Research of a Spatial Flow of a Low-Flow Stage of a Svd-22 Centrifugal Compressor by Computational Fluid Dynamics Methods Using Super-Computer Technologies

This paper provides the results of the study of a spatial flow in a low-flow stage of a SVD-22 centrifugal compressor of computational fluid dynamics methods using the Ansys CFX 14.0 software package. Low flow stages are used as the last stages of multistage centrifugal compressors. Such multistage compressors are widely used in boosting compressor stations for natural gas, in chemical industries. The flow features in low-flow stages require independent research. This is due to the fact that the developed techniques for designing centrifugal compressor stages are created for medium-flow and high-flow stages and do not apply to low-flow stages. Generally at manufacturing new centrifugal compressors, it is impossible to make a control measurement of the parameters of the working process inside the flow path elements. Computational fluid dynamics methods are widely used to overcome this difficulties. However verification and validation of CFD methods are necessary for accurate modeling of the workflow. All calculations were conducted on one of the SPbPU clusters. Parameters of one cluster node: AMD Opteron 280 2 cores, 8GB RAM. The calculations were conducted using 4 nodes (HP MPI Distributed Parallel startup type) with their full load by parallelizing processes on each node.

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Application of Super-Computer Technologies in the Research and Improvement of Steps and Elements of the Flow Path of the Turbocompressors

E3S Web of Conferences ◽

10.1051/e3sconf/202022001078 ◽

2020 ◽

Vol 220 ◽

pp. 01078

Author(s):

Yuri Kozhukhov ◽

Aleksey Danilishin ◽

Sergey Kartashov ◽

Lyubov Gileva ◽

Aleksey Yablokov ◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Centrifugal Compressor ◽

Flow Path ◽

Low Flow ◽

Compressor Stage ◽

Vaned Diffuser ◽

Control Measurement ◽

Multiprocessor Computer ◽

Centrifugal Compressor Stage

This paper presents the results of the study of the spatial flow in the turbocompressors elements of computational fluid dynamics methods using the Ansys CFX software package on a multiprocessor computer system. Five objects of research are considered: 1) flow path of an intermediate stage of an average-flow centrifugal compressor; 2) flow path of the low-flow centrifugal compressor stage; 3) a natural gas centrifugal compressor stage; 4) vaned diffuser of the first stage of an industrial multistage centrifugal compressor; 5) adjustable inlet stator of the first stage of an industrial turbocompressors. Generally at manufacturing new centrifugal compressors, it is impossible to make a control measurement of the parameters of the working process inside the flow path elements. Computational fluid dynamics methods are widely used to overcome this difficulties. However verification and validation of CFD methods are necessary for accurate modeling of the workflow. All calculations were performed on one of the SPbPU clusters. Parameters of one cluster: AMD Opteron 280 4 cores. The calculations were carried out with parallel running of the processors: HP MPI Distributed Parallel and HP MPI Local Parallel for different objects.

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Improving the quality of design calculations of viscous flow in low-flow centrifugal compressor stages by methods of computational fluid dynamics through reasonable application of different turbulence models

Omsk Scientific Bulletin ◽

10.25206/1813-8225-2021-176-24-30 ◽

2021 ◽

pp. 24-30

Author(s):

S. V. Kartashev ◽

◽

Yu. V. Kozhukhov ◽

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Turbulence Model ◽

Centrifugal Compressor ◽

Turbulence Models ◽

Low Flow ◽

Solution Stability ◽

Relative Width ◽

Computational Domain

The paper considers the issue of improving the quality of the numerical experiment in the calculation of viscous gas in the flowing part of a low-flow centrifugal compressor stage. The choice of turbulence model in creating a calculation model for calculations by methods of computational fluid dynamics is substantiated. As object of research is chosen low-flow stage with conditional flow coefficient Ф=0,008 and relative width at impeller outlet b2 /D2 =0,0133. The issue of qualitative modeling of friction losses in low-flow stages is of fundamental importance and is directly related to the choice of turbulence model. It is shown that the choice of low-Reynolds turbulence models in the case of unloaded and discontinuous low-flow stages can be made from the main common models (SpalartAllmaras, SST, k-ω) based on the economy of calculations, speed of convergence, solution stability and adequacy of the obtained results. For models with wall functions, the quality of the mesh model and the observance of the dimensionless distance to the wall y+ throughout the calculation domain are particularly important. For highReynolds turbulence models, at values of y+=25...50 on all friction surfaces of the computational domain in the optimal mode of operation, the grid independence of the solution for the entire gas-dynamic characteristic is ensured. It is unacceptable for y+ to fall into the transition region of 4...15 between the viscous sublayer and the region of the logarithmic velocity profile

