Numerical Analysis of the Three-Dimensional Swirling Flow in Centrifugal Compressor Volutes

1994 ◽  
Vol 116 (3) ◽  
pp. 462-468 ◽  
Author(s):  
E. Ayder ◽  
R. Van den Braembussche
Keyword(s):  
Centrifugal Compressor ◽  
Swirling Flow ◽  
Three Dimensional ◽  
Numerical Procedure ◽  
Elliptical Cross ◽  
Hexahedral Elements ◽  
Flow Mechanisms ◽  
Radial Forces ◽  
Finite Volume Approach ◽  
Euler Solver

The improvement of centrifugal compressor performance and the control of the radial forces acting on the impeller due to the circumferential variation of the static pressure caused by the volute require a good understanding of the flow mechanisms and an accurate prediction of the flow pattern inside the volute. A three-dimensional volute calculation method has been developed for this purpose. The volute is discretized by means of hexahedral elements. A cell vertex finite volume approach is used in combination with a time-marching procedure. The numerical procedure makes use of a central space discretization and a four-step Runge–Kutta time-stepping scheme. The artificial dissipation used in the solver is based on the fourth-order differences of the conservative variables. Implicit residual smoothing improves the convergence rate. The loss model implemented in the code accounts for the losses due to internal shear and friction losses on the walls. A comparison of the calculated and measured results inside a volute with elliptical cross section reveals that the modified Euler solver accurately predicts the velocity and pressure distribution inside and upstream of the volute.

scholarly journals Numerical Analysis of the 3D Swirling Flow in Centrifugal Compressor Volutes

1993 ◽  
Author(s):  
E. Ayder ◽  
R. Van den Braembussche
Keyword(s):  
Centrifugal Compressor ◽  
Swirling Flow ◽  
Numerical Procedure ◽  
Cross Sectional ◽  
Elliptical Cross ◽  
Hexahedral Elements ◽  
Flow Mechanisms ◽  
Radial Forces ◽  
Finite Volume Approach ◽  
Euler Solver

The improvement of centrifugal compressor performance and the control of the radial forces acting on the impeller due to the circumferential variation of the static pressure caused by the volute require a good understanding of the flow mechanisms and an accurate prediction of the flow pattern inside the volute. A 3D volute calculation method has been developed for this purpose. The volute is discretized by means of hexahedral elements. A cell vertex finite volume approach is used in combination with a time marching procedure. The numerical procedure makes use of a central space discretization and a four step Runge-Kutta time stepping scheme. The artificial dissipation used in the solver is based on the fourth order differences of the conservative variables. Implicit residual smoothing improves the convergence rate. The loss model implemented in the code accounts for the losses due to internal shear and friction losses on the walls. A comparison of the calculated and measured results inside a volute with elliptical cross sectional shape reveals that the modified Euler solver accurately predicts the velocity and pressure distribution inside and upstream of the volute.

Experimental and Theoretical Analysis of the Flow in a Centrifugal Compressor Volute

1993 ◽  
Vol 115 (3) ◽  
pp. 582-589 ◽  
Author(s):  
E. Ayder ◽  
R. Van den Braembussche ◽  
J. J. Brasz
Keyword(s):  
Centrifugal Compressor ◽  
Cross Sections ◽  
Swirling Flow ◽  
Three Dimensional ◽  
Elliptical Cross ◽  
Loss Model ◽  
Tangential Flow ◽  
Static Pressure Distribution ◽  
Flow Loss ◽  
Mean Streamline Analysis

Detailed measurements of the swirling flow in a centrifugal compressor volute with elliptical cross section are presented. They show important variations of the swirl and throughflow velocity, total and static pressure distribution at the different volute cross sections and at the diffuser exit. The basic mechanisms defining the complex three dimensional flow structure are clarified. The different sources of pressure loss have been investigated and used to improve the prediction capability of one-dimensional mean streamline analysis correlations. The tangential flow loss model under decelerating flow conditions and the friction loss model are confirmed. New empirical loss coefficients are proposed for the exit cone loss model and the tangential flow loss model for the case of accelerating flow in the volute.

scholarly journals Experimental and Theoretical Study of the Swirling Flow in Centrifugal Compressor Volutes

1989 ◽  
Author(s):  
R. A. Van Den Braembussche ◽  
B. M. Hände
Keyword(s):  
Centrifugal Compressor ◽  
Theoretical Study ◽  
Swirling Flow ◽  
Three Dimensional ◽  
Simplified Model ◽  
Three Dimensional Flow ◽  
Dimensional Flow

Measurements of the three-dimensional flow in a simplified model of a centrifugal compressor volute at design and off-design operation are presented.

