International Journal of Turbomachinery, Propulsion and Power最新文献_第8页

Axial Impeller-Only Fans with Optimal Hub-to-Tip Ratio and Blades Adapted for Minimum Exit Loss 具有最佳轮毂与叶尖比和适应最小出口损失的叶片的轴流叶轮风扇

IF 1.4

International Journal of Turbomachinery, Propulsion and Power Pub Date : 2023-03-01 DOI: 10.3390/ijtpp8010007

T. Carolus, K. Bamberger

{"title":"Axial Impeller-Only Fans with Optimal Hub-to-Tip Ratio and Blades Adapted for Minimum Exit Loss","authors":"T. Carolus, K. Bamberger","doi":"10.3390/ijtpp8010007","DOIUrl":"https://doi.org/10.3390/ijtpp8010007","url":null,"abstract":"This study targets determining impellers of impeller-only axial fans with an optimal hub-to-tip ratio for the highest achievable total-to-static efficiency. Differently from other studies, a holistic approach is chosen. Firstly, the complete class of these fans is considered. Secondly, the radial distribution of blade sweep angle, stagger angle, chord length, and camber are varied to adapt the blades to the complex flow in the hub and tip regions. The tool being used is an optimization scheme with three key components: (i) a database created beforehand by Reynolds-averaged Navier–Stokes (RANS)-predicted performance characteristics of 14,000 designs, (ii) an artificial neural network as a metamodel for the fan performance as a function of 26 geometrical parameters, and (iii) an evolutionary algorithm for optimization, performed on the metamodel. Typically, the hub-to-tip ratios for the impellers proposed by the optimization scheme are smaller than those obtained by applying the classic design rules. A second outcome are the shapes of the blades, which are adapted for a minimum exit loss. These shapes deviate substantially from the classic and even the state-of-the-art “swept-only” or “swept with dihedral” designs. The chord length, stagger, and sweep angle are distributed from hub to tip in a complex manner. The inherent reason is that the scheme tries to minimize not only the dynamic exit loss but also frictional losses due to secondary flows in the hub and tip regions, which eventually results in the maximum achievable total-to-static efficiency. Upon request, the authors will provide the full geometry of the four impellers analysed in some detail in this study to any individual for experimental validation or further analysis of their performance.","PeriodicalId":36626,"journal":{"name":"International Journal of Turbomachinery, Propulsion and Power","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46193365","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

Numerical Determination of the Equivalent Sand Roughness of a Turbopump’s Surface and Its Roughness Influence on the Pump Characteristics 涡轮泵表面等效砂粗糙度的数值确定及其对泵特性的影响

IF 1.4

International Journal of Turbomachinery, Propulsion and Power Pub Date : 2023-02-07 DOI: 10.3390/ijtpp8010005

B. Torner, Deborah Duong, F. Wurm

{"title":"Numerical Determination of the Equivalent Sand Roughness of a Turbopump’s Surface and Its Roughness Influence on the Pump Characteristics","authors":"B. Torner, Deborah Duong, F. Wurm","doi":"10.3390/ijtpp8010005","DOIUrl":"https://doi.org/10.3390/ijtpp8010005","url":null,"abstract":"The correct computation of flows over rough surfaces in technical systems, such as in turbomachines, is a significant issue for proper simulations of their performance data. Once the flow over rough surfaces is adequately computed in these machines, simulations become more trustworthy and can replace experimental prototyping. Roughness modelling approaches are often implemented in a solver to account for roughness effects in flow simulations. In these approaches, the equivalent sand roughness ks must be defined as a characteristic parameter of the rough surface. However, it is difficult to determine the corresponding ks-value for a surface roughness. In this context, this paper shows a novel and time-efficient numerical method, the discrete porosity method (DPM), which can be used to determine the ks-value of a rough surface. Applying this method, channel flow simulations were performed with an irregularly distributed cast iron surface from a turbopumps volute. After identifying the fully rough regime, the equivalent sand roughness was determined and a match with ks-values from literature data was found. Subsequently, the established ks-value for cast iron was used in a turbopump simulation with rough walls. The performance data of the pump were validated by experiments and a good agreement between the experimental and simulated performance data was found.","PeriodicalId":36626,"journal":{"name":"International Journal of Turbomachinery, Propulsion and Power","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41838596","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: 2

