Applied Thermal Engineering最新文献

{"title":"Internally stowed, radially deployed radiator panels for passive CubeSat thermal control","authors":"Josh R. Cannon ,&nbsp;Kyle N. Havey ,&nbsp;Noah S. Housley ,&nbsp;Rydge B. Mulford ,&nbsp;Brian D. Iverson","doi":"10.1016/j.applthermaleng.2025.126281","DOIUrl":"10.1016/j.applthermaleng.2025.126281","url":null,"abstract":"<div><div>CubeSats experience significant thermal loads due to solar irradiation and the dissipation from electrical components. The high heat dissipation per unit volume can lead to mission failure if not properly managed. Deployable radiators that are externally stowed and passively actuated in response to changes in CubeSat temperature have been explored as a viable solution. This work describes a radially deployed fin array that is stowed within the CubeSat body when the required heat dissipation is low and passively deploys when the required heat dissipation is high. Internal stowage improves thermal transport to the deployable fins and minimizes heat loss when thermal inputs are small. A test article was manufactured and tested in a cryogenically cooled vacuum chamber environment. Thermal simulation of the radiator system was developed using Thermal Desktop and calibrated using test data. A primary goal of this work was to determine the turndown ratio (largest cooling power / smallest cooling power) of the system which specifies the range of dynamic thermal control. For the experimental test conditions, a turndown ratio of 1.98 was achieved when considering heat loss from the entire CubeSat test article when the CubeSat body temperature is 325 K. However, the turndown ratio is much larger when considering only heat loss from the radiator panel thermal control system (8.35), as the heat loss from the panels is minimal when stowed. Results demonstrate the efficiency of a passive thermal control design in regulating CubeSat temperatures and the benefits of an internal stow design. This approach is shown to achieve a reduction in CubeSat body temperature of 60 °C with a phase lag of 10 min.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"270 ","pages":"Article 126281"},"PeriodicalIF":6.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686104","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":"Microscopic flow simulation of acid rock chemical reactions in multi-scale and multi-mineral porous media","authors":"Liang Zhou ,&nbsp;Hai Sun ,&nbsp;Cunqi Jia ,&nbsp;Gloire Imani ,&nbsp;Jun Yao","doi":"10.1016/j.applthermaleng.2025.126244","DOIUrl":"10.1016/j.applthermaleng.2025.126244","url":null,"abstract":"<div><div>The process of mineral dissolution in acid-rock reactions is of research significance for various fields such as oil and gas development and carbon dioxide storage. Natural rocks often contain different types of mineral components, and sub-resolution nanoscale pores can affect flow, mass transfer, and reactions. This study aims to further investigate the effects of mineral component distribution and sub-resolution pores on dissolution under different acid injection conditions. By utilizing the Darcy-Brinkman-Stokes equations to couple multi-scale flow, we establish fluid mass conservation equations that consider the mass exchange between acid solutions and mineral components, as well as mass conservation equations for the mineral components. The results indicate that the presence of horizontally layered dolomite can lead to localized uniform dissolution under conditions of strong convective ability. Under high diffusion coefficients, the combination of dolomite with insoluble minerals is beneficial for breaking the stable dissolution front, and oscillations in curvature can enhance the breakthrough capacity of the acid. In the wormhole model, larger nanoscale pore sizes facilitate the breakthrough of the acid solution. However, under high diffusion coefficients, the differences in permeability growth and breakthrough capacity of the acid solution among different cores are significantly reduced. Quantitative comparisons further demonstrate that the distribution of minerals and pore sizes has a non-negligible impact on dissolution, with the differences in pore permeability growth for different mineral components and nanoscale pore distributions reaching up to 5.02 times and 10.2 times, respectively.