Applied Thermal Engineering最新文献

{"title":"Feasibility and pipe length prediction Method of the soil direct cooling system for small data centers","authors":"Hongzhi Zhang ,&nbsp;Zongwei Han ,&nbsp;Gemeng Cao ,&nbsp;Huai Wang ,&nbsp;Yixin Wu ,&nbsp;Haoxue Liu ,&nbsp;Qinghai Wang ,&nbsp;Lingyan Yang","doi":"10.1016/j.applthermaleng.2025.125685","DOIUrl":"10.1016/j.applthermaleng.2025.125685","url":null,"abstract":"<div><div>Small data centers are numerous and their cooling systems are inefficient. Air/Water-based free cooling technology can enhance cooling system efficiency, but some application issues limit its promotion. Targeting the feature of rich surrounding soil resources, this paper proposes the soil direct cooling system with strong adaptability and high energy-saving potential for small data centers. To study this cooling system feasibility under the continuous heat release impact of small data centers and the influence of key parameters on the system performance, an accurate three-dimensional simulation model for heat exchange between ground heat exchangers and soil is established. Results indicate that when the length of ground heat exchangers is designed reasonably, the soil direct cooling system can ensure the long-term stable operation of small data centers, and the coefficient of performance of system can reach up to 25.78 ∼ 37.85. The pipe length considering soil internal moisture transfer increases by about 5.41 % compared with the pure heat conduction condition. For every 0.75 W/(m·K) increase in soil thermal conductivity, 200 J/(kg·K) increase in soil specific heat capacity, 0.5 m increase in borehole spacing and 0.5 °C increase in initial soil temperature, the pipe length decreases by 15.93 %∼19.23 %, 11.54 %∼13.59 %, 14.55 %∼17.02 % and increases by 13.95 %∼17.54 %, the coefficient of performance of system increases by 2.30 ∼ 2.71, 1.54 ∼ 1.93, 2.08 ∼ 2.45 and decreases by 1.46 ∼ 1.99. A multiple regression analysis on the heat exchange rate per unit buried depth of ground heat exchangers is conducted. According to the regression result and cooling load of data centers, the pipe length can be predicted, which can provide guidance for the practical engineering application of this system.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"266 ","pages":"Article 125685"},"PeriodicalIF":6.1,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168988","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":"ANN based solar thermal energy forecasting model and its heating energy saving effect through thermal storage","authors":"Ho Seong Jeon ,&nbsp;Sang Hun Yeon ,&nbsp;Jun Kyu Park ,&nbsp;Min Hwi Kim ,&nbsp;Yeobeom Yoon ,&nbsp;Chul Ho Kim ,&nbsp;Kwang Ho Lee","doi":"10.1016/j.applthermaleng.2025.125740","DOIUrl":"10.1016/j.applthermaleng.2025.125740","url":null,"abstract":"<div><div>Among various types of renewable energy sources, solar thermal energy can be economically utilized for space heating and service hot water. However, its performance is significantly influenced by the orientation and location of panels, as well as weather conditions. Therefore, accurate prediction of solar thermal systems is essential to ensure the reliability and stability of the technology. This study aims to predict solar thermal energy production using Artificial Neural Networks (ANN) and to apply the technology integrated with thermal storage for energy savings. A predictive model was developed using field data collected from solar thermal collectors in the community complex from August 1, 2019, to July 31, 2020. The performance of the predictive model was evaluated using Cv(RMSE), NMBE, and R² indexes as recommended by ASHRAE Guideline 14-2014. The accuracy of the hourly data predictive model showed ANN prediction results of Cv(RMSE) = 11.7 %, NMBE = −1.21 %, R² = 0.93. To evaluate the heating energy saving by applying the ANN predictive model to the target buildings, five cases were selected. The Base_case represents the space heating and service hot water load of the building itself. Case_1 applies the predicted solar thermal energy production to the Base_case, and Case_2 applies the measured solar thermal energy production. Case_3 applies a storage tank to Case_1, and Case_4 applies a storage tank to Case_2. It turned out that Case_1 and Case_2 showed about a 14 % energy saving rate compared to Base_case. Case_3 and Case_4 showed about a 43 % saving rate compared to Base_case, and about 34 % compared to Case_1 and Case_2.