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Investigation of the flow in a small-scale turbocharger centrifugal compressor

Proceedings of the Institution of Mechanical Engineers Part A Journal of Power and Energy ◽

10.1177/0957650916671277 ◽

2016 ◽

Vol 231 (1) ◽

pp. 3-13 ◽

Cited By ~ 1

Author(s):

Hamid R Hazby ◽

Liping Xu ◽

Michael V Casey

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Centrifugal Compressor ◽

Numerical Study ◽

Optical Measurements ◽

Small Scale ◽

Flow Features ◽

Design Speed ◽

And Performance ◽

Compressor Map

This paper presents an experimental and numerical study of the flow in a 1:1 scale, automotive turbocharger centrifugal compressor. Particle image velocimetry measurements have been carried out in the vaneless diffuser at 50% of the design speed. The challenges involved in taking optical measurements in the current small-scale compressor rig are discussed. The overall stage performance and the measured diffuser flow are compared with the results of steady-state computational fluid dynamics calculations. A good agreement between the computational fluid dynamics and the experimental results demonstrates that the numerical methods are capable of predicting the main flow features within the compressor. The synthesis of measured and predicted data is used to explain the sources of the flow and performance variations across the compressor map, and the differences in loss production between small and large compressors are highlighted.

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IMPROVING THE QUALITY OF DESIGNING LOW-FLOW STAGES OF CENTRIFUGAL COMPRESSORS DUE TO VERIFICATION AND VALIDATION OF CALCULATED CFD MODELS

Izvestiya of Samara Scientific Center of the Russian Academy of Sciences ◽

10.37313/1990-5378-2020-22-6-48-56 ◽

2020 ◽

Vol 22 (6) ◽

pp. 48-56

Author(s):

V.M. Ivanov ◽

◽

Yu.V. Kozhukhov ◽

A.M. Danylyshyn ◽

◽

...

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Numerical Model ◽

Low Flow ◽

Centrifugal Compressors ◽

Labyrinth Seals ◽

Design Quality ◽

Cfd Models ◽

Computational Fluid Dynamics Cfd

The quality of the produced centrifugal compressors largely depends on the design quality of the flow path. In order to carry out high-quality design of low-flow stages of centrifugal compressors, in this work, a numerical model of a low-flow stage is verified and validated, which are based on modern methods of computational fluid dynamics - CFD (computational fluid dynamics) as part of CALS technologies. In the numerical model of the step, clearances and labyrinth seals were modeled. The issues of using intergrid interfaces, application of turbulence and roughness models are considered. The obtained settings of the numerical model were used to validate seven model stages for the range of the optimal conditional flow rate Φopt = 0.008-0.018 at Mu = 0.785-0.804. The simulation results were compared with experimental data.

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Rotordynamic Force Prediction of Centrifugal Compressor Impellers Using Computational Fluid Dynamics

Journal of Engineering for Gas Turbines and Power ◽

10.1115/1.2900958 ◽

2010 ◽

Vol 133 (4) ◽

Cited By ~ 18

Author(s):

J. Jeffrey Moore ◽

David L. Ransom ◽

Flavia Viana

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Centrifugal Compressor ◽

Gas Turbines ◽

Fluid Dynamic ◽

Cross Coupling ◽

Centrifugal Impeller ◽

Operating Pressure ◽

Centrifugal Compressors ◽

Force Prediction

The energy industry depends on centrifugal compressors to produce, process, reinject, and transport many different gases. Centrifugal compressors use one or more impellers to impart momentum to the flowing gas and, thereby, produce an increase in pressure through diffusion. As the operating pressure in a compressor increases, the fluid-rotor interaction at the seals and impellers become more important. Also, the new generation of megascale liquefied natural gas compressors is dependent on accurate assessment of these forces. The aerodynamic forces and cross-coupled stiffness from the impellers cannot be accurately predicted with traditional methods and must be estimated with semiempirical formulations. The result of these inaccuracies is a potential for compressor designs that can experience unexpected, dangerous, and damaging instabilities and subsynchronous vibrations. The current investigation is intended to advance the state of the art to achieve an improved, physics-based method of predicted aerodynamic destabilizing cross-coupling forces on centrifugal compressor impellers using computational fluid dynamics (CFD). CFD was employed in this study to predict the impeller-fluid interaction forces, which gives rise to the aerodynamic cross coupling. The procedure utilized in this study was developed by Moore and Palazzolo (2002, “Rotordynamic Force Prediction of Centrifugal Impeller Shroud Passages Using Computational Fluid Dynamic Techniques With Combined Primary Secondary Flow Model,” ASME J. Eng. Gas Turbines Power, 123, pp. 910–918), which applied the method to liquid pump impellers. Their results showed good correlation to test data. Unfortunately, no such data exist for centrifugal compressors. Therefore, in order to validate the present model, comparisons will be made to predict the instability of an industrial centrifugal compressor. A parametric CFD study is then presented leading to a new analytical expression for predicting the cross-coupled stiffness for centrifugal impellers.