Prediction of Unsteady Effective Wake by a Euler Solver/Vortex-Lattice Coupled Method

2003 ◽  
Vol 47 (02) ◽  
pp. 131-144
Author(s):  
Jin-Keun Choi ◽  
Spyros A. Kinnas
Keyword(s):  
Vortex Lattice ◽  
Three Dimensional ◽  
Lattice Method ◽  
Coupled Method ◽  
Vortex Lattice Method ◽  
Finite Volume Approach ◽  
Euler Solver ◽  
Effective Wake ◽  
Total Velocity ◽  
Surface Vortex

A fully three-dimensional Euler solver, based on a finite volume approach, is developed and applied to the prediction of the unsteady effective wake for propellers subject to non-axisymmetric inflows. The Euler solver is coupled with an existing lifting-surface vortex-lattice method for the computation of unsteady propeller flows. The coupled method is validated against the uniform inflow case, in which ideally the uniform flow should be recovered as the effective wake. The predicted total velocity field correlates very well with that measured in the water tunnel experiment. Lastly, the unsteady effective wake predicted by the present method is compared with the steady effective wake predicted by the authors' previous steady method.

Numerical Simulation of Impeller–Volute Interaction in Centrifugal Compressors

1999 ◽  
Vol 121 (3) ◽  
pp. 603-608 ◽  
Author(s):  
K. Hillewaert ◽  
R. A. Van den Braembussche
Keyword(s):  
Numerical Simulation ◽  
Boundary Conditions ◽  
Unsteady Flow ◽  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Numerical Procedure ◽  
Flow Calculation ◽  
Total Temperature ◽  
Temperature And Pressure ◽  
Good Agreement

A numerical procedure to predict the impeller–volute interaction in a single-stage centrifugal compressor is presented. The method couples a three-dimensional unsteady flow calculation in the impeller with a three-dimensional time-averaged flow calculation in the volute through an iterative updating of the boundary conditions on the interface of both calculation domains. The method has been used to calculate the flow in a compressor with an external volute at off-design operation. Computed circumferential variations of flow angles, total temperature, and pressure are shown and compared with measurements. The good agreement between the predictions and measurements confirms the validity of the approach.

Effects of volute’s asymmetry on the performance of a turbocharger centrifugal compressor

2016 ◽  
Vol 232 (7) ◽  
pp. 1235-1246 ◽  
Author(s):  
Xinqian Zheng ◽  
Yun Lin ◽  
Zhenzhong Sun
Keyword(s):  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Pressure Condition ◽  
Three Dimensional Flow ◽  
Outlet Pressure ◽  
Flow Mechanisms ◽  
Simulation Results ◽  
Steady Simulation ◽  
Stable Flow ◽  
Stage Efficiency

The effects of the volute’s asymmetry on the performance of a turbocharger centrifugal compressor were studied using steady simulations and theoretical analysis. According to the steady simulation results, it is found that the volute’s asymmetry has significant influence on the performance of the centrifugal compressor. The variation of the stage efficiency due to volute’s asymmetry is up to 4%. Meanwhile, the volute’s asymmetry restricts the compressor stable flow range by imposing a distorted outlet pressure condition and forcing some certain impeller passages to suffer from a worse flow than the others. These certain passages are likely to stall first and trigger the surge, as the stage flow rate further decreases. In other words, the local stall triggers the surge. The relevant flow mechanisms were given to explain the effects based on the three-dimensional flow field, and a new model was developed to demonstrate how the local stall induced by the volute’s asymmetry triggers the system instability.

Flow Studies in Canine Artery Bifurcations Using a Numerical Simulation Method

1992 ◽  
Vol 114 (4) ◽  
pp. 504-511 ◽  
Author(s):  
X. Y. Xu ◽  
M. W. Collins ◽  
C. J. H. Jones
Keyword(s):  
Newtonian Fluid ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Numerical Procedure ◽  
Simulation Method ◽  
Velocity Profiles ◽  
Navier Stokes ◽  
Element Mesh ◽  
Finite Volume Approach