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"267 ","pages":"Article 125740"},"PeriodicalIF":6.1,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143171997","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":"Thermal-economic analysis and optimization of a novel segmented energy storage Carnot battery","authors":"Yuchen Li,&nbsp;Peng Hu,&nbsp;Hui Ni","doi":"10.1016/j.applthermaleng.2025.125713","DOIUrl":"10.1016/j.applthermaleng.2025.125713","url":null,"abstract":"<div><div>As a new type of energy storage technology using thermal energy, the Carnot battery (CB) is one of the most promising large-scale energy storage technologies due to its unlimited geographical conditions, simple structure, and high energy storage density. Previous research has mainly focused on the individual analysis of the working fluid or the conventional CB system, and the comprehensive thermal economy analysis of the system is lacking. In this work, a novel CB system with segmented energy storage using zeotropic working fluids is proposed, and the effects of the working fluid mass fraction, waste heat temperature and heat storage temperature on system performance are investigated. The multi-objective optimization problem of maximizing the power recovery efficiency and minimizing the initial investment cost is studied, and systematic Pareto-optimal solutions are obtained. The novelty of this work is the use of segmented condensation at the saturated liquid phase point of the working fluids. The temperature matching of the heat exchanger is modified by adjusting the mass flow rate of the heat storage water to reduce heat transfer exergy losses and improve the system performance. Compared with the conventional CB system, the novel system improves the power recovery efficiency by 3.31–24.07 % and the economic index, the levelized cost of storage (LCOS) by 2.87–17.25 %. The zeotropic working fluid R245fa/pentane (mass fraction of 40/60) shows the best thermal performance, with a power recovery efficiency of 74.13 %, which is 23.51 % greater than that of pure R245fa and 18.97 % greater than that of pure pentane. The zeotropic working fluid R245fa/pentane (40/60) achieves the minimum LCOS of 0.213 $/kWh at a waste heat temperature of 80.0 ℃ and a storage temperature of 94.2 ℃, which is 8.06 % higher than the LCOS of 0.232 $/kWh for pure pentane, and 10.83 % higher than the LCOS of 0.239 $/kWh for pure R245fa. The selection of a zeotropic working fluid with an appropriate temperature glide can effectively improve the thermal and economic performance of the system.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"266 ","pages":"Article 125713"},"PeriodicalIF":6.1,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143170039","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":"A Multilevel-Multiphysics modeling and simulation approach for multichip electronics","authors":"Xiaoming Zhou ,&nbsp;Yongchao Liu ,&nbsp;Manthar Ali ,&nbsp;Min He","doi":"10.1016/j.applthermaleng.2025.125738","DOIUrl":"10.1016/j.applthermaleng.2025.125738","url":null,"abstract":"<div><div>Thermo-mechanical and thermo-electro modeling and simulation (M&amp;S) are commonly demanded in the development of electronic systems. However, such work is often difficult and time consuming because of the scale difference among multilevel domains, especially for the multichip electronics where there are a lot of repeating details. Usually, simplified models, which suppress multiscale features, have to be used to make a compromise. In this work, a multilevel-multiphysics M&amp;S approach is presented to address the need for efficient multiphysics modeling of multichip electronics as well as better characterization the interaction among multilevel domains. An open-source platform, Multiphysics Object Oriented Simulation Environment (MOOSE), is used to as an enable tool because of its multiphysics M&amp;S ability as well as the flexible data transferring functions. Prior to simulation, a multichip system is divided into different levels of domains, which are meshed separately to avoid multiscale feature in each model. Then the inherent thermal, electrical and mechanical behaviors of each level of domains, as well as the interactions with the other levels of domains, are modeled and described with a separate MOOSE app. The prepared apps provide a library of pluggable blocks in the following work. To perform simulation for a specific system, a set of apps are loaded on demand. First, the top-level app, i.e., the main app, is loaded and calls a series of sub apps at given positions and simultaneously initiates two-way interface data transferring between them. Further, each sub app may call its sub-sub apps. By such level-by-level calling, the multilevel models are integrated. A two-way data exchange strategy is proposed and the fixed-point iteration algorithms are used to guarantee data continuity across the interfaces. Notably, the repeating details (e.g., the same type of chips/modules on a board) can be modeled easily by calling the same sub app at multiple positions. Moreover, the pluggable architecture makes the multilevel models be readily reconfigurable, and thus provides valuable flexibility for co-design and development iteration. A prototype with a board and 16 thermal testing chips has been simulated and tested for verification and validation of the approach, and the results demonstrated favorable accuracy and efficiency. Further, the approach was applied to a practical phased array antenna, which contains 63 transmit/receive modules and 189 power amplifiers. Complete and detailed thermomechanical results were successfully obtained with good data consistency from the whole antenna to each chip, suggesting the presented approach enables effective multilevel-multiphysics M&amp;S for such complicated multichip electronics.