Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions最新文献

{"title":"Numerical Observations of a Stall Phenomenon in the NASA CC3 Compressor","authors":"Michael Ni, Gregorio Robles Vega, R. Ni, J. Clark, Michael G. List","doi":"10.1115/gt2022-78911","DOIUrl":"https://doi.org/10.1115/gt2022-78911","url":null,"abstract":"\u0000 Numerical analysis of the transonic NASA CC3 centrifugal compressor stage with vaned diffuser is undertaken and the mechanism for the onset of stall investigated. The analysis methodology employs standard practice numerical methods, the mixing-plane approximation at the rotor-stator interface and periodic boundary conditions within a given row. Simulation results were then compared against full annulus time accurate simulations and the methodologies evaluated for estimation for the onset of stall.\u0000 In the study, steady state and full annulus time accurate simulations were conducted at the 100% design speed, from choke to stall. Many time-resolved simulations “stalled” at pressure ratios where steady state mixing-plane solutions converged. One observation from the time-resolved simulations is that the number of revolutions required for the flow to stall was over 5 revolutions and increased to 9 revolutions closer to the last stable point.\u0000 Integrations of the time-resolved solutions at the onset of stall reveal that the flow field of both the impellers and diffusers are not circumferentially uniform, and a stall “cell” is rotating in the opposite direction of the rotor. However, the “cell” is stationary in the stationary frame of reference thus, it is not a conventional rotating stall.\u0000 There is a notable difference in choke flow between experiment and CFD results, which has been seen by others for this configuration. The reason for the miss is not a focus of this paper, and the numerically predicted unsteady stall point should not be viewed as the exact mechanism for stall within the NASA CC3 experiment, instead this work is to provide a review of standard practice numerical approximations and how cost effective full wheel unsteady analysis can be used to improve transonic compressor design.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"351 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115303533","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}

{"title":"Analysis of Ultra-High Bypass Ratio Turbofan Nacelle Geometries With Conventional and Short Intakes at Take-Off and Cruise","authors":"A. Magrini, Denis Bousi, E. Benini","doi":"10.1115/gt2022-81912","DOIUrl":"https://doi.org/10.1115/gt2022-81912","url":null,"abstract":"\u0000 Turbofan engines with ultra-high bypass ratio require more aggressive nacelle designs to limit the drag and weight associated to the increased fan diameter. Reducing the inlet length-to-diameter ratio appears a possibility for further weight saving and mitigation of the total pressure losses. However, these benefits are counteracted by the higher fan exposure to nonuniform in-flow conditions. In this paper, we compare three nacelle geometries for an ultra-high bypass ratio turbofan with a progressively shorter intake having a length-to-diameter ratio of 0.475, 0.35, and 0.22 and two different compact cowl designs. The complete isolated nacelle model, including the exhaust system and a pylon, is simulated numerically with the fan rotor and stator cascades represented through a body force method, allowing to capture the engine/nacelle interaction. The three geometries are examined at take-off and cruise, measuring the variation of integral metrics related to the inlet performance and the propulsive forces. Although with shorter intakes the total pressure losses and the separation onset are positively impacted at high incidence, a careful shaping of the lip is needed to control the diffusion in the limited axial extension available. The effect on the propulsive forces is found to be limited at take-off for a fully attached flow, whereas at cruise the gross thrust improvement of the more compact nacelle is counterbalanced by a larger drag.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122461935","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}

{"title":"Potential and Evolution of Miniatures Compressed Air Energy Storage Plants Based on Impulse Turbine","authors":"Ayad Al Jubori, Laith A. Al-Sadawi, T. Biedermann, S. Alfarawi","doi":"10.1115/gt2022-82627","DOIUrl":"https://doi.org/10.1115/gt2022-82627","url":null,"abstract":"\u0000 This paper describes the work carried out to develop an impulse turbine for miniatures compressed air system. This study hypothesizes the question; what is the effect of combining an impulse turbine loss model into a compressed air energy storage system analysis? The miniatures power system has lower mass flow rates which lead to a small turbine size. The miniature impulse turbine has relatively low efficiency and is highly sensitive to operating conditions at a low mass flow rate due to all losses in terms of passage, trailing edge, incidence, and clearance becoming higher amounts compared to the total losses of the percentage foundation.\u0000 The development of a novel impulse turbine configuration is presented based on one-dimensional design and three-dimensional simulations. The impulse turbine in single-stage configuration was designed and analyzed for a range of operating conditions in terms of pressures, temperatures, mass flow rate, and rotational speeds. The simulations results showed that the maximum efficiency and power were 65.93% and 4.019 kW respectively with a mass flow rate of 0.2 kg/s. The energy analysis revealed that the system efficiency was 10.3%. The miniature compressed air energy storage system driven by an impulse turbine can be used to generate electricity for small power applications.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117030105","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}

