scholarly journals Verification of the CFD calculation for the centrifugal compressor medium flow model stages with the help of supercomputer

2018 ◽  
Vol 245 ◽  
pp. 09011 ◽  
Author(s):  
Lyubov Gileva ◽  
Sergey Kartashov ◽  
Anatoliy Zuev ◽  
Vyacheslav Ivanov
Keyword(s):  
Fluid Dynamics ◽  
Centrifugal Compressor ◽  
Flow Model ◽  
Problem Formulation ◽  
Compressor Stage ◽  
Experiment Data ◽  
Medium Flow ◽  
Flow Investigation ◽  
Calculation Results ◽  
Flat Pattern

The goal of this work is to develop recommendations for the calculating problem formulation of the medium flow centrifugal compressor characteristics by computational fluid dynamics methods with the assessment of the computing resources necessary costs. Calculations are made on supercomputers of SPbPU “Polytechnic” and “DeltaCluster”. The object of the research is the centrifugal compressor stage for which the flow investigation has been held in the whole passage. The calculations result comparison with the practical experiment data for the whole working characteristics are shown in this work. The leakage in the lap seals and between the disks gaps investigation work has been made. The calculation of the whole 2π flat pattern has been made and also the influence on the calculation results of the between mesh interfaces has been analyzed.

Effect of Reduced Inlet Space on a Medium Flow Coefficient Centrifugal Compressor Stage

2000 ◽  
Author(s):  
William Hohlweg ◽  
Naresh Amineni
Keyword(s):  
Centrifugal Compressor ◽  
Flow Coefficient ◽  
Radius Of Curvature ◽  
Compressor Stage ◽  
Stage Design ◽  
Centrifugal Compressor Stage ◽  
Medium Flow ◽  
Multistage Compressor ◽  
Return Channel ◽  
Reduced Space

Abstract Test versus CFD predictions are presented for a medium flow coefficient, centrifugal compressor stage with 10% shorter axial stage space. Short axial length is achieved by reducing the shroud radius of curvature of the upstream return channel inlet. Situations often occur in multistage compressor applications where either rotor dynamics on new equipment or existing casing length on revamped units necessitate shorter stage space. The effect of the reduced space on various stage performance parameters is discussed referenced to the original, full length, stage design. CFD analysis for both configurations is also presented to compare with the test results and help explain the aerodynamic source of the increased losses. The complete stage is modeled on the program CFX-TASCflow beginning with a radial inlet and continuing through the impeller, diffuser and return channel.

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

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.

NUMERICAL MODEL TO SIMULATE THE EROSION ON THE SLOPE DUE TO OVERTOPPING

2010 ◽  
Vol 13 (3) ◽  
pp. 78-87
Author(s):  
Hoai Cong Huynh
Keyword(s):  
Numerical Model ◽  
Flow Model ◽  
Bed Load ◽  
Experiment Data ◽  
Step Method ◽  
Morphological Model ◽  
Load Transport ◽  
Bed Load Transport ◽  
The Finite Difference Method ◽  
Good Agreement

The numerical model is developed consisting of a 1D flow model and the morphological model to simulate the erosion due to the water overtopping. The step method is applied to solve the water surface on the slope and the finite difference method of the modified Lax Scheme is applied for bed change equation. The Meyer-Peter and Muller formulae is used to determine the bed load transport rate. The model is calibrated and verified based on the data in experiment. It is found that the computed results and experiment data are good agreement.

Numerical Simulation of Cavitating Flow in a Francis Turbine

2008 ◽  
Author(s):  
Lingjiu Zhou ◽  
Zhengwei Wang ◽  
Yongyao Luo ◽  
Guangjie Peng
Keyword(s):  
Numerical Simulation ◽  
Transport Equation ◽  
Flow Rate ◽  
Suction Side ◽  
Cavitating Flow ◽  
Francis Turbine ◽  
Efficiency Change ◽  
Experiment Data ◽  
Calculation Results ◽  
Vapor Fraction

The 3-D unsteady Reynolds averaged Navier-tokes equations based on the pseudo-homogeneous flow theory and a vapor fraction transport-equation that accounts for non-condensable gas are solved to simulate cavitating flow in a Francis turbine. The calculation results agreed with experiment data reasonably. With the decrease of the Thoma number, the cavity first appears near the centre of the hub. At this stage the flow rate and the efficiency change little. Then the cavity near the centre of the hub grows thick and the cavities also appear on the blade suction side near outlet. With further reduce of the Thoma number the cavitation extends to the whole flow path, which causes flow rate and efficiency decrease rapidly.

An Investigation of the Stability Enhancement of a Centrifugal Compressor Stage Using a Porous Throat Diffuser

2017 ◽  
Vol 140 (1) ◽  
Author(s):  
Lee Galloway ◽  
Stephen Spence ◽  
Sung In Kim ◽  
Daniel Rusch ◽  
Klemens Vogel ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Compressor Stage ◽  
Vaned Diffuser ◽  
Flow Rates ◽  
Stall Inception ◽  
Centrifugal Compressor Stage ◽  
Operating Range ◽  
Stable Operating ◽  
The Stability ◽  
Circumferential Pressure

The stable operating range of a centrifugal compressor stage of an engine turbocharger is limited at low mass flow rates by aerodynamic instabilities which can lead to the onset of rotating stall or surge. There have been many techniques employed to increase the stable operating range of centrifugal compressor stages. The literature demonstrates that there are various possibilities for adding special treatments to the nominal diffuser vane geometry, or including injection or bleed flows to modify the diffuser flow field in order to influence diffuser stability. One such treatment is the porous throat diffuser (PTD). Although the benefits of this technique have been proven in the existing literature, a comprehensive understanding of how this technique operates is not yet available. This paper uses experimental measurements from a high pressure ratio (PR) compressor stage to acquire a sound understanding of the flow features within the vaned diffuser which affect the stability of the overall compression system and investigate the stabilizing mechanism of the porous throat diffuser. The nonuniform circumferential pressure imposed by the asymmetric volute is experimentally and numerically examined to understand if this provides a preferential location for stall inception in the diffuser. The following hypothesis is confirmed: linking of the diffuser throats via the side cavity equalizes the diffuser throat pressure, thus creating a more homogeneous circumferential pressure distribution, which delays stall inception to lower flow rates. The results of the porous throat diffuser configuration are compared to a standard vaned diffuser compressor stage in terms of overall compressor performance parameters, circumferential pressure nonuniformity at various locations through the compressor stage and diffuser subcomponent analysis. The diffuser inlet region was found to be the element most influenced by the porous throat diffuser, and the stability limit is mainly governed by this element.

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