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"266 ","pages":"Article 125738"},"PeriodicalIF":6.1,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168990","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 acoustic-driven high-power rotary triboelectric generator","authors":"Hao Chen ,&nbsp;Yupeng Yang ,&nbsp;Junxiang Wang ,&nbsp;Yurui Shang ,&nbsp;Wei Tang ,&nbsp;Guoyao Yu ,&nbsp;Rui Yang ,&nbsp;Ercang Luo","doi":"10.1016/j.applthermaleng.2025.125752","DOIUrl":"10.1016/j.applthermaleng.2025.125752","url":null,"abstract":"<div><div>To develop a high-power electrical source, we propose a non-contact fiber-reinforced rotary triboelectric generator (NFTEG), based on which an acoustic-driven NFTEG is also developed. Systematic experiments are conducted to investigate the characteristics of NFTEG. An open-circuit voltage of 3500 V and a short-circuit current of 0.38 mA are achieved, and the initial output current is sustained even after 500,000 cycles of continuous operation. Further, the performance of NFTEG reveals significant sensitivity to mean pressure and gas species variations, with the optimal mean pressure depending on gas species. A maximal output voltage of 3520 V is obtained in CO₂, revealing CO₂ as a proper gas for NFTEG. Importantly, in the experiments with the acoustic-driven NFTEG, a time-averaged electric power output as high as 1.46 W is obtained with 0.5-MPa CO₂ gas and an acoustic frequency of 35 Hz. These results shed light on the feasibility of the acoustic-driven NFTEG as a high-power electrical source, with the advantage of high reliability.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"267 ","pages":"Article 125752"},"PeriodicalIF":6.1,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173155","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":"Bio-inspired volute disk for performance enhancement of metal hydride reactor coupled with nanoparticles enhanced phase change material","authors":"Di Wang ,&nbsp;Jiayun Liang ,&nbsp;Qiang Hu ,&nbsp;Jia Lu ,&nbsp;Sinan Guan ,&nbsp;Yuqi Wang ,&nbsp;Zhen Wu","doi":"10.1016/j.applthermaleng.2025.125693","DOIUrl":"10.1016/j.applthermaleng.2025.125693","url":null,"abstract":"<div><div>Metal hydride is widely recognized as the efficiently method to storage H₂ due to its saving energy, safety, low cost and high H₂ storage capacity. However, heat transfer has always been the key limiting factor in the application of metal hydride H₂ storage reactors. A novel bionic volute disk reactor was proposed to effectively enhance heat transfer performance and accordingly accelerate H₂ storage efficiency. Additionally, the excellent stable scalability characteristics of volute structure can satisfy the diverse requirements for H₂ storage capacity in various application scenarios. Meanwhile, phase change material and nanoparticles were introduced to considerably improve heat transfer and H₂ storage efficiency at minimizing heat management during application. The reaction performances were investigated and optimized using 3D models, and the results illustrated that bionic volute disk reactor can improve hydrogenation efficiency by 40 % and dehydrogenation efficiency by 27 % compared to traditional planar spiral disk reactor. Meanwhile, the structural parameter investigations indicated that bionic volute disk reactor could achieve optimal performance with spiral turns of 3.5, tube diameter of 8 mm and spiral end radius of 40 mm. Moreover, the quality sensitivity analysis revealed the exceptionally stable scalability of bionic volute disk reactor can be achieved by adjusting tube length and layer count without compromising reaction performance. Furthermore, adding 20 % nanoparticles can increase the heat transfer rate by 19 % during absorption and 21 % during desorption, demonstrating an improvement in heat transfer characteristics and an enhancement of rapid response performance.