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126244"},"PeriodicalIF":6.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681050","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":"Effect of intake oxygen concentration and ammonia energy ratio on combustion and emission characteristics of ammonia/diesel RCCI engine under low load","authors":"Sicheng Lai ,&nbsp;Wenjun Zhong ,&nbsp;Yunlong Huang ,&nbsp;Shiman Zou ,&nbsp;Xu Liu ,&nbsp;Kang Yang ,&nbsp;Zhixia He ,&nbsp;Qian Wang","doi":"10.1016/j.applthermaleng.2025.126275","DOIUrl":"10.1016/j.applthermaleng.2025.126275","url":null,"abstract":"<div><div>The ammonia/diesel RCCI engine is one of the most promising methods for utilizing ammonia in combustion. Under high AER (Ammonia energy ratio), the ammonia combustion resistance characteristic, unburnt ammonia, and the N₂O emissions hinder the use of ammonia/diesel RCCI engines and violate the original intention of low-carbon emissions. This research investigate the effect of intake oxygen enrichment strategy on the ammonia/diesel RCCI engine through CFD simulations. The results indicate that as the IOC (intake oxygen concentration) increases, both the pressure and heat release rate in the cylinder increase, while the ignition delay time and combustion duration shorten. Under 27 % IOC, the ITE of AER80 will increase from 26 % to 27.9 %. Due to the enhancement of combustion characteristics in the cylinder, the emissions of unburnt ammonia of AER80 will significantly decrease from 13.65 g/KWh to 0.07 g/KWh and the GHG emission will also decrease 20 %, but NO_X emissions will deteriorate due to the high temperature and abundant oxygen environment. Therefore, AER50 is not suitable for intake oxygen enrichment strategy, AER60 is suitable at 23 % IOC, and AER70, and 80 are more suitable at 25 % IOC. Chemical kinetic analysis shows that increasing IOC intensifies the rate of the <span><math><mrow><mover><mrow><mi>O</mi><mi>H</mi></mrow><mo>̇</mo></mover></mrow></math></span> production, primarily through the reactions, 2 <span><math><mrow><mover><mrow><mi>O</mi><mi>H</mi></mrow><mo>̇</mo></mover></mrow></math></span>(+M)=H₂O₂(+M) and <span><math><mrow><mover><mrow><mi>N</mi><msub><mi>H</mi><mn>2</mn></msub></mrow><mo>̇</mo></mover></mrow></math></span> + HO₂=H₂NO+<span><math><mrow><mover><mrow><mi>O</mi><mi>H</mi></mrow><mo>̇</mo></mover></mrow></math></span>, which can accelerate ignition process. Additionally, it can increase the proportion of downstream reaction pathways for N₂O, N₂O(+M)=N₂+<span><math><mrow><mover><mi>O</mi><mo>̇</mo></mover></mrow></math></span>(+M) and N₂O+<span><math><mrow><mover><mi>H</mi><mo>̇</mo></mover></mrow></math></span>=N₂+<span><math><mrow><mover><mrow><mi>O</mi><mi>H</mi></mrow><mo>̇</mo></mover></mrow></math></span>, accelerating the chain termination reaction, which results in the increase in N₂O rate of consumption and the reduction of N₂O emissions.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126275"},"PeriodicalIF":6.1,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143681038","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 study on the heat transfer performance of finned-tube heat exchangers in latent thermal energy storages: Effects of PCM types and operating conditions","authors":"Matteo Dongellini ,&nbsp;Giulia Martino ,&nbsp;Claudia Naldi ,&nbsp;Sylvie Lorente ,&nbsp;Gian Luca Morini","doi":"10.1016/j.applthermaleng.2025.126273","DOIUrl":"10.1016/j.applthermaleng.2025.126273","url":null,"abstract":"<div><div>In this paper, the thermal performance of a new Latent Thermal Energy Storage (LTES) system made of a finned-tube heat exchanger dipped in a paraffinic Phase Change Material (PCM) is studied experimentally and compared to that of a Sensible Thermal Energy Storage (STES), obtained by immersing the same heat exchanger in water. In order to present general results, the influence of the heat exchanger geometry, PCM type and operating conditions on the LTES heat storing capacity and heat transfer rate between PCM and Heat Transfer Fluid (HTF) was assessed. In particular, 1-row and 2-row finned-tube heat exchangers were immersed in two commercially available paraffinic PCMs, characterised by different melting ranges