Three-dimensional flows through canine femoral bifurcation models were predicted under physiological flow conditions by solving numerically the time-dependent threedimensional Navier-stokes equations. In the calculations, two models were assumed for the blood, those of (a) a Newtonian fluid, and (b) a non-Newtonian fluid obeying the power law. The blood vessel wall was assumed to be rigid this being the only approximation to the prediction model. The numerical procedure utilized a finite volume approach on a finite element mesh to discretize the equations, and the code used (ASTEC) incorporated the SIMPLE velocity-pressure algorithm in performing the calculations. The predicted velocity profiles were in good qualitative agreement with the in vivo measurements recently obtained by Jones et al. [1]. The non-Newtonian effects on the bifurcation flow field were also investigated, and no great differences in velocity profiles were observed. This indicated that the non-Newtonian characteristics of the blood might not be an important factor in determining the general flow patterns for these bifurcations, but could have local significance. Current work involves modeling wall distensibility in an empirically valid manner. Predictions accommodating these will permit a true quantitative comparison with experiment.

Experimental and Theoretical Analysis of the Flow in a Centrifugal Compressor Volute

1992 ◽  
Author(s):  
E. Ayder ◽  
R. Van den Braembussche ◽  
J. J. Brasz
Keyword(s):  
Centrifugal Compressor ◽  
Cross Sections ◽  
Swirling Flow ◽  
Elliptical Cross ◽  
Loss Model ◽  
Pressure Losses ◽  
Tangential Flow ◽  
Static Pressure Distribution ◽  
Flow Loss ◽  
Mean Streamline Analysis

Detailed measurements of the swirling flow in a centrifugal compressor volute with elliptical cross section are presented. They show important variations of the swirl- and throughflow velocity, total and static pressure distribution at the different volute cross sections and at the diffuser exit. The basic mechanisms defining the complex 3D flow structure are clarified. The different sources of pressure losses have been investigated and used to improve the prediction capability of one dimensional mean streamline analysis correlations. The tangential flow loss model, under decelerating flow conditions, and friction loss model are confirmed. New emprical loss coefficients are proposed for the exit cone loss model and the tangential flow loss model for the case of accelerating flow in the volute.

Measurements of Reynolds stresses in centrifugal compressor vaned diffusers

2008 ◽  
Vol 222 (8) ◽  
pp. 1487-1503 ◽  
Author(s):  
A Pinarbasi ◽  
K M Guleren ◽  
A Ozturk
Keyword(s):  
Centrifugal Compressor ◽  
Three Dimensional ◽  
Leading Edge ◽  
Sampling Technique ◽  
Phase Lock Loop ◽  
Reynolds Stresses ◽  
Design Strategies ◽  
Vaned Diffuser ◽  
Phase Lock ◽  
Flow Mechanisms

A phase lock loop sampling technique has been developed in order to perform detailed measurements for the flow field downstream of a turbomachinery rotor. Measurements have been carried out in the vaned diffuser of a low-speed centrifugal compressor using a triple hot wire anemometer. The phase lock loop technique employed in this work has provided a comprehensive representation of the complex three-dimensional unsteady flow in these diffusers. The diffuser vanes were found to have a significant influence on the flow in the vaneless space. The mixing out of the blade wakes is enhanced and accordingly the Reynolds stress levels drop rapidly between the impeller exit and the vane leading edge. The results provide an insight into the flow mechanisms responsible for the losses and hence can be used to develop better design strategies in the future. The flow also exhibits high levels of anisotropy, especially at the mid-vane positions. This suggests that basic Reynolds-averaged Navier—Stokes (RANS) models, including standard one- or two-equation models, might not be sufficient to accurately model the flow in centrifugal compressor diffusers.

Prediction of Non-Axisymmetric Effective Wake by a Three-Dimensional Euler Solver

2001 ◽  
Vol 45 (01) ◽  
pp. 13-33
Author(s):  
Jin-Keun Choi ◽  
Spyros A. Kinnas
Keyword(s):  
Vortex Lattice ◽  
Three Dimensional ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Actuator Disk ◽  
Finite Volume Approach ◽  
Euler Solver ◽  
Effective Wake ◽  
Total Velocity ◽  
Surface Vortex

A fully three-dimensional Euler solver, based on a finite volume approach, is developed and applied to the prediction of the effective wake for propellers subject to non-axisymmetric inflows. The method is coupled with an existing lifting-surface vortex-lattice method for the analysis of unsteady cavitating propeller flows. The results are validated against analytical solutions from actuator disk theory. The effect of the grid parameters on the results (circumferential average and amplitudes of harmonics of the predicted effective wake) is found to be very weak. The predicted total velocity field correlates very well with that measured in propeller experiments.