Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2最新文献_第3页

Vibration Analysis and Methods of Dry Friction Damping of Tubed Vortex Reducer 管式减速器的振动分析及干摩擦阻尼方法

Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2 Pub Date : 2020-09-21 DOI: 10.1115/GT2020-14001

Siyuan Chen, Yanrong Wang, D. Wei, Yanbin Luo, S. Gao

{"title":"Vibration Analysis and Methods of Dry Friction Damping of Tubed Vortex Reducer","authors":"Siyuan Chen, Yanrong Wang, D. Wei, Yanbin Luo, S. Gao","doi":"10.1115/GT2020-14001","DOIUrl":"https://doi.org/10.1115/GT2020-14001","url":null,"abstract":"\u0000 The tubed vortex reducer is a new structure of aero-engine, which is widely used in advanced large bypass ratio high performance turbofan engines. It is usually installed between the rear two-stage discs of the high-pressure compressor, and reduces the generation of free vortex by restricting the flow path of the cooling airflow, thereby reducing the pressure loss of the cooling airflow and improving the engine efficiency. In this paper, vibration analysis of tubed vortex reducer is carried out by experiments and numerical simulations. Using the finite element method, the natural vibration characteristics of the vortex reducer are calculated with ANSYS. The sensitivity analysis of the impact of design parameters on the vibration characteristics is carried out. In addition, the vibration test bench of the vortex reducer is set up, and the vibration test of the vortex reducer is conducted by means of frequency sweeping and hammer hitting respectively. The experimental results satisfactorily reproduce the simulation results. Then the theoretical model of dry friction damping of vortex reducer is established. Based on the dynamic model of the complex contact system composed of vortex reducer and damping sleeve, the relationship between energy dissipation in different directions is derived. And a method evaluating the performance of vibration reduction is presented for calculating its equivalent damping ratio. Finally, the influence of the key design parameters and different installation methods on the damping ratio is analyzed. Overall, this work can provide reference for vibration reduction design and optimization of vortex reducer.","PeriodicalId":186943,"journal":{"name":"Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126604622","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

Development and Testing of a 10 MWe Supercritical CO2 Turbine in a 1 MWe Flow Loop 10mwe超临界CO2涡轮在1mwe流动回路中的开发与测试

Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2 Pub Date : 2020-09-21 DOI: 10.1115/GT2020-15945

J. Moore, Stefan D. Cich, Meera Day-Towler, J. Mortzheim

{"title":"Development and Testing of a 10 MWe Supercritical CO2 Turbine in a 1 MWe Flow Loop","authors":"J. Moore, Stefan D. Cich, Meera Day-Towler, J. Mortzheim","doi":"10.1115/GT2020-15945","DOIUrl":"https://doi.org/10.1115/GT2020-15945","url":null,"abstract":"\u0000 sCO2 power cycles offer improved cycle efficiencies compared with traditional steam Rankine cycles. However, the turbomachinery required to support such a cycle does not exist at a commercial scale and requires development. This paper describes a new 10 MWe scale sCO2 turbine was developed and demonstrated in an sCO2 closed-loop recompression Brayton cycle. Since this turbine was developed for Concentrating Solar Power (CSP) applications, a target inlet temperature of over 700°C was chosen using funding from the US DOE SunShot initiative and industry partners. However, it can be applied to traditional heat sources such as natural gas, coal, and nuclear power. Traditional Rankine steam cycle thermal efficiencies are typically in the 35–40% range, but can be as high as 45% for advanced ultra-supercritical steam cycles. The sCO2 cycle can approach 50% thermal efficiency using externally fired heat sources. Furthermore, this cycle is also well suited for bottoming cycle waste heat recovery applications, which typically operate at lower temperatures. The high-power density and lower thermal mass of the sCO2 cycle results in compact, high-efficiency power blocks that can respond quickly to transient environmental changes and transient operation, a particular advantage for solar, waste heat, and ship-board applications. The power density of the turbine is significantly greater than traditional steam turbines and is comparable to liquid rocket engine turbo pumps. This paper describes the design and construction of the turbine and provides additional testing of the 10 MWe turbine in a 1 MWe test facility including a description of rotordynamics, thermal management, rotor aero and mechanical design, shaft-end and casing seals, bearings, and couplings. Test data for the turbine is included, as it achieves its operational goal of 715°C, 250 bara, and 27,000 rpm.","PeriodicalId":186943,"journal":{"name":"Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2","volume":"290 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115234824","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: 1