and latent heat capacities. The HTF mass flow rate and HTF inlet temperature were varied during test cycles, and the charging and discharging processes of the TES systems were investigated. The experimental results show that the heat-storing capacity of the LTES can be increased by up to 200 % with respect to that of an equivalent STES during both processes. Even though high values of thermal power during the LTES charging/discharging cycles can be achieved, with a peak of 1900 W, the system thermal performance is reduced compared to that of a STES operated under the same conditions. For HTF flows with Reynolds numbers higher than 2000, the average heat transfer rate between HTF and PCM decreases by up to 40 % with respect to an equivalent sensible storage. However, selecting the optimal system configuration and proper operating conditions, such as the use of a 1-row heat exchanger and low values of the HTF mass flow rate, allows for limiting that penalisation to 5–10 %. The results of the present study emphasise how the LTES configuration, PCM type, and operating conditions strongly influence the system thermal performance. The experimental data can also be used as a benchmark to optimise the design of latent thermal energy storages and validate numerical models.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"271 ","pages":"Article 126273"},"PeriodicalIF":6.1,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143680972","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":"An analytical model for the short-term response of energy piles considering temperature variation effect at the pile-soil interface","authors":"Qingkai Zhang ,&nbsp;Xiangyun Zhou ,&nbsp;De’an Sun ,&nbsp;You Gao ,&nbsp;Minjie Wen ,&nbsp;Shixiang Hu ,&nbsp;Weiding Zhuo","doi":"10.1016/j.applthermaleng.2025.126278","DOIUrl":"10.1016/j.applthermaleng.2025.126278","url":null,"abstract":"<div><div>Energy piles are an innovative type of ground-source heat pump system that provide heating or cooling for buildings by exchanging heat between the pile foundation and surrounding soil. Heat transfer at the energy pile-soil interface plays a crucial role in determining the temperature distribution in the surrounding soil and the heat exchange efficiency of energy piles. Current models typically rely on simplifying assumptions such as a constant power heat source, continuous interface temperatures, and constant temperature boundaries, which can lead to inaccuracies in predicting the soil temperature response. To address this issue, a novel layered heat transfer model for energy piles was proposed in this study, which incorporates the actual effects of soil interfacial thermal resistance, pile-soil heat transfer, and convective heat exchange between the ground surface and air. This model offers a more accurate representation of the thermal response of the energy pile system. Semi-analytical solutions for the short-term response of energy pile were derived using the finite Hankel and Laplace transforms, and the Crump method was employed to numerically invert the Laplace-domain solutions to obtain the corresponding time-domain solutions. The model’s accuracy and validity were verified by comparisons with the existing analytical solutions, numerical simulations, and experimental data. The findings of this study indicate that, compared to the traditional constant power source model, the pile-soil heat transfer model used in this work more effectively simulates the actual soil temperature distribution, particularly improving the prediction accuracy by approximately 45 % to 95 % in the short-term response phase. The results of parametric study indicate that for every increase of 1 W/(K·m²) in the pile-soil heat transfer coefficient, the soil temperature increased by approximately 0.1 to 0.5 °C, corresponding temperature growth rate decreases from 92.7 % to 1.8 %. For each 200 W increase in heat pump power, the soil temperature rose by about 0.5 °C, with a percentage increase of 2 % to 4 %. Moreover, an increase in the air convective heat transfer coefficient led to higher shallow soil temperatures. Specifically, for every 2 W/(K·m²) increase in the convective heat transfer coefficient, the soil temperature increased by approximately 0.08 to 2.48 °C, with a percentage rise of 2.3 % to 22.9 %.