Investigating the Effect of the Axial Clearance Magnitude Between the Covering Disc of the Runner and the Centrifugal Compressor Body on the Gas Dynamics in a Low-Discharge Stage Prototype

2020 ◽  
pp. 106-120
Author(s):  
A.M. Yablokov ◽  
R.A. Shtanichev ◽  
N.I. Sadovskiy ◽  
Yu.V. Kozhukhov
Keyword(s):  
Experimental Data ◽  
Centrifugal Compressor ◽  
Gas Dynamics ◽  
Software Package ◽  
Gas Flow ◽  
Compressor Stage ◽  
Peter The Great ◽  
Mesh Independence ◽  
Ansys Cfx ◽  
Axial Clearance

The paper presents the results of numerically investigating viscous gas flow in a simulated low-discharge stage of a super high-pressure type compressor, using the ANSYS CFX software package. We studied the low-discharge centrifugal compressor stage prototype designed and tested at the Compressor, Vacuum and Refrigerating Technology Department of Peter the Great St. Petersburg Polytechnic University. In order to conduct the numerical experiment, we performed a mesh independence study. We compared the properties obtained in the numerical investigation to the experimental data. In our mathematical simulation the magnitude of the axial clearance between the covering disc of the runner and the compressor body varies in the range of 1--5.5 mm; we estimate the effect that varying this number has on the loss complex characteristic 1 + βfriction + βleakage

scholarly journals Numerical Modeling of the Flow in a Vaneless Diffuser of Centrifugal Compressor Stage

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Mykola Kalinkevych ◽  
Oleg Shcherbakov
Keyword(s):  
Experimental Data ◽  
Numerical Modeling ◽  
Centrifugal Compressor ◽  
Compressor Stage ◽  
Vaneless Diffuser ◽  
Flow Core ◽  
Flow Area ◽  
Centrifugal Compressor Stage ◽  
Ansys Cfx ◽  
Sst Turbulence Model

This paper presents the results of numerical investigation of the flow in a vaneless diffuser of centrifugal compressor stage. Simulations were performed using both a commercial CFD package ANSYS CFX and the own-designed computer program. Steady conditions involving SST turbulence model were used for the calculations using CFX. To consider the interaction between impeller and diffuser, not just a diffuser but the whole stage was calculated. The own-designed methodology is based on solving of conservation equations with assumptions that flow in a diffuser is steady state and axisymmetric. The flow area is divided into the flow core and boundary layers. Results of calculation were compared with experimental data.

Numerical Investigation of the Effect of Diffuser and Volute Design Parameters on the Performance of a Centrifugal Compressor Stage

2016 ◽  
Author(s):  
Lei Yu ◽  
William T. Cousins ◽  
Feng Shen ◽  
Georgi Kalitzin ◽  
Vishnu Sishtla ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Gas Flow ◽  
Pressure Rise ◽  
Design Parameters ◽  
Compressor Stage ◽  
Flow Distortion ◽  
Cross Sectional ◽  
Centrifugal Stage ◽  
And Performance ◽  
The Impact

In this effort, 3D CFD simulations are carried out for real gas flow in a refrigeration centrifugal compressor. Both commercial and the in-house CFD codes are used for steady and unsteady simulations, respectively. The impact on the compressor performance with various volute designs and diffuser modifications are investigated with steady simulations and the analysis is focused on both the diffuser and the volute loss, in addition to the flow distortion at impeller exit. The influence of the tongue, scroll diffusion ratio, diffuser length, and cross sectional area distribution is examined to determine the impact on size and performance. The comparisons of total pressure loss, static pressure recovery, through flow velocity, and the secondary flow patterns for different volute designs show that the performance of the centrifugal compressor depends upon how well the scroll portion of the volute collects the flow from the impeller and achieves the required pressure rise with minimum flow losses in the overall diffusion process. Finally, the best design is selected based on compressor stage pressure rise and peak efficiency improvement. An unsteady simulation of the full wheel compressor stage was carried out to further examine the interaction of impeller, diffuser and the volute. The unsteady flow interactions are shown to have a major impact on the performance of the centrifugal stage.

Numerical Investigation of the Unsteady Flow Inside a Centrifugal Compressor Stage With Pipe Diffuser

2013 ◽  
Vol 136 (3) ◽  
Author(s):  
Daniel R. Grates ◽  
Peter Jeschke ◽  
Reinhard Niehuis
Keyword(s):  
Experimental Data ◽  
Unsteady Flow ◽  
Centrifugal Compressor ◽  
Measurement Techniques ◽  
Navier Stokes ◽  
Compressor Stage ◽  
Centrifugal Compressor Stage ◽  
Transonic Centrifugal Compressor ◽  
Computational Fluid Dynamics Cfd ◽  
The Subject

The subject of this paper is the investigation of unsteady flow inside a transonic centrifugal compressor stage with a pipe-diffuser by utilizing unsteady 3D Reynolds-averaged Navier–Stokes simulations (unsteady 3D URANS). The computational fluid dynamics (CFD) results obtained are compared with detailed experimental data gathered using various steady and unsteady measurement techniques. The basic phenomena and mechanisms of the complex and highly unsteady flow inside the compressor with a pipe-diffuser are presented and analyzed in detail.

