate by absorbing more radiation from the heat source.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"27 ","pages":"Article 101158"},"PeriodicalIF":0.0,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143576851","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The influence of local resistance on the accuracy of the air velocity measurement with the air torque position damper","authors":"Siniša Bikić ,&nbsp;Nikola Vukadin ,&nbsp;Milivoj Radojčin ,&nbsp;Ivan Pavkov ,&nbsp;Rafat Al Afif","doi":"10.1016/j.ijft.2025.101155","DOIUrl":"10.1016/j.ijft.2025.101155","url":null,"abstract":"<div><div>Measuring airflow rate is essential in various industrial and engineering applications. The air torque position (ATP) damper is one device employed for this purpose, indirectly measuring air velocity by assessing the torque exerted by airflow on the blades and their position. This study aims to evaluate the impact of local resistance on the accuracy of airflow velocity measurements using the ATP damper. A laboratory ATP damper with a 250 mm x 250 mm square cross-section was utilized. Three damper designs with flat blades were tested: a single blade, two cross-guided blades, and two blades with one fixed horizontally. Two damper locations were considered: at the end of the ductwork and in the middle, with straight sections both upstream and downstream. A steel sheet reducing the duct's cross-sectional area by 50 % served as a local obstacle, positioned 0.5 m upstream and downstream of the damper. Two independent measurement series were conducted for each setup: one without the local resistance and one with it. Results indicated that local resistance upstream of the damper significantly affects airflow velocity measurement accuracy when the damper's angle of attack is ≤ 30°. This effect was consistent across all damper locations and designs tested. In order to determine the necessary length of straight duct sections without presence of local resistances upstream and downstream the damper, it is necessary in the future to continue research the impact of the presence of local resistance to the accuracy of air flow rate measurements using ATP dampers.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"27 ","pages":"Article 101155"},"PeriodicalIF":0.0,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biohydrogen production from algae: Technical possibilities and economic challenges","authors":"Malek Alkasrawi ,&nbsp;Marzieh Bagheri ,&nbsp;Nadeen Al-Smadi ,&nbsp;Mohamed Al Zarooni","doi":"10.1016/j.ijft.2025.101154","DOIUrl":"10.1016/j.ijft.2025.101154","url":null,"abstract":"<div><div>This study explores the potential of biohydrogen production from algae, investigating various technical pathways and addressing associated economic challenges. It reviews methods such as direct photolysis, indirect biophotolysis, gasification, and fermentation for extracting hydrogen from algae while also examining modeling techniques powered by IA. Thermodynamics of these methods are scrutinized for efficiency and viability, with a special emphasis on modeling for optimization. Algae cultivation, crucial for biohydrogen production, is thoroughly examined, detailing parameters like temperature and pH levels and bio-reactor designs. Additionally, the study conducts a Technical Economic Analysis (TEA) to evaluate the economic feasibility of these methodologies, providing insights for stakeholders and policymakers. The review also summarizes the AI approach to optimizing biohydrogen production.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"27 ","pages":"Article 101154"},"PeriodicalIF":0.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548006","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effects of HHO-enriched air on the combustion process and emission variation of simulated-biogas fueled spark ignition engine","authors":"Nguyen Phi Truong ,&nbsp;Khanh Nguyen Duc ,&nbsp;Trinh Xuan Phong ,&nbsp;Nguyen Tuan Nghia","doi":"10.1016/j.ijft.2025.101146","DOIUrl":"10.1016/j.ijft.2025.101146","url":null,"abstract":"<div><div>This paper investigates enhancing the operation characteristics and reducing pollutants of a simulated biogas (65 % CH₄ and 35 % CO₂) engine by the implementation of HHO gas. The simulation results showed that the appearance of HHO as an additive in charged air will shorten the ignition delay and combustion duration. HHO combustion lasts 40°, shorter than 44.5° without HHO. The RoHR peaks at 41.68 <em>J</em>/deg at 375 deg CA with HHO, compared to 34.52 <em>J</em>/deg without it. The maximum pressure rise is 1.90 bar/deg for gasoline, 0.97 bar/deg for simulated biogas, and 1.08 bar/deg for HHO-enriched biogas. The peak cylinder pressure was slightly raised from 42.12 bar to 45.73 bar with HHO aid. A system for supplying HHO to the intake manifold of the test engine was devised in a pilot model to conduct experiments. In comparison to the original gasoline engine, the average brake power of the biogas-fueled engine degraded by 39.1 % under full throttle conditions. The coefficient of variation of speed (COV_speed) under idling conditions increased from 0.31 % for gasoline to 1.58 % for the simulated biogas engine. However, as a small volume of HHO was presented in charge air, the biogas-fueled engine's performance and fuel economy improved by 7.86 % and 4.5 % at full-throttle conditions. Engine stability enhanced significantly as the COV_speed reduced from 1.58 % to 0.47 % with the HHO additive. The engine's exhaust emissions changed remarkably when operating with the HHO additive. Specifically, CO was reduced by 20.2 % on average at fully operated throttles and 6.5 % to 19.4 % at a constant speed of 4200 rpm; HC was moderately decreased 14.2 % on average at full throttle conditions and by 18.6 % on average at a constant speed of 4200 rpm; NO_x emissions increased marginally from 9.4 % to 33.4 % at full throttle conditions and an average increase of 35.5 % at a constant speed of 4200 rpm.