한국유체기계학회 논문집最新文献

Hydraulic Characteristics of a Single-channel Pump Designed by the Affinity Law 基于亲和规律设计的单通道泵的水力特性

한국유체기계학회 논문집 Pub Date : 2023-10-31 DOI: 10.5293/kfma.2023.26.5.007

Duc-Anh Nguyen, Min-Su Roh, Sung Kim, Soon-Young Jeong, Jin-Hyuk Kim

{"title":"Hydraulic Characteristics of a Single-channel Pump Designed by the Affinity Law","authors":"Duc-Anh Nguyen, Min-Su Roh, Sung Kim, Soon-Young Jeong, Jin-Hyuk Kim","doi":"10.5293/kfma.2023.26.5.007","DOIUrl":"https://doi.org/10.5293/kfma.2023.26.5.007","url":null,"abstract":"Recently single-channel pumps are widely applied for wastewater treatment in Korea. To be able to apply this type of pump in the world, which is different in power frequency, this study uses the affinity law to redesign the impeller geometry of the single-channel pump optimized from the previous work. Meanwhile, the volute is designed by two methods which are the affinity law and the cutting diameter method. The numerical approach is performed by using steady and unsteady Reynolds-averaged Navier-Stokes equations and a shear stress transport reattachment modification (SST k-ω) turbulence model. The hydraulic efficiency curves and internal flow field including contours and streamlines are investigated and evaluated thoroughly. The numerical result is verified by the experimental test based on the 11SUPth/SUPAPI610 standard. At the design flow rate condition, the novel pump models meet the design requirement with a minimum total head coefficient. The efficiency of the novel models remains almost unchanged compared to the base model. The sweep area of the unsteady radial force distribution in the novel models is smaller than that of the base model at low flow rate and design flow rate conditions while at high flow rate conditions show the opposite. In addition, the distance between the center of the radial force and the origin of the novel models is also reduced compared to the base model. The pressure amplitudes of the novel models are also decreased significantly. These improvements in the novel models mostly result in the reduction in noise and vibration in pump operation.","PeriodicalId":491641,"journal":{"name":"한국유체기계학회 논문집","volume":"37 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135928502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Application of Deep Learning for Quantifying Small RCS Leakage 深度学习在RCS小泄漏量化中的应用

한국유체기계학회 논문집 Pub Date : 2023-10-31 DOI: 10.5293/kfma.2023.26.5.027

Sang-Hyun Lee, Hye-Seon Jo, Man-Gyun Na

{"title":"Application of Deep Learning for Quantifying Small RCS Leakage","authors":"Sang-Hyun Lee, Hye-Seon Jo, Man-Gyun Na","doi":"10.5293/kfma.2023.26.5.027","DOIUrl":"https://doi.org/10.5293/kfma.2023.26.5.027","url":null,"abstract":"In nuclear power plants, coolant leakage occurs for various reasons. Leak detection is important to ensure safety of nuclear power plants. Currently, a detection system for an unidentified reactor coolant system(RCS) leakage of less than 0.5gpm is being developed in Korea. The RCS leakage is detected through changes in radioactivity, humidity, and temperature in the containment air, and water level of sump. For small leaks, the change in humidity and temperature due to water vapor is very small, making the leak very difficult to detect until the leak accumulates in the instrument.BR In order to solve these problems and increase the leak detection speed, it is necessary to develop a system capable of real-time detection using artificial intelligence. In this study, long short-term memory and bidirectional long short-term memory, which are types of recurrent neural networks among artificial intelligence methods, were applied to perform initial relative humidity prediction for leakage quantification. Also, an optimization technique that reduces learning time and improves prediction performance for the optimization of learning was applied. Finally, the prediction performance was evaluated using the developed model.","PeriodicalId":491641,"journal":{"name":"한국유체기계학회 논문집","volume":"38 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135928501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Study on Aerodynamic Performance Characteristics for SMART BLADE according to Turbulence Model 基于湍流模型的SMART叶片气动性能研究