Investigation of a Centrifugal Compressor Stage With Two Volutes and the Same Impeller

2003 ◽  
Author(s):  
Yinghui Dai ◽  
Abraham Engeda ◽  
Michael Cave ◽  
Jean-Luc Di Liberti
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Centrifugal Compressor ◽  
Internal Flow ◽  
Sudden Expansion ◽  
Compressor Stage ◽  
Centrifugal Compressor Stage ◽  
Compressor Impeller ◽  
Overall Performance ◽  
Good Agreement

Volute scroll, conic diffuser and sudden expansion discharge loss account for 4–6 points of efficiency decrement in a typical centrifugal compressor stage. The flow in a volute is highly complex. It is strongly believed that understanding of the detailed flow structure in a volute will provide insights on minimizing the losses by isolating the mechanisms that contributes to entropy generation. The result will be a more efficient centrifugal compressor product for customers and users and a product at higher profitability levels for manufacturers. This paper presents the experimental and numerical investigation on the matching of two different overhung volutes to the same centrifugal compressor impeller. The experimental data were measured from flange to flange firstly, then three Kiel probes were installed on pinch position circumferentially. At the same time, a detailed numerical simulation of the performance of the two volutes has been carried out. A computational model, using the k-ε turbulence model and the wall function, has been used to predict the internal flow of the both volutes. A good agreement between experimental data and numerical simulation results is found. The overall performance of the two volutes was also discussed in detail.

Numerical Investigation of the Unsteady Flow Inside a Centrifugal Compressor Stage With Pipe Diffuser

2013 ◽  
Author(s):  
Daniel R. Grates ◽  
Peter Jeschke ◽  
Reinhard Niehuis
Keyword(s):  
Experimental Data ◽  
Unsteady Flow ◽  
Numerical Investigation ◽  
Centrifugal Compressor ◽  
Measurement Techniques ◽  
Navier Stokes ◽  
Compressor Stage ◽  
Centrifugal Compressor Stage ◽  
Transonic Centrifugal Compressor ◽  
The Subject

The subject of this paper is the investigation of unsteady flow inside a transonic centrifugal compressor stage with pipe-diffuser by utilizing unsteady 3D Navier-Stokes simulations (unsteady 3D URANS). The CFD results obtained are compared with detailed experimental data gathered using various steady and unsteady measurement techniques. The basic phenomena and mechanisms of the complex and highly unsteady flow inside the compressor with pipe-diffuser are presented and analyzed in detail.

Cavity Flow Modeling in an Industrial Centrifugal Compressor Stage at Design and Off-Design Conditions

2012 ◽  
Author(s):  
Emanuele Guidotti ◽  
Giovanni Naldi ◽  
Libero Tapinassi ◽  
Valliappan Chockalingam
Keyword(s):  
Experimental Data ◽  
Computational Model ◽  
Test Data ◽  
Centrifugal Compressor ◽  
Secondary Flows ◽  
Compressor Stage ◽  
Centrifugal Compressor Stage ◽  
Leakage Flows ◽  
Flow Features ◽  
Overall Performance

Numerical tools and test equipments used in the design and validation of modern centrifugal compressor stages need to be at the state-of-the-art. In particular, a big effort is currently made to correctly model secondary flows that play a relevant role in the accuracy of the performance prediction. This paper presents the flow analysis of a high efficiency centrifugal compressor stage using high accurate computational fluid dynamics with a particular attention to the cavity flows modeling. Experimental data were also available and used to validate the numerical results. The key experimental data coming from an advanced FRAPP (Fast Response Aerodynamic Pressure Probe) and traditional probes are presented in the study as overall performance and flow features details. Test data are in fact necessary to validate and continuously improve the numerical techniques. The geometry of the stage including full modeling of the secondary flows cavities were faithfully reproduced in the computational model. The availability of new in-house automated tools for cavity meshing allow compressor aero-designers to accurately resolve leakage flows with a reasonable increase in computational and user time. The results of the computational model were in excellent agreement with the experimental data both in terms of overall performance and main flow field structures. Also details of the flow features inside the cavities matched the test data very well. Only using high accurate geometry modeling including leakage flows was possible to capture important flow features that instead were not correctly simulated with simplified computational models.

Investigation of Efficient CFD Methods for Rotating Stall Prediction in a Centrifugal Compressor Stage

2014 ◽  
Author(s):  
Daniel DeMore ◽  
Elham Maghsoudi ◽  
Jorge Pacheco ◽  
James Sorokes ◽  
Brad Hutchinson ◽  
...  
Keyword(s):  
Centrifugal Compressor ◽  
Computational Study ◽  
Transformation Method ◽  
Rotating Stall ◽  
Computational Domain ◽  
Compressor Stage ◽  
Centrifugal Compressor Stage ◽  
Ansys Cfx ◽  
Minimum Number ◽  
Stall Cells

The Time Transformation Method in ANSYS CFX is investigated as an efficient substitution to Transient Rotor Stator (TRS) analysis for rotating stall prediction in a centrifugal compressor stage. The computational study was performed by varying the number of blade sectors to determine how the circumferential extent of the computational domain affects the accuracy of the stall prediction. The results obtained using a minimum number of blades, approximately one-quarter the full blade count, and approximately one-half the full blade count were compared to both TRS and steady simulations on the same mesh to characterize the predictive capability of each approach. It is shown that both steady and unsteady methods are able to predict the formation of stall cells, but significant qualitative and quantitative differences exist in the flowfield results. The largest mass flow rate at which rotating stall was captured and the number of stall cells were in good agreement with the experimental data.

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