{"title":"Predicting Separated Flow in a Three-Dimensional Prediffuser for Combustor Applications Using Improved Numerical Techniques and Workflow","authors":"Adam Norman, C. Arguinzoni","doi":"10.1115/gt2022-83376","DOIUrl":"https://doi.org/10.1115/gt2022-83376","url":null,"abstract":"\u0000 After the last stage of the high-pressure compressor of gas turbine engines, swirling air enters a prediffuser which attempts to straighten out the flow and convert the dynamic pressure to a static pressure. Before the combustion chamber there is an aerodynamic cowl that, typically, separates the air into three parts. The main path leads to the combustor and supplies air to the fuel nozzles, while the secondary paths branch to the inner and outer diameter shroud passages to be used for cooling processes.\u0000 Numerical tools are widely used in prediffuser design to find the optimum design that converts a large portion of the dynamic pressure to static pressure, with the target to avoid separation. Typical analysis today for combustor aerodynamics are done with large eddy simulations (LES), but for the prediffuser design most of the analysis are done using a Reynold’s average Navier Stokes (RANS) approach.\u0000 The combustor aerodynamic community today, rely on hand-crafted, structured, hexahedral meshes to solve flows inside the prediffuser. Creating a structured mesh can be very time consuming and could delay design evolution depending on the complexity of the prediffuser. Due to the flow complexity at the exit of the prediffuser and the impact that could have on flow split predictions provided to the combustor, Reynold’s stress turbulence models (RSM) are typically used. The combined effort of creating structured meshes, with the difficulty in converging results with RSM can negatively impact design times.\u0000 The effort presented here investigates modeling a true three-dimensional diffuser from Cherry et al. using a Poly-Hexcore mesh topology and the Generalized k-Omega (GEKO) turbulence model. The unstructured Poly-Hexcore meshing workflow does not require any manual meshing operations, utilizes parallel meshing, and can be fully automated to simplify the mesh generation process. The GEKO turbulence model has the flexibility to cover a wide range of flows using free coefficients and can be setup to allow robust capturing of prediffuser flow characteristics. Numerical results are compared to experimental data gathered by Cherry et al. and current numerical best practices.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128284381","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}

{"title":"Evaluation of Various Numerical Methods for Blade Row Interaction in Turbomachinery","authors":"Yangwei Liu, Xiaosong Yong, Yumeng Tang","doi":"10.1115/gt2022-84388","DOIUrl":"https://doi.org/10.1115/gt2022-84388","url":null,"abstract":"\u0000 The flow within turbomachinery is inherently unsteady, thereby the unsteady rotor-stator interaction usually has a large effect on the performance of multistage turbomachines. However, fully unsteady simulations are still too time-consuming for in the routine design of turbomachinery, thus, the steady simulation with mixing-plane method that neglects the interaction is still widely used. Some reduced-order unsteady methods, such as harmonic balance (HB) method and space-time gradient (STG) method, have been proposed to simulate the unsteady periodic flow for the purpose of reducing CPU time consumption with sufficient accuracy. In this work, four mixing-plane methods, the HB method, and the STG method are implemented into the open source CFL3D solver. Effect of these methods on predicting unsteady rotor-stator interaction are evaluated in two flow cases, including a quasi-three-dimensional radial slice of a turbine stage and a 1.5-stage high-speed axial compressor. Results show that both the high-order HB and STG methods own the similar ability as the conventional unsteady simulation in predicting the wake transmitting from upstream to downstream, while the steady mixing-plane methods fail. Numerical results of the 1.5 stage compressor show that the wake of the first row can reach the third blade row. And this phenomenon can be also clearly captured by HB and STG methods. Fourier analysis method is used to analyze the interaction in different blade rows to evaluate various numerical methods.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128798225","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}