Effect of Friction on the Structural Dynamics of Built-Up Structures: An Experimental Study 摩擦对组合结构动力学影响的实验研究

Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2 Pub Date : 2020-09-21 DOI: 10.1115/GT2020-14945

A. Fantetti, C. Schwingshackl

{"title":"Effect of Friction on the Structural Dynamics of Built-Up Structures: An Experimental Study","authors":"A. Fantetti, C. Schwingshackl","doi":"10.1115/GT2020-14945","DOIUrl":"https://doi.org/10.1115/GT2020-14945","url":null,"abstract":"\u0000 Frictional contacts are a major source of uncertainty in the correct prediction of the dynamic response of built-up structures. This uncertainty is partially due to a limited understanding of the effects of friction on dynamic responses. Vice versa, dynamic responses can also affect the frictional behaviour of the interfaces in contact.\u0000 In the present study, the mutual relationships between frictional behaviour and structural dynamics are investigated by means of a high frequency friction rig. The rig is characterised by a simple and localised frictional contact that is needed to accurately measure hysteresis loops. Of course, the rig also has its own dynamic response, and consequently represents an excellent test case to gain a better understanding of the correlation between hysteresis loop shapes and their effect upon the dynamics.\u0000 Impact hammer tests and shaker tests were performed on the friction rig, and lead to changes in the damping and stiffness of its dynamic response, which were linked to variations in the frictional behaviour of the contact. Furthermore, there was some indication as to how certain resonances of the system might strongly affect the frictional behaviour. In particular, it was observed that full sliding causes excitation of structural modes that in turn lead to distortions in the measured hysteresis loops.\u0000 These findings confirm the strong relationship between friction and dynamics, thus highlighting the necessity to include a detailed frictional description of contacting interfaces for more accurate modelling of the dynamics of built-up structures.","PeriodicalId":186943,"journal":{"name":"Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125736392","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: 8

An Energy Method for Assessing the Damping of Turbine Blade Underplatform Damper and Forced Response Verification 涡轮叶片平台下减振器阻尼评估的能量法及强迫响应验证

Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2 Pub Date : 2020-09-21 DOI: 10.1115/GT2020-14532

S. Gao, Yanrong Wang, Z. Sun

{"title":"An Energy Method for Assessing the Damping of Turbine Blade Underplatform Damper and Forced Response Verification","authors":"S. Gao, Yanrong Wang, Z. Sun","doi":"10.1115/GT2020-14532","DOIUrl":"https://doi.org/10.1115/GT2020-14532","url":null,"abstract":"\u0000 Rotating turbine blades in aircraft gas turbines are subject to high loads which can result in high cycle fatigue (HCF) failure. In order to reduce the vibration of blades, underplatform dampers are widely used to increase the damping by dry friction dissipating the vibration energy. This paper proposes an energy method (EM) for assessing the damping effect of underplatform dampers with the contacts of one cylinder and one flat without calculating the forced response. In this method the characteristic curve of the damping ratio of the damper on the vibration stress of the blade is used to design the damper. The design objective is that the damper can provide an optimal damping ratio on a given range of vibration stress if resonance occurs. This paper proposes a method for calculating the response and the performance plot based on the above characteristic curve to compare with Direct Time Integration (DTI). The effects of parameters such as contact stiffness, modal data and rotation speed, friction coefficient, damper mass on the damping ratio characteristics are analyzed. Based on the allowable vibration stress of the blade, the design process of the underplatform dampers using damping ratio characteristic curve is given. The proposed method is suitable and efficient for situations where the presence of the damper does not greatly affect the mode shape of the blade.","PeriodicalId":186943,"journal":{"name":"Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123953391","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: 1

Non-Uniform Two-Phase Flow of Supercritical Carbon Dioxide Centrifugal Compressor 超临界二氧化碳离心压缩机的非均匀两相流

Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2 Pub Date : 2020-09-21 DOI: 10.1115/GT2020-14285