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"270 ","pages":"Article 126278"},"PeriodicalIF":6.1,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685706","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":"Designing reinforcement learning algorithms for building HVAC control: From experimental observation to simulation comparisons","authors":"Fangzhou Guo ,&nbsp;Sang woo Ham ,&nbsp;Donghun Kim ,&nbsp;Sun Ho Kim ,&nbsp;Hyeun Jun Moon","doi":"10.1016/j.applthermaleng.2025.126106","DOIUrl":"10.1016/j.applthermaleng.2025.126106","url":null,"abstract":"<div><div>Advanced supervisory-level control with reinforcement learning (RL) is regarded as a promising solution for HVAC systems to minimize energy consumption while maintaining thermal comfort and indoor air quality. However, most RL applications were conducted in the simulation environment rather than real-world HVAC systems. This paper developed a value-based RL controller termed Deep Q-Network (DQN) for a typical central HVAC system and evaluated its performance in a building test facility. By comparing DQN with a rule-based controller, the study not only demonstrated the cases where DQN could properly maintain indoor comfort but also discussed possible reasons why DQN failed in some other situations. Recognizing the limitations of value-based RL algorithms from the experimental tests, a simulation study was conducted to compare DQN with an alternative RL approach, an actor–critic algorithm termed Deep Deterministic Policy Gradient (DDPG). In scenarios with a relatively large action space, DDPG outperformed DQN by requiring fewer computational resources and achieving better thermal comfort, lower energy consumption, and more stable control actions. The findings suggest that the ability of DDPG to handle continuous control variables more effectively allows for faster convergence in training and more precise control in practice, which enhances the overall efficiency and reliability of the HVAC system.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"270 ","pages":"Article 126106"},"PeriodicalIF":6.1,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685756","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":"An experimental investigation on phase-change transpiration cooling with SiC porous ceramic","authors":"P.F. Zhu,&nbsp;X.K. Song,&nbsp;Q.L. Song,&nbsp;Y.H. Cao,&nbsp;W.Q. Li","doi":"10.1016/j.applthermaleng.2025.126274","DOIUrl":"10.1016/j.applthermaleng.2025.126274","url":null,"abstract":"<div><div>Transpiration cooling with phase change is an effective cooling method for protecting the leading edge of hypersonic vehicles and scramjet engines from thermal failure. Previous research has revealed the transpiration cooling performance with porous metallic materials or ceramic-based composites. However, limited research has explored how non-uniformity of heat fluxes of incoming flow affect phase-change transpiration cooling performance in sintered SiC particles. Herein, we experimentally investigate the transpiration cooling performance of sintered SiC porous plate subjected to high-temperature flame with non-uniform heat fluxes along the radial direction, and compare that to porous sintered metal particles. Results show that at 17 % coolant injection rate, overheating phenomenon is first observed at the center of stainless-steel porous plate due to the highest aerodynamic heat. Comparatively, the highest temperature at the center of the SiC porous plate (<em>ε</em> = 38.4 %) is capable of stabilizing at around 103 ℃ due to its higher thermal conductivity. Moreover, when oxygen-fuel ratio is lower (O/F = 0.86) and the coolant mass flow rate <span><math><mrow><mspace></mspace><msub><mover><mi>m</mi><mo>̇</mo></mover><mi>c</mi></msub><mspace></mspace></mrow></math></span> is 4 mL/min, the SiC porous plate exhibits higher top-surface temperatures along with greater radial and longitudinal temperature gradients (7.9 ℃ and 78.1 ℃). Furthermore, when <span><math><mrow><mspace></mspace><msub><mover><mi>m</mi><mo>̇</mo></mover><mi>c</mi></msub><mspace></mspace></mrow></math></span> is 3 mL/min, the top-surface center temperature oscillates with an average period of around 100 s and an amplitude of 861.3 ℃. Additionally, when the porosity decreases from 43.3 % to 38.4 %, the delayed oscillation onset, shortened periods, and increased temperature amplitude are obtained, at the cost of increase of inlet pressure, with a maximum pressure reaching up to 75.4 kPa.