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Rotordynamic Force Prediction of Centrifugal Compressor Impellers Using Computational Fluid Dynamics

Volume 5: Turbo Expo 2007 ◽

10.1115/gt2007-28181 ◽

2007 ◽

Cited By ~ 2

Author(s):

J. Jeffrey Moore ◽

David L. Ransom ◽

Flavia Viana

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Centrifugal Compressor ◽

Cross Coupling ◽

Operating Pressure ◽

Centrifugal Compressors ◽

Computational Fluid Dynamics Cfd ◽

New Generation ◽

Semi Empirical ◽

Fluid Interaction

The energy industry depends on centrifugal compressors to produce, process, re-inject and transport many different gases. Centrifugal compressors use one or more impellers to impart momentum to the flowing gas and, thereby, produce an increase in pressure through diffusion. As the operating pressure in a compressor increases, the fluid-rotor interaction at the seals and impellers become more important. Also, the new generation of mega-scale Liquefied Natural Gas (LNG) compressors is dependent on accurate assessment of these forces. The aerodynamic forces and cross-coupled stiffness from the impellers cannot be accurately predicted with traditional methods and must be estimated with semi-empirical formulations. The result of these inaccuracies is a potential for compressor designs that can experience unexpected, dangerous, and damaging instabilities and subsynchronous vibrations. The current investigation is intended to advance the state-of-the-art to achieve an improved, physics-based method of predicted aerodynamic destabilizing cross-coupling forces on centrifugal compressor impellers using Computational Fluid Dynamics (CFD). CFD was employed in this study to predict the impeller-fluid interaction forces, which gives rise to the aerodynamic cross-coupling. The procedure utilized in this study was developed by Moore and Palazzolo [10], which applied the method to liquid pump impellers. Their results showed good correlation to test data. Unfortunately, no such data exists for centrifugal compressors. Therefore, in order to validate the present model, comparisons will be made to predict the instability of an industrial centrifugal compressor. A parametric CFD study is then presented leading to a new analytical expression for predicting the cross-coupled stiffness for centrifugal impellers.

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17. Design and Development of a Low-Flow, Energy Efficient Fume Hood Using Engineering Controls and Computational Fluid Dynamics (CFD)

10.3320/1.2759017 ◽

2006 ◽

Author(s):

S. Kotha ◽

R. Ryan ◽

D. Walters

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Energy Efficient ◽

Low Flow ◽

Fume Hood ◽

Design And Development ◽

Engineering Controls ◽

Flow Energy ◽

Computational Fluid Dynamics Cfd

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Flow and windage due to bolts on a rotating disc

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406216642260 ◽

2016 ◽

Vol 231 (15) ◽

pp. 2925-2941

Author(s):

Sulfickerali Noor Mohamed ◽

John Chew ◽

Nick Hills

Keyword(s):

Fluid Dynamics ◽

Computational Fluid Dynamics ◽

Time Dependent ◽

Navier Stokes ◽

Rotating Disc ◽

Rotating Machine ◽

Flow Features ◽

Rotor Surface ◽

Dynamics Simulations ◽

Cooling Air

The cooling air in a rotating machine is subject to windage as it passes over the rotor surface, particularly for cases where nonaxisymmetric features such as boltheads are encountered. The ability to accurately predict windage can help reduce the quantity of cooling air required, resulting in increased efficiency. Previous work has shown that the steady computational fluid dynamics solutions can give reasonable predictions for the effects of bolts on disc moment for a rotor–stator cavity with throughflow but flow velocities and disc temperature are not well predicted. Large fluctuations in velocities have been observed experimentally in some cases. Time-dependent computational fluid dynamics simulations reported here bring to light the unsteady nature of the flow. Unsteady Reynolds-averaged Navier–Stokes calculations for 120° and 360° models of the rotor–stator cavity with 9 and 18 bolts were performed in order to better understand the flow physics. Although the rotor–stator cavity with bolts is geometrically steady in the rotating frame of reference, it was found that the bolts generate unsteadiness which creates time-dependent rotating flow features within the cavity. At low throughflow conditions, the unsteady flow significantly increases the average disc temperature.

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