W. Bao, Ce Yang, L. Fu, Changmao Yang, L. Ji

{"title":"Non-Uniform Two-Phase Flow of Supercritical Carbon Dioxide Centrifugal Compressor","authors":"W. Bao, Ce Yang, L. Fu, Changmao Yang, L. Ji","doi":"10.1115/GT2020-14285","DOIUrl":"https://doi.org/10.1115/GT2020-14285","url":null,"abstract":"\u0000 An asymmetric structure of volute in a supercritical carbon dioxide centrifugal compressor induces a non-uniform circumferential distribution of the upstream flow field, which inevitably affects the formation of a two-phase region of carbon dioxide in an impeller. In this work, unsteady simulations for centrifugal compressors were conducted. First, the influence of low static strip induced by low static pressure near volute tongue on the impeller flow field was presented. Then, the non-uniform flow field distribution in the impeller passages and flow characteristics of the passages at the impeller inlet were obtained. Finally, the two-phase regions in the impeller were presented. The results demonstrate that for a centrifugal compressor with volute, the two-phase region appears not only on the suction surface of the leading edge of the blade, but also in some impeller passages, on the pressure surface of the blade near the leading edge, and in the leading edge and mid-chord of tip clearance, under the design conditions. The low static pressure strip induced by the volute leads to a high-speed region in the impeller passages where the temperature and pressure of supercritical carbon dioxide fall below the critical point and carbon dioxide enters the two-phase region. Meanwhile, the static pressure on the blade surface is distorted under the influence of a high-speed region in the passages, resulting in the formation of a two-phase region at the tip clearance. The flow distortion of passages at the impeller inlet results in the appearance of two-phase regions on the both sides of leading edge of the blade. The dryness on the suction side of the blade leading edge and the leading edge of the tip clearance is lower, which indicated that the proportion of liquid-phase carbon dioxide is higher in these two-phase regions.","PeriodicalId":186943,"journal":{"name":"Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126983466","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

A Design Tool for Supercritical CO2 Radial Compressors Based on the Two-Zone Model 基于双区模型的超临界CO2径向压缩机设计工具

Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2 Pub Date : 2020-09-21 DOI: 10.1115/GT2020-15248

Ihab Abd El Hussein, A. Hacks, S. Schuster, D. Brillert

{"title":"A Design Tool for Supercritical CO2 Radial Compressors Based on the Two-Zone Model","authors":"Ihab Abd El Hussein, A. Hacks, S. Schuster, D. Brillert","doi":"10.1115/GT2020-15248","DOIUrl":"https://doi.org/10.1115/GT2020-15248","url":null,"abstract":"\u0000 In supercritical Carbon Dioxide (sCO2) cycles, the compressor inlet conditions are selected near the critical point where compressibility factor reaches values as low as 0.2. Consequently, conventional compressor design approaches formulated for fluids obeying the ideal gas law are not verified. Therefore, this paper proposes a design approach for sCO2 radial compressors that consists of a performance prediction model in addition to a set of geometry parameters suitable for radial compressors. The compressor model is based on the two-zone modeling approach, in which the Span and Wagner equation of state for CO2 is integrated. At first, the compressor model is presented in addition to the required correlations. Afterwards, a sensitivity analysis is performed on the model main parameters. Thereafter, a plausibility check is performed against experimentally obtained data. Finally, an overall design approach is proposed and its capability to deliver new geometries is assessed by comparing the tool predictions against the results from a verified CFD code for several test cases. The Comparison shows a maximum deviation of less than 2 percent for the pressure ratio and less than 3.5 percentage points for the efficiency. The results indicate the ability of the proposed approach to predict the performance of sCO2 compressor from correlations that originate from experience with conventional fluids. Additionally, the adopted geometric relations proved its applicability to sCO2 compressors.","PeriodicalId":186943,"journal":{"name":"Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2","volume":"96 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133699985","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: 3

Multi-Channel Spectral Analysis of Non-Synchronous Vibrations of Bladed Disks Measured by Blade Tip Timing 叶尖定时测量叶片非同步振动的多通道频谱分析

Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2 Pub Date : 2020-09-21 DOI: 10.1115/GT2020-15512

L. Carassale, F. Coletti, R. Guida, Michela Marrè-Brunenghi, Elena Rizzetto

引用次数: 0

Sparse Reconstruction Method of Non-Uniform Sampling and its Application in Blade Tip Timing System 非均匀采样稀疏重建方法及其在叶尖定时系统中的应用

Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2 Pub Date : 2020-09-21 DOI: 10.1115/GT2020-14753

J. Tian, Xiaopu Zhang, Yong Chen, P. Russhard, H. Ouyang

{"title":"Sparse Reconstruction Method of Non-Uniform Sampling and its Application in Blade Tip Timing System","authors":"J. Tian, Xiaopu Zhang, Yong Chen, P. Russhard, H. Ouyang","doi":"10.1115/GT2020-14753","DOIUrl":"https://doi.org/10.1115/GT2020-14753","url":null,"abstract":"\u0000 Based on the blade vibration theory of turbomachinery and the basic principle of blade timing systems, a sparse reconstruction model is derived for the tip timing signal under an arbitrary sensor circumferential placement distribution. The proposed approach uses the sparsity of the tip timing signal in the frequency domain. The application of compressive sensing in reconstructing the blade tip timing signal and monitoring multi-mode blade vibrations is explored. To improve the reconstruction effect, a number of numerical experiments are conducted to examine the effects of various factors on synchronous and non-synchronous signals. This enables the specific steps involved in the compressive sensing reconstruction of tip timing signals to be determined. The proposed method is then applied to the tip timing data of a 27-blade rotor. The results show that the method accurately identifies the multi-mode blade vibrations at different rotation speeds. The proposed method has the advantages of low dependence on prior information, insensitivity to environmental noise, and simultaneous identification of synchronous and non-synchronous signals. The experimental results validate the effectiveness of the proposed approach in engineering applications.","PeriodicalId":186943,"journal":{"name":"Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122367409","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

Numerical Analysis of Mass Flow Leakage Through Orifices for Supercritical CO2: Two-Phase Flow Effects 超临界CO2孔口质量流量泄漏的数值分析:两相流效应

Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2 Pub Date : 2020-09-21 DOI: 10.1115/GT2020-15927

L. Vesely, Akshay Khadse, Andres Curbelo, J. Kapat, Luca Petrungaro

{"title":"Numerical Analysis of Mass Flow Leakage Through Orifices for Supercritical CO2: Two-Phase Flow Effects","authors":"L. Vesely, Akshay Khadse, Andres Curbelo, J. Kapat, Luca Petrungaro","doi":"10.1115/GT2020-15927","DOIUrl":"https://doi.org/10.1115/GT2020-15927","url":null,"abstract":"\u0000 Supercritical CO2 (sCO2) holds a great promise as a future working fluid for power generating Brayton cycles. One of the challenging research areas in sCO2 power cycles is flow leakage and the design of seals on the compressor side of the cycle. Given the compact nature of sCO2 turbomachinery, even a minimal amount of leakage can lead to a significant power efficiency loss. Hence accurate prediction of mass flow leakage rate becomes important. However, on the compressor side of the cycle, operating conditions across the seal lead to two-phase flow. This makes flow modeling very challenging because conventional one-phase flow CFD models cannot be used. This paper is an attempt to understand the behavior of two-phase sCO2 flow going through circular and annular orifices. The focus is to utilize commercially available CFD scheme for modeling phase change and two-phase flow through constrictions. Since the pressure loss across constrictions is also accompanied with reduction in temperature, the flow becomes two-phase by entering the saturation dome. CFD simulation is performed using commercially available software STAR CCM+. 2D axisymmetric geometry is considered as the computational domain. Eulerian Multi-phase Mixture model is used in conjunction with the Two-Phase Thermodynamic Equilibrium implementation. This model is intended for applications that involve two phases of the same substance that are in thermodynamic equilibrium. Fluid properties are defined over a large range of temperatures and pressures, including both the liquid and vapor phases.","PeriodicalId":186943,"journal":{"name":"Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121960367","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

Introductory PZT Actuators Optimal Working Configuration Experimental Study in a Turbofan Engine Fan Rotor Blade 涡扇发动机风扇转子叶片PZT作动器优化工作结构试验研究

Volume 11: Structures and Dynamics: Structural Mechanics, Vibration, and Damping; Supercritical CO2 Pub Date : 2020-09-21 DOI: 10.1115/GT2020-15547

F. Botta, A. Rossi

引用次数: 1