{"title":"Aerodynamic Noise Characteristics of Axial Flow Fan in Narrow Space and Noise Reduction Based on Flow Control","authors":"Zonghan Sun, Pengfei Chai, J. Tian, Z. Du, H. Ouyang","doi":"10.1115/gt2022-82141","DOIUrl":"https://doi.org/10.1115/gt2022-82141","url":null,"abstract":"\u0000 The aeroacoustic characteristics of a power module in the electric vehicle charging pile is studied by experimental and numerical methods. In the free field, a single cooling fan mainly emits tonal noise, while the far-field noise of fans in parallel satisfied the superposition of incoherent sound sources. However, when two fans in parallel delivered air into the power module, the noise increased significantly, especially broadband noise. Referring to the power module, a narrow space model with cooling fan supplying air inward is constructed. The computational fluid dynamics (CFD) results show that the mass flow rate of the fan is reduced due to the obstacles downstream, which weakens the heat dissipation performance. Part of the fluid forms reflux, interacts with the fan and strengthens the corner vortex. By setting guide holes on the casing near the flow blockage to arrange flow, the flow resistance is reduced and the total mass flow rate of the fan is increased by 2.5%. The reflux and corner vortex are dispersed, and the vortices develop downstream, thus reducing the interaction with the fan. The predicted tonal sound pressure level (SPL) decreases by 3.2 dBA based on acoustic analogy method. The broadband noise caused by shedding vortex is also predicted and discussed by a semi-empirical model. In the noise reduction experiment of the real power module, combining inlet bellmouth on the fan and guide holes on the casing, the total SPL was significantly reduced by 2.9 dBA. Especially, based on bellmouth, guide holes brought an additional 1.9 dBA tonal noise reduction and 1.0 dBA total SPL reduction. The study indicates that appropriate flow control is important to improve the heat dissipation and reduce noise of the power module. These results are helpful to develop higher power charging system.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123904603","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}

{"title":"Numerical Simulation of Multi-Scale Oil Films on a Rotating Cup Using VOF and Coupled Eulerian Thin-Film-DPM Approaches","authors":"A. Nicoli, K. Singh, R. Jefferson-Loveday, S. Ambrose, S. Mouvanal","doi":"10.1115/gt2022-82533","DOIUrl":"https://doi.org/10.1115/gt2022-82533","url":null,"abstract":"\u0000 In this study, the newly developed Nottingham Gas Turbine and Transmission Research Centre (G2TRC) Bearing Chamber Test Module is presented and investigated computationally. The module houses a rotating cup and shaft configuration in order to simulate the droplet generation processes from an aeroengine bearing. The objective of this paper is to model the thin film that develops over the rotating cup surface, comparing a high-fidelity Volume of Fluid (VOF) approach against the Eulerian Thin-Film Model (ETFM). Whilst a VOF approach has previously demonstrated good accuracy for modelling of films over a rotating surface, the ETFM can provide a comparable solution at a much-reduced computational cost. Simulations are performed over a range of shaft speeds and oil flow rates to represent engine operating conditions. This study presents the very first simulation of an oil film over a rotating cup geometry, with a shaft running through the centre of the cup. Computationally, a VOF periodic sector is compared to ETFM simulations run on an equivalent 30° periodic domain. At planes before the rotating cup edge, both film thicknesses and axial velocities are compared. The high-fidelity VOF simulations demonstrate that with an increase in rotational speed, the film thickness over the rotating cup reduces; whilst an increase in oil flow rate produces a thicker film. Compared to the high-fidelity VOF simulations, the ETFM provides good agreement in terms of both film thickness and axial velocities. Overall, the ETFM is shown to be able to produce a similar film to the VOF approach at a much-reduced computational cost, offering a numerical speed-up of approximately 200 to 300 times.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123634837","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}

{"title":"Acoustic Scattering Behaviour of an Aero Engine Injector: Numerical Investigation Using Compressible CFD and CAA","authors":"Çetin Alanyalıoğlu, Hanna Reinhardt, A. Fischer, Claus Lahiri, C. Hasse","doi":"10.1115/gt2022-82901","DOIUrl":"https://doi.org/10.1115/gt2022-82901","url":null,"abstract":"\u0000 During development of modern lean burn aero engine combustors, prediction and characterization of injector thermoacoustic response plays an important role. The SCARLET (SCaled Acoustic Rig for Low Emission Technologies) test rig fulfills this need by providing acoustically defined upstream and downstream conditions under realistic operating conditions to characterize the acoustic response of full-scale injectors in a single sector setup. This work presents results from the complementary numerical analysis campaign that aims to reproduce the acoustic scattering behaviour as measured in the SCARLET rig. As a first step, non-reacting flow simulations were performed using fully compressible CFD simulations and the CAA (computational aero acoustics) method to compute upstream and downstream acoustic fields. The results obtained are then post-processed based on a multi-microphone method to yield the acoustic scattering matrix, which follows the employed experimental post-processing strategy. Results obtained from both methods show satisfactory agreement with measurements. Geometrical simplifications and their implications on scattering behaviour are investigated to achieve a trade-off between accuracy and geometrical complexity. Both methods are compared in terms of their inherent advantages and disadvantages. Limitations associated with employed models and possible improvements are discussed.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"250 4","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113980806","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}