Exergy-Based Efficiency Assessment of Fans vs. Isentropic Efficiency 基于火用的风机效率评估与等熵效率

IF 1.4

International Journal of Turbomachinery, Propulsion and Power Pub Date : 2023-02-06 DOI: 10.3390/ijtpp8010004

Johannes Brötz, C. Schänzle, P. Pelz

{"title":"Exergy-Based Efficiency Assessment of Fans vs. Isentropic Efficiency","authors":"Johannes Brötz, C. Schänzle, P. Pelz","doi":"10.3390/ijtpp8010004","DOIUrl":"https://doi.org/10.3390/ijtpp8010004","url":null,"abstract":"The efficiency definition allows us to compare two machines with each other. In general, the efficiency is defined as the ratio of usable power to the required power. This raises the question: what is the usable power? Most engineers discuss efficiency on the basis of the energy balance, i.e., the first law of thermodynamics. In this paper, we derive the exegetic efficiency taking the second law of thermodynamics into account. Exergy analysis takes into account work and heat and is able to model reality very accurately. On this basis, a comparison between the isentropic and exergetic efficiencies is given. A high-pressure radial fan is used as an example, and the differences are discussed. Therefore, measurements of a non-adiabatic fan are evaluated, and the role of the heat flux in the environment is discussed. The investigations show that a relevant difference between the isentropic and exergetic efficiencies becomes apparent in the partial-load range with high-pressure build-up. The thermal energy contained in the flow belongs proportionally to the exergy, i.e., the working capacity of the gas relative to its environment. For a standard such as ISO 5801 “Fans—Performance testing using standardized airways”, the efficiency must not only be physically correct, it must also be simple and practical. Against this background, the outlook of this paper discusses when and which efficiency definition is appropriate and best suited for a standard.","PeriodicalId":36626,"journal":{"name":"International Journal of Turbomachinery, Propulsion and Power","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49408131","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

Data-Driven Anomaly Detection Framework for Complex Degradation Monitoring of Aero-Engine 航空发动机复杂退化监测的数据驱动异常检测框架

IF 1.4

International Journal of Turbomachinery, Propulsion and Power Pub Date : 2023-02-01 DOI: 10.3390/ijtpp8010003

Zichen Yan, Jianzhong Sun, Yang Yi, Caiqiong Yang, Jingbo Sun

引用次数: 1

Acknowledgment to the Reviewers of IJTPP in 2022 对2022年IJTPP评审员的致谢

IF 1.4

International Journal of Turbomachinery, Propulsion and Power Pub Date : 2023-01-20 DOI: 10.3390/ijtpp8010002

引用次数: 0

Active Turbulence Grid-Controlled Inflow Turbulence and Replication of Heat Exchanger Flow Fields in Fan Applications 主动湍流网格控制的入流湍流和风机应用中换热器流场的复制

IF 1.4

International Journal of Turbomachinery, Propulsion and Power Pub Date : 2023-01-04 DOI: 10.3390/ijtpp8010001