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"266 ","pages":"Article 125693"},"PeriodicalIF":6.1,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance evaluation of MEMS heat sinks having straight microchannels integrating rectangular sidewall cavities in in-line pattern","authors":"Nedal Omar El-Saeh ,&nbsp;Fadi Alnaimat ,&nbsp;Bee Teng Chew ,&nbsp;Bobby Mathew","doi":"10.1016/j.applthermaleng.2025.125696","DOIUrl":"10.1016/j.applthermaleng.2025.125696","url":null,"abstract":"<div><div>This work details a silicon-based MEMS heat sink having straight microchannels integrating rectangular sidewall cavities in in-line pattern and employing water for thermal management of microelectronic chips. Simulation-based studies are done for Reynolds number (<em>Re</em>) between 100 and 750 and the model is validated. The thermal resistance (<em>R_th,total</em>) and pumping power (<em>PP_f</em>), of the proposed MEMS heat sink, are lower than that of the conventional MEMS heat sink. At the largest <em>Re</em>, the <em>R_th,total</em> of the proposed MEMS heat sink is only ∼78 % of the <em>R_th,total</em> of the conventional MEMS heat sink and <em>PP_f</em> of the former is only ∼91 % of the latter. Moreover, the Nusselt number (<em>Nu</em>) and Poiseuille number (<em>Po</em>) of the straight microchannel integrating rectangular sidewall cavities is higher and lower than that of the straight microchannel, respectively. With the increase in <em>Re</em>, the <em>Nu</em> of the proposed MEMS heat sink in comparison with that of a conventional MEMS heat sink varied from ∼103 % to ∼147 % while the <em>Po</em> of the former in comparison with the latter varied from ∼81 % to ∼91 %. There exists a threshold for the length of the sidewall cavities below which the performance of the proposed MEMS heat sink is not influenced by the same. Above this threshold, increase in length decreases, for a specific <em>Re</em>, both <em>R_th,total</em> and <em>PP_c</em> as well as increases and decreases the <em>Nu</em> and <em>Po</em>, respectively. Increase in <em>Re</em> leads to reduction of <em>R_th,total</em> and increase of <em>Nu</em> with decrease in the width of the sidewall cavities; both <em>PP_f</em> and <em>Po</em> increase with increase in <em>Re</em> though the influence of width of sidewall cavities on them is negligible. The increase in the number of sidewall cavities decreases <em>R_th,total</em> and <em>PP_f</em> while increasing and decreasing the <em>Nu</em> and <em>Po</em>, respectively. The increase in hydraulic diameter decreases both <em>R_th,total</em> and <em>PP_f</em> while increasing both <em>Nu</em> and <em>Po</em>.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"266 ","pages":"Article 125696"},"PeriodicalIF":6.1,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168642","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Performance assessment of a novel localized cooling system for battery thermal management at high ambient conditions","authors":"Hemanth Dileep,&nbsp;Praveen Dhanalakota,&nbsp;Pallab Sinha Mahapatra,&nbsp;Arvind Pattamatta","doi":"10.1016/j.applthermaleng.2025.125756","DOIUrl":"10.1016/j.applthermaleng.2025.125756","url":null,"abstract":"<div><div>Battery thermal management systems are crucial for electric vehicles to ensure the performance, longevity, and safety of lithium-ion batteries. Thermal management systems must be lightweight to improve vehicle efficiency and robust enough to operate effectively at high temperatures like 40 °C. However, research on cooling systems that focuses on reducing weight, minimizing power consumption, and ensuring performance and battery health in high temperatures is limited but crucial for the industry. This study proposes a lightweight T-shaped cold plate for the 60Ah pouch cell, and its capabilities are demonstrated at the cell level through experiments performed at high ambient temperatures of 40 °C and 35 °C during 1C charging and 2C discharging cycles. The scalability of the T-shaped cold plate is further validated by extending the design from the cell level to the module level using numerical studies. Performance metrics are developed to optimize coolant mass flow rate and inlet temperature, balancing battery health and energy consumption. An optimal mass flow rate of 7 kg/h and inlet temperature of 35 °C is identified for both 40 °C and 35 °C ambient conditions. The intermittent coolant supply reduced energy consumption by 36.9 % and 59 % compared to continuous cooling at 40 °C and 35 °C ambient temperatures, respectively. Additionally, this intermittent supply minimized temperature heterogeneity on the cell surface to 3 °C and 2.1 °C for 40 °C and 35 °C ambient temperatures, respectively. At the module level, T-shaped cold plates keep the temperature rise below 45 °C using a scaled-up mass flow rate of 35 kg/h and an inlet temperature of 35 °C in a 40 °C ambient condition. The T-shaped cold plate structures constitute 20.7 % of the total module weight and offer scalability to pack-level applications. This makes the TCP a potential solution for lightweight and efficient thermal management in electric vehicles, fostering the electrification journey.