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101146"},"PeriodicalIF":0.0,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143487410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Influence of ceiling fan induced mass flow rate to create uniform temperature distribution in a closed room: A CFD investigation","authors":"Sushant ,&nbsp;Ashok Kumar Yadav ,&nbsp;Ashish Dewangan ,&nbsp;Osama Khan ,&nbsp;Pankaj Kumar Sharma ,&nbsp;Niraj Kumar","doi":"10.1016/j.ijft.2025.101140","DOIUrl":"10.1016/j.ijft.2025.101140","url":null,"abstract":"<div><div>In the present work, Computational Fluid Dynamics (CFD) investigation of a newly developed fan blade of ceiling fan named “New Breeze” is carried out using CFD software ANSYS FLUENT. The moving reference frame technique and realizable k-ε model are used for numerical modeling. The analysis is carried out with blade having a lift angle of 6.5°, blade angle of 5.5°, twist angle of 4.5° and rotation speed of 320 rpm (revolution per minute). The profile of the blade is backward skewed type. The analysis for pressure-velocity coupling is done by SIMPLE algorithm. The k- ε equations which are used for spatial discretization of the momentum are second-order upwind, while first-order upwind are selected for the equation of energy and passive scalar. The aim is to determine the mass flow rate, velocity profile and total pressure of ceiling fan to measure the efficiency of the ceiling fan. Streamlines and contours are plotted to visualize the actual flow of air in a simulated test chamber. Finally, the result of simulation and that of experiment are compared. The mass flow rate of air at fan and closed chamber were 222.99 kg/s and 215 kg/s respectively.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101140"},"PeriodicalIF":0.0,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fluid flow and heat transfer investigation of microchannel heat sink with sidewall triangle ribs","authors":"Fadi Alnaimat ,&nbsp;Ahmad Rahhal ,&nbsp;Bobby Mathew ,&nbsp;Abdallah Berrouk","doi":"10.1016/j.ijft.2025.101141","DOIUrl":"10.1016/j.ijft.2025.101141","url":null,"abstract":"<div><div>This research evaluates heat transfer and pumping power associated with heat sinks having straight microchannels with triangular ribs on sidewalls using Ansys Workbench. The performance of the heat sinks is evaluated in terms of thermal resistance, pumping power, and a figure of merit (FOM). The heat sink with triangular ribs exhibits lower thermal resistance and higher pumping power than the straight MCHS. In addition, this study evaluates the influence of geometric parameters of the ribs on thermal resistance and pumping power. This study finds that increasing rib dimensions reduces thermal resistance by ∼ 57% while increasing pumping power; however, the FOM improves with reduction in dimensions of the ribs. Reducing the pitch of the fins reduces thermal resistance by ∼ 71% along with increase in the pumping power. Reducing microchannel spacing lowers thermal resistance by ∼68% without affecting pumping power, leading to improved FOM. The reduction in the dimensions of the microchannels improved thermal resistance by ∼ 52% while increasing pumping power; the FOM of MCHSs increased with an increase in channel dimensions.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101141"},"PeriodicalIF":0.0,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143437359","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Implications of waste cooking oil biodiesel on carbon steel alloy in automobiles: Corrosion degradation","authors":"Kenneth Kennedy Adama ,&nbsp;Kingsley Eghonghon Ukhurebor ,&nbsp;Uyiosa Osagie Aigbe ,&nbsp;Ismail Hossain","doi":"10.1016/j.ijft.2025.101143","DOIUrl":"10.1016/j.ijft.2025.101143","url":null,"abstract":"<div><div>The need to minimise metal degradation and dissolution in biodiesel (BD) fuels used in the transportation sector is nowadays becoming a challenging task that, if not properly attended to, can lead to human safety issues, environmental concerns, and vehicular failures in automobile systems. Metal degradation by BD fuel is a major issue of great concern to the scientific community, and this has resulted in intense research globally. Sustainable use of waste cooking oil (WCO) BD (WCOBD), which has a lower carbon footprint, and its implication on corrosion degradation in the transportation industry in terms of detailed applications of UV–Vis, FTIR, and SEM techniques to elucidate the corrosion behaviour of metallic components in the BD at various durations (0, 28, 42, and 56 days), temperature (25 °C), and atmospheric pressure (760 mmHg) are investigated in this study. The fuel properties of the produced WCOBD were within acceptable standard limits: viscosity of 4.785 mm²/s; density of 0.886 g/cm³; acid value of 0.120; flash point of 172.4 °C; fire point of 136 °C; cloud point of -4.2 °C; and pour point of -7.8 °C. The major fatty acid group responsible for the metal degradation was C18, with a high degree of unsaturation, having 90.63 % of the total constituent of the BD. UV–Vis analysis after the various immersion periods revealed two peaks at wavelengths of 928.3 and 1033.76 nm, which were formed during the esterification and transesterification reactions of the free fatty acid from the WCO and thus