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"270 ","pages":"Article 126274"},"PeriodicalIF":6.1,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686223","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":"Hybrid thermal management of solar photovoltaics using gas and liquid channel cooling with numerical and experimental analysis","authors":"Kexiang Zhou ,&nbsp;Xincheng Liu ,&nbsp;Guoqiang Xu ,&nbsp;Hui Wu ,&nbsp;Qingtao Pang ,&nbsp;Qinlong Ren","doi":"10.1016/j.applthermaleng.2025.126261","DOIUrl":"10.1016/j.applthermaleng.2025.126261","url":null,"abstract":"<div><div>With the rapid development of social productivity, the human demand of energy consumption is significantly increased. Solar photovoltaic has become an essential technology for power generation instead of fossil fuel during the past decade owing to the abundant existence of global solar resource. Unfortunately, the photovoltaic panel suffers from an inevitable issue of 0.4 %-0.5 % reduction on solar energy to electricity conversion efficiency when its temperature is raised up by 1 ℃. In addition, when the photoelectric conversion efficiency of solar photovoltaics drops down, an increased amount of waste heat is generated, further deteriorating the corresponding thermal issue especially during summer season. The traditional thermal management approach of solar photovoltaic applying individual gas or liquid as heat transfer fluid has the following obvious shortcomings: low thermal conductivity and specific heat of gas with limited heat absorption; high viscosity of liquid with high pressure drop and pump power. Facing these challenges, the current work presents a hybrid gas and liquid thermal management technology of solar photovoltaic with designed fluid flow channels. Consequently, the back panel of solar photovoltaic can be cooled down by liquid cooling flow, while its front surface temperature is simultaneously dropped down through gas blowing flow cooling process. When a gas blowing flow of 4.5 m/s and liquid cooling flow of 0.08 m/s are applied at 20 ℃, the average temperature of solar photovoltaic under a solar irradiation of 1000 W/m² dramatically decreases from 66.5 ℃ to 38.8 ℃ by 41.65 %. Meanwhile, the corresponding output power of solar photovoltaics is improved from 0.658 W to 0.942 W by 43.16 %. Specifically, the average temperature of solar photovoltaic using hybrid gas and liquid channel cooling is decreased by 9.7 ℃ and 5.7 ℃ in comparison to applying individual gas channel cooling or liquid channel cooling, respectively. The current work paves a promising approach for solar photovoltaic thermal management, which can significantly ameliorate its power generation performance in practical applications.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"270 ","pages":"Article 126261"},"PeriodicalIF":6.1,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686222","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":"PMV modification model for low-pressure and non-uniform indoor environment","authors":"Linfeng Liang ,&nbsp;Shaojie Guo ,&nbsp;Xin Su ,&nbsp;Yukun Wang ,&nbsp;Zhengwei Long","doi":"10.1016/j.applthermaleng.2025.126266","DOIUrl":"10.1016/j.applthermaleng.2025.126266","url":null,"abstract":"<div><div>The Predicted Mean Vote (PMV) model, widely used in indoor thermal comfort assessment, performs poorly in low-pressure and non-uniform thermal environments. Existing modified PMV models are limited by their reliance on uniform conditions and standard atmospheric parameters, while traditional models for evaluating thermal sensation in non-uniform environments involve complex calculations. This study innovatively integrates the Local Thermal Sensation (LTS) assessment model with the pressure-corrected PMV_C model to propose a novel PMV correction method. This approach effectively addresses the challenge of coupling low pressure with environmental non-uniformity, enabling rapid thermal comfort prediction based solely on input environmental parameters. The proposed method was applied to a typical low-pressure, non-uniform