F. Czwielong, S. Becker

{"title":"Active Turbulence Grid-Controlled Inflow Turbulence and Replication of Heat Exchanger Flow Fields in Fan Applications","authors":"F. Czwielong, S. Becker","doi":"10.3390/ijtpp8010001","DOIUrl":"https://doi.org/10.3390/ijtpp8010001","url":null,"abstract":"A novel active turbulence grid of the Institute of Fluid Mechanics at FAU Erlangen-Nuremberg is introduced. The focus of this grid is not on basic investigations of fluid mechanics, as is usually the case with active turbulence grids, but the generation of defined inflow conditions for axial fans. Thus, by means of the active turbulence grid, individual turbulence characteristics in the flow to the fan can be changed; therefore, fundamental interactions between the flow mechanics at the axial fan and the sound radiation can be analyzed. In addition, the replication of the flow fields of heat exchangers by the active turbulence grid is the focus of the investigations. The investigations showed that it is possible to use the active turbulence grid to generate defined inflow conditions for axial fans. It was also possible to reproduce the heat exchanger flow fields both for the mean turbulence values and for the spatial distributions. It was found that the grid induces tonal components due to the drive motors, but also that the inherent noise has no significant influence on the spectrum of the fans under investigation. Based on selected turbulence characteristics, direct correlations were found between the spatial distribution of the turbulence level and sound radiation at the first blade passing frequency of the axial fan. As the variance of the turbulence level increases, the sound radiation of the tonal components becomes more pronounced. The total sound pressure level, however, is mainly determined by the low-frequency broadband sound. A linear relationship between the spatial mean value of the turbulence level and the total sound pressure level was found for the investigated axial fan.","PeriodicalId":36626,"journal":{"name":"International Journal of Turbomachinery, Propulsion and Power","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43859452","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

Investigations concerning the Flow Stabilization of Backward Curved Centrifugal Impellers at Low Flow Rate 后向弯曲离心叶轮在低流速下的流动稳定性研究

IF 1.4

International Journal of Turbomachinery, Propulsion and Power Pub Date : 2022-12-07 DOI: 10.3390/ijtpp7040037

F. Lörcher, S. Hub, M. Sanjosé, S. Moreau

引用次数: 0

Fans: Noise, Aerodynamics, Applications and Systems—The Best of the International Conference FAN2022 风扇:噪音，空气动力学，应用和系统-最佳国际会议FAN2022

IF 1.4

International Journal of Turbomachinery, Propulsion and Power Pub Date : 2022-12-02 DOI: 10.3390/ijtpp7040036

T. Carolus

引用次数: 0

Uniformity Index as a Universal Air-Cooled Condenser Fan Performance Metric 作为通用风冷冷凝器风扇性能指标的均匀性指数

IF 1.4

International Journal of Turbomachinery, Propulsion and Power Pub Date : 2022-12-01 DOI: 10.3390/ijtpp7040035

F. Marincowitz, M. Owen, J. Muiyser, Peter Holkers

{"title":"Uniformity Index as a Universal Air-Cooled Condenser Fan Performance Metric","authors":"F. Marincowitz, M. Owen, J. Muiyser, Peter Holkers","doi":"10.3390/ijtpp7040035","DOIUrl":"https://doi.org/10.3390/ijtpp7040035","url":null,"abstract":"Ambient wind has a negative effect on mechanical forced-draft direct air-cooled steam condenser (ACC) fan volumetric performance, and increases dynamic fan blade loading. Investigating these effects directly using on-site measurement or numerical analysis is complicated, and most previous work has focused on only one effect at the expense of the other. In this study, fan axial velocity inflow uniformity is identified as a single metric offering the potential to holistically qualify ACC fan operation under windy conditions. A 3 × 6 fan cell ACC was modelled with CFD using a blade element theory-based fan model, and clear relationships between the fan inflow uniformity index and both fan volumetric performance and dynamic blade loading were observed in the results. The same relationships were observed in on-site test data collected at a single ACC fan, thus validating the numerical results. The uniformity index can be used in both numerical and experimental work as a means of investigating both fan volumetric performance and dynamic blade loading with less computational and measurement complexity; it also offers a potentially useful means of quantifying the severity of fan operating conditions, to assist with more reliable case-specific fan design and selection.","PeriodicalId":36626,"journal":{"name":"International Journal of Turbomachinery, Propulsion and Power","volume":null,"pages":null},"PeriodicalIF":1.4,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48105763","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

Effect of Sweep on Axial Fan Noise Sources Using the Lattice Boltzmann Method 用晶格玻尔兹曼方法研究扫描对轴流风扇噪声源的影响

IF 1.4

International Journal of Turbomachinery, Propulsion and Power Pub Date : 2022-11-22 DOI: 10.3390/ijtpp7040034

D. Ghodake, M. Sanjosé, S. Moreau, M. Henner

引用次数: 1