responsible for the metal degradation at the various immersion periods. FTIR spectra exhibited characteristics of double peaks around 2918 and 2842 cm^-1 wavelengths, with other peaks equally observed as being present in the BD. These peaks represented C<img>O, C<img>O, C<img>H, C<img>C, and (CH₂)_n functional groups as expected from free fatty acids in BD. SEM morphology revealed randomly distributed uneven structures, which were attributed to the formation of protective corrosion products and their physical adsorption on the metal surface. Thus, this study contributes to a deeper understanding of the corrosiveness of WCOBD to carbon steel, elucidates techniques to ascertain the degree and form of corrosion on the metal surface during storage and transportation of the BD in vehicular systems, and reveals the potential inherent in the use of un-inhibited WCOBD in real-world automotive applications.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101143"},"PeriodicalIF":0.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of solar energy generation potential in Western Bhutan – A case study of 12 kWp grid-tied rooftop solar photovoltaic system","authors":"Sonam Darjay ,&nbsp;Ephraim Bonah Agyekum","doi":"10.1016/j.ijft.2025.101142","DOIUrl":"10.1016/j.ijft.2025.101142","url":null,"abstract":"<div><div>In recent time, Bhutan as a small landlocked nation between China in the north and India in the south started to experience a gap in hydro electricity supply and demand. To address the growing electricity demand in the country, solar energy can be a diversification of Bhutan's renewable energy to address domestic energy security and global environmental concerns. In this paper, efforts have been made to assess the future energy potential from the rooftop solar photovoltaic (PV) systems in Thimphu City. For this study, we designed and simulated a 12 kWp grid-tied solar PV systems using PVSYST software. The result showed the annual solar energy generation, final energy yield and performance ratio (PR) of 19,336 kWh, 4.63 kWh/kWp and 84 % respectively. The estimated final energy yield and PR aligned with findings from countries like Saudi Arabia, India, and Pakistan, highlighting the strong solar energy potential in Thimphu. In addition, we conducted simple scenario analysis for energy generation potential when PV systems are installed on 90 %, 75 %, and 50 % of the available building rooftops in Thimphu City. The additional annual solar energy injected into the grid during lean hydropower generation periods was 61 GWh, 51 GWh, and 34 GWh for the three scenarios, respectively. Furthermore, the projected annual cost savings on electricity imports from additional energy generation from grid-tied rooftop solar PV systems was $3.23 million, $2.70 million, and $1.80 million across the three scenarios, using import price figure of 2023. Additionally, installing 12 kWp PV systems on 50 % of building rooftops in Thimphu City alone could result in environmental cost savings of $1.91 million during periods of low hydropower generation. The study is expected to benefit the government agencies, other institutions and individuals interested in solar energy generation using solar PV technology.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101142"},"PeriodicalIF":0.0,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143474467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Buoyancy effects on falkner-skan maxwellian nanofluid flow with bioconvection over a melting wedge","authors":"Rakesh Choudhary ,&nbsp;Amit Parmar ,&nbsp;Pramod Kumar ,&nbsp;Qasem Al-Mdallal","doi":"10.1016/j.ijft.2025.101136","DOIUrl":"10.1016/j.ijft.2025.101136","url":null,"abstract":"<div><div>This research investigates the intricate thermal dynamics of Maxwellian nanofluids interacting with a sloping, porous, and heat-conductive melting surface under the influence of magnetic fields. The thermal and hydrodynamic behavior of Maxwellian nanofluids plays a significant role in optimizing heat transfer applications in engineering and industrial processes. This study aims to examine the influence of buoyancy, bioconvection on the Falkner-Skan flow of Maxwellian nanofluids over a sloping, melting surface. The analysis assumes a porous and thermally conductive wedge surface subjected to a stable magnetic field and incorporates the effects of Brownian motion, thermophoresis, and gyrotactic microorganisms. To simplify the governing equations, similarity transformations are applied, converting the partial differential equations into a set of ordinary differential equations. The resulting equations are solved numerically using MATLAB's robust bvp4c solver, ensuring validation through comparison with existing literature. The study reveals that parameters such as the magnetic field strength, Deborah number, and melting surface characteristics significantly enhance flow behavior and boundary layer thickness, whereas parameters like Prandtl number and thermophoresis diminish temperature profiles. The findings underscore the critical interplay between magnetic and thermal parameters, providing insights for improving heat management in advanced technological systems. These results have practical implications for designing efficient thermal systems in industries ranging from chemical engineering to bio-nanomaterial production.</div></div>","PeriodicalId":36341,"journal":{"name":"International Journal of Thermofluids","volume":"26 ","pages":"Article 101136"},"PeriodicalIF":0.0,"publicationDate":"2025-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143465202","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}