{"title":"Influence From Nozzle Guide Vane Wakes and Inlet End-Wall Boundary Layers on Turbine Rear Structure Aerodynamics","authors":"Pär Nylander, S. Deshpande, J. Larsson","doi":"10.1115/gt2022-81677","DOIUrl":"https://doi.org/10.1115/gt2022-81677","url":null,"abstract":"\u0000 CFD results can be improved by imposing accurate inlet boundary conditions. A previous paper presented extensive measurements from an engine realistic Turbine Rear Structure (TRS), complemented with CFD results using normal radial profiles (1D) at the inlet [10]. This paper extends stat study with two separate studies, investigating the effect of the upstream Nozzle Guide Vane (NGV) wakes and the inlet end-wall boundary layers. In the first study, simulations are done using full 2D inlet boundary condition, imposing the NGV wakes on the inlet. The second study investigates different inlet end-wall boundary layers. Comparisons with measurements show for some aspects that the upstream Nozzle Guide Vane (NGV) wakes and the inlet end-wall boundary layers are important.\u0000 Predicting upstream forcing from the TRS on the LPT rotor requires a 2D inlet boundary condition. Also, a strong interaction between the incoming NGV wakes and the secondary flow loss-regions at the outlet is found. However, flow quantities like blade loading, outlet swirl, and OGV wakes are well predicted using regular 1D radial inlet profiles.\u0000 How the inlet end-wall boundary layers are modelled have significant impact on secondary flows and outlet swirl. If the full boundary layers are prescribed, the secondary flows are over-predicted. This gives under turning and premature separations. With no inlet boundary layers, secondary flows are well captured and gives better separations, improved outlet swirl and wake predictions. The recommendation is therefore to remove the inlet boundary layers when using the Transition SST k-ω γ-Reθ model in TRS CFD simulations.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127561845","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}

{"title":"Gas Turbine Transition Duct Gap Assessment for Unsymmetrical Thermal Boundary Conditions","authors":"Manoharan Sambandam, S. Colantoni","doi":"10.1115/gt2022-81672","DOIUrl":"https://doi.org/10.1115/gt2022-81672","url":null,"abstract":"\u0000 The transition duct (TD) in a gas turbine (GT) twin shaft variant provides an aerodynamic coupling between its high-pressure gas generator module and low-pressure power module. Since the TD defines the flow passage, it interfaces with the high-pressure rotor and shroud at the forward end and the low-pressure rotor and stator at the aft end. Normally, the GT twin shaft variant is equipped with part-load capability. To fulfill this need and to comply with the emission norms, only desired number of burners, adjacent to each other, are used to burn fuel. Using some of the burners during the GT operation is referred to as staging. The GT operation under staging conditions result in non-uniform temperature distribution in the angular locations at any axial position and thus non-uniform thermal growth in the radial and axial directions. This non-uniform thermal growth in radial and axial direction leads to the interface definition very challenging. During the staging operation, the rotor parts experiences uniform radial and axial growth at all the angular locations. Whereas the interfacing stator parts experience temperature distribution like that of the TD and results in non-uniform thermal growth in the radial and axial directions. Appropriate interface definition is vital for efficient operation of the GT. Any interference condition of the TD with rotating parts result in rubbing and with stationary parts result in thermal binding, impacting the GT normal operation. Any generous gap adversely impacts the GT performance due to consumption of more cooling medium. Thus, an assembly gap which results in no interference and consumption of less cooling medium throughout the staging operation is considered as optimum assembly gap. Thorough gapping assessment is performed considering all the transient time points to ensure that the gap values are set optimally. This paper is intended to describe the steps followed in assessing the anticipated interference and gap situations at various interfaces.","PeriodicalId":191970,"journal":{"name":"Volume 10C: Turbomachinery — Design Methods and CFD Modeling for Turbomachinery; Ducts, Noise, and Component Interactions","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134359508","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}