한국유체기계학회 논문집 Pub Date : 2023-10-31 DOI: 10.5293/kfma.2023.26.5.118

Seong-Chul Park, Kwangtae Ha, Jae-Ho Jeong

{"title":"Study on Aerodynamic Performance Characteristics for SMART BLADE according to Turbulence Model","authors":"Seong-Chul Park, Kwangtae Ha, Jae-Ho Jeong","doi":"10.5293/kfma.2023.26.5.118","DOIUrl":"https://doi.org/10.5293/kfma.2023.26.5.118","url":null,"abstract":"This study presents an analysis of the aerodynamic performance characteristics of 20 m rotor blades for the NREL CART3 wind turbine within the SMART BLADES and SMART BLADES-2 projects. Three-dimensional Computational Fluid Dynamics (CFD) analysis was conducted to investigate the aerodynamic behavior. The Reynolds Averaged Navier-Stokes (RANS)-based turbulence model was utilized for numerical simulations, and the results were compared with Fraunhofer’s Blade Elementary Momentum Theory (BEMT) results. The aerodynamic performance characteristics of the rotor blades were evaluated using three turbulence models: Spalart Allmaras (S-A), standard k-ω, and Shear Stress Transform (SST) k-ω. The turbulence models demonstrated good agreement with the BEMT results at wind speeds below the rated power. However, under rated power wind speed conditions, the S-A and standard k-ω turbulence models exhibited an underprediction of aerodynamic performance. This discrepancy was attributed to an overestimation of the flow delamination point and recirculation region near the blade hub. Therefore, it is recommended to employ the SST k-ω turbulence model, which accurately captures turbulence phenomena both inside and outside the boundary layer, for rated power speed conditions.","PeriodicalId":491641,"journal":{"name":"한국유체기계학회 논문집","volume":"3 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135928506","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Establishment and Evaluation of Leak Collection System Analysis Method Using CFD Analysis 基于CFD分析的集漏系统分析方法的建立与评价

한국유체기계학회 논문집 Pub Date : 2023-10-31 DOI: 10.5293/kfma.2023.26.5.034

Dae-Kyung Choi, Won-Man Park, Dong-Jin Euh, Tae-Soon Kwon, Choengryul Choi

{"title":"Establishment and Evaluation of Leak Collection System Analysis Method Using CFD Analysis","authors":"Dae-Kyung Choi, Won-Man Park, Dong-Jin Euh, Tae-Soon Kwon, Choengryul Choi","doi":"10.5293/kfma.2023.26.5.034","DOIUrl":"https://doi.org/10.5293/kfma.2023.26.5.034","url":null,"abstract":"Suppose a small amount of leakage exceeds the limit of the operating conditions of a nuclear power plant. In that case, losses due to the nuclear power plant shutdown may occur, or accidents due to leakage may occur. Consequently, there has been a need to develop a system capable of quickly detecting even small amounts of leakage, and research has been conducted to address this need. To develop such a system, it is necessary to understand the thermal-hydraulic characteristics of the system. This study established a CFD-based evaluation process for evaluating leak detection systems. A numerical analysis model was used to simulate leakage, and a two-step CFD analysis was performed to assess its applicability. In the first step, a study of the leakage behavior in the insulation material was conducted, and the effect of the gap between the pipe insulation material and the outer cover was evaluated. In the second step, the collection loop was analyzed using the results of the leakage behavior analysis in the insulation as an input condition. The results of this study were used to construct the collection loop experimental device and will help in understanding the heat flow characteristics in the collection loop.","PeriodicalId":491641,"journal":{"name":"한국유체기계학회 논문집","volume":"2 3","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135928663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Thermal Shape Optimization of Canopy Structure for Enhancing Heat Transfer Characteristics due to Natural Circulation 为提高自然循环传热特性的冠层结构热形状优化

한국유체기계학회 논문집 Pub Date : 2023-10-31 DOI: 10.5293/kfma.2023.26.5.099

Seongbin Hong, Ah-mi Park, Jong-Hak Lee, Jae-Ho Jeong

{"title":"Thermal Shape Optimization of Canopy Structure for Enhancing Heat Transfer Characteristics due to Natural Circulation","authors":"Seongbin Hong, Ah-mi Park, Jong-Hak Lee, Jae-Ho Jeong","doi":"10.5293/kfma.2023.26.5.099","DOIUrl":"https://doi.org/10.5293/kfma.2023.26.5.099","url":null,"abstract":"Recently, an increased demand for the development of unmanned systems and surveillance technologies, as well as a rapid increase in demand for high-performance camera sensor, has been observed due to the export and advancement of defense technology. The heat generated by camera sensors is also increasing as a result of camera performance improvement, and the importance of camera can lead to reduces target detection accuracy, misidentification, and camera sensor failure. In this study, an optimal canopy shape inducing the stack effect was designed to enhance the heat removal performance of camera systems installed on naval vessels. Through Computational Fluid Dynamics (CFD) analysis, a reduction of approximately 2.3℃ in the component temperature, measured by maximum temperature inside the camera sensor, was confirmed compared to the existing shape. The improvement in cooling performance is derived from the increased flow rated facilitated by natural convection, and it was observed that natural circulation flow rate significantly increases non-linearly as the curvature radius decrease, with a concurrent 43.76% increase in heat transfer rate. In conclusion, the optimization of camera sensor heat removal performance through natural convection, induced by the optimal design of the canopy, was achieved.","PeriodicalId":491641,"journal":{"name":"한국유체기계학회 논문집","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135928655","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Effects of Impeller Blade Shape and Impeller Disk Side Gap Passage Shape on the Regenerative Blower Performance 叶轮叶片形状和叶轮盘侧间隙通道形状对蓄热风机性能的影响