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"266 ","pages":"Article 125756"},"PeriodicalIF":6.1,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169371","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":"Optimisation analysis by numerical simulation of adding internal fins in photovoltaic/thermal system based on Taguchi method","authors":"Hongmin Liu,&nbsp;Wenbo Zhu","doi":"10.1016/j.applthermaleng.2025.125635","DOIUrl":"10.1016/j.applthermaleng.2025.125635","url":null,"abstract":"<div><div>The fins have become a popular research topic for PV/T（photovoltaic/thermal） systems due to their excellent heat transfer properties. Due to the large number of fin parameters and variables in PV/T systems, numerical simulation remains an important tool for predicting system performance. In this paper, a three-dimensional numerical model of a PV/T system containing an inner finned tube is developed using ANSYS software. Optimisation of the inner fin structure is essential for improving system performance and predicting optimal parameters. In this paper, Taguchi method was used to investigate the effects of four factors, namely, inner fin width, number of cross-sections, height, and number of intervals, on the performance of the PV/T system, the performance of the hydrothermal fluids, and the distribution of the PV cell and outlet temperature. S/N(signal-to-noise) ratio analysis shows that the height and number of inner fins have a significant effect on system performance. Finally, the optimal parameter combinations for the inner fins are obtained. The thermal, electrical, overall, and overall exergy efficiencies were improved by 12.28 %, 1.31 %, 9.33 %, and 2.16 %, respectively, when the width was 0.2 mm, the number of pieces was 8, the height was 2.5 mm, and the number of intervals was 4. Further, this paper investigates the variation of the system under the optimal inner fin structure for four external conditions. The PV cell temperature decreased by 1.95–3.52 K and the outlet temperature increased by 0.31 K-1.41 K over the studied operating range. The results of this study provide new ideas for the structural design and optimisation of PV/T systems.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"266 ","pages":"Article 125635"},"PeriodicalIF":6.1,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143169867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Numerical analysis of supersonic flow through dry-ice blasting nozzles: Comparative study of nozzle designs and particle transport efficiency","authors":"Aleksandra Dzido,&nbsp;Piotr Krawczyk","doi":"10.1016/j.applthermaleng.2025.125749","DOIUrl":"10.1016/j.applthermaleng.2025.125749","url":null,"abstract":"<div><div>Dry ice blasting is an effective method for industrial dirt removal. This cleaning technique is based on treating contaminated surfaces with a high-speed mixture of dry-ice and air. The dry ice blasting mechanism operates through three main phenomena: thermal effects (cooling), abrasion due to kinetic energy, and sublimation. The final force impacting the cleaning surface is the sum of three components: the force of compressed air, the force exerted by solid CO₂ particles due to their velocity, and the sublimation force resulting from a sudden phase change accompanied by rapid volume expansion. One of the critical factors related to this cleaning mechanism are the blasting mixture parameters. The primary system component influencing these parameters is the nozzle. This study aimed to compare different nozzles’ geometries, particularly in the terms of their effect on dry-ice particle behaviour. To achieve this, a mathematical model of supersonic, two-phase flow with particle–wall collision and mass consumption was developed and implemented in the Ansys CFX numerical environment. A key aspect of the modelling process was accurately simulating dry-ice particles, as their behaviour in a supersonic nozzle has not been thoroughly described in the literature to date. Particle transport efficiency depends on the nozzle geometry, inlet pressure, and particle size. Typical efficiency values for the nozzles considered in this study exceed 85 %, with a maximum efficiency of 91.1 % achieved using nozzle A at an inlet pressure of 4 bar. The lowest efficiencies (highest loses) were observed for particles with a diameter of 250 µm in all cases. The cleaning zone was defined as the region 15–30 cm from the nozzle outlet. In this section, particle velocities range from 50 to 150 m/s depending on the distance, particle diameter, and nozzle geometry. The developed model can serve as a valuable tool for assessing new nozzle geometries.</div></div>","PeriodicalId":8201,"journal":{"name":"Applied Thermal Engineering","volume":"266 ","pages":"Article 125749"},"PeriodicalIF":6.1,"publicationDate":"2025-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143168655","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}