thermal environment scenario—the aircraft cockpit. Results indicate that the most thermally sensitive regions for cockpit occupants are the head, hands, feet, and calves. Notably, solar radiation significantly influences local thermal variations, with thermal sensation differences of up to 0.62 units observed between pilots’ heads. Based on these sensitive regions, the study develops localized PMV_L calculation formulas for 16 body parts and determines an overall thermal comfort evaluation formula: O-PMV_L = 0.7829PMV_C − 0.3802, incorporating the weight of each body part’s contribution to overall thermal comfort. The findings significantly expand the applicability of the PMV model, enabling its use in aerospace and extreme environments. Additionally, the study provides key indicators and guidance for optimizing thermal environment design, facilitating advancements in thermal comfort design for various industries operating in specialized environments.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"270 ","pages":"Article 126266"},"PeriodicalIF":6.1,"publicationDate":"2025-03-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143686221","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":"Impact of adjacent spray–plume interaction on far-field droplet characteristics in rotary slinger atomizers","authors":"Arshdeep Singh,&nbsp;Srikrishna Sahu","doi":"10.1016/j.applthermaleng.2025.126196","DOIUrl":"10.1016/j.applthermaleng.2025.126196","url":null,"abstract":"<div><div>Slingers are a type of rotary atomizer in which liquid is injected through multiple orifices located around the periphery of a rotating disc. Despite previous studies on slingers, the interaction between spray–plumes from adjacent orifices remains poorly understood. This study aims to bridge that gap by investigating how these interactions influence spray characteristics through droplet collisions. Understanding the conditions that promote such interactions is crucial for optimizing atomization efficiency and performance. Our focus is to elucidate the underlying physics governing plume interaction. The experiments were performed in a slinger test facility utilizing three slinger discs with different numbers of orifices, <span><math><mover><mrow><mi>n</mi></mrow><mrow><mo>˜</mo></mrow></mover></math></span> (= 18, 4, 2) such that the number of adjacent orifices is higher for greater <span><math><mover><mrow><mi>n</mi></mrow><mrow><mo>˜</mo></mrow></mover></math></span>. The visualization of primary liquid breakup and droplet size measurement results reveal that the liquid atomization is dictated by the liquid flow rate per orifice (<span><math><msub><mrow><mover><mrow><mi>q</mi></mrow><mrow><mo>̇</mo></mrow></mover></mrow><mrow><mi>l</mi></mrow></msub></math></span>) rather than inlet flow rate (<span><math><msub><mrow><mover><mrow><mi>Q</mi></mrow><mrow><mo>̇</mo></mrow></mover></mrow><mrow><mi>l</mi></mrow></msub></math></span>). For the same <span><math><msub><mrow><mover><mrow><mi>q</mi></mrow><mrow><mo>̇</mo></mrow></mover></mrow><mrow><mi>l</mi></mrow></msub></math></span> and rotational speed in all three slinger discs, the liquid breakup mode is similar, yet the characteristic droplet size is higher for the disc with a greater <span><math><mover><mrow><mi>n</mi></mrow><mrow><mo>˜</mo></mrow></mover></math></span> (from 2- to 18-orifice disc). This is attributed to spray-plume interaction that promotes droplet collision and coalescence. Various statistical parameters were calculated, including radial distribution function (<span><math><mi>RDF</mi></math></span>), droplet relative velocity (<span><math><msub><mrow><mi>V</mi></mrow><mrow><mi>r</mi><mi>e</mi><mi>l</mi></mrow></msub></math></span>) and collision Weber number (<span><math><msub><mrow><mi>We</mi></mrow><mrow><mi>c</mi><mi>o</mi><mi>l</mi></mrow></msub></math></span>), which provide reasonable evidence of droplet collision in the spray. The current study offers valuable insight into the design and development of the rotary slinger atomizers.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"270 ","pages":"Article 126196"},"PeriodicalIF":6.1,"publicationDate":"2025-03-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143685692","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}