한국유체기계학회 논문집 Pub Date : 2023-10-31 DOI: 10.5293/kfma.2023.26.5.079

Ujjwal Shrestha, Piljea Kim, Young-Do Choi

引用次数: 0

Effects of Blade Fillet Radius on Aerodynamic Performance and Structural Integrity in a Transonic Centrifugal Compressor 叶片圆角半径对跨声速离心压气机气动性能和结构完整性的影响

한국유체기계학회 논문집 Pub Date : 2023-10-31 DOI: 10.5293/kfma.2023.26.5.072

Yong-Han Shin, Hyun-Su Kang, Youn-Jea Kim

引用次数: 0

Numerical Analysis of Internal Flow and Cavitation Phenomenon for a Mixed-Flow Pump with RANS-based CFD Methodology 基于ranss CFD的混流泵内部流动与空化现象数值分析

한국유체기계학회 논문집 Pub Date : 2023-10-31 DOI: 10.5293/kfma.2023.26.5.020

Hyun-jun An, Yong-in Kim, Jae-ho Jeong

引用次数: 0

Scaling Design of Refrigerant-cooled Thermal-Hydraulic Integral Effect Test Facility for OPR1000 OPR1000冷冷热液整体效果试验装置的标定设计

한국유체기계학회 논문집 Pub Date : 2023-10-31 DOI: 10.5293/kfma.2023.26.5.044

Do-Yeong Lim, In-Cheol Bang

引用次数: 0

Prediction of Honeycomb Labyrinth Seal Performance Using CFD and Artificial Neural Network 基于CFD和人工神经网络的蜂窝迷宫密封性能预测

한국유체기계학회 논문집 Pub Date : 2023-10-31 DOI: 10.5293/kfma.2023.26.5.061

Geun-Seo Park, Min-Seok Hur, Tong-Seop Kim, Dong-Hyun Kim, Il-Young Jung

{"title":"Prediction of Honeycomb Labyrinth Seal Performance Using CFD and Artificial Neural Network","authors":"Geun-Seo Park, Min-Seok Hur, Tong-Seop Kim, Dong-Hyun Kim, Il-Young Jung","doi":"10.5293/kfma.2023.26.5.061","DOIUrl":"https://doi.org/10.5293/kfma.2023.26.5.061","url":null,"abstract":"There is a growing interest in sealing technology, as the demand for gas turbine performance improvements increases. The honeycomb labyrinth seal is the most popular sealing technology, but it takes a lot of time to exactly predict its leakage performance considering various geometrical parameters and operating conditions. This study investigated a method to reduce computational costs involved in predicting the performance of honeycomb labyrinth seals using artificial neural networks(ANN) and computational fluid dynamics(CFD). Firstly, the central composite design, one of the design of experiment(DOE), was used to analyze the effects of various geometrical parameters on the leakage performance. The influences of geometric parameters were comparatively analyzed using a Pareto chart, and it was confirmed that clearance, tooth width, pitch, and honeycomb cell diameter were statistically significant(i.e. influential) parameters. Then, CFD simulation was performed using the combination of the selected geometric parameters and operating conditions, generating the database for the ANN to train. The high accuracy of the ANN’s prediction was confirmed by comparing its results with CFD simulations using mean squared error(MSE) and root mean squared error(RMSE). The MSE and RMSE values for the training data within the generated database were 1.475 × 10SUP-5/SUP and 0.003841, respectively. For the new unseen data, the MSE and RMSE values determined to be were 0.00021 and 0.01452 respectively.","PeriodicalId":491641,"journal":{"name":"한국유체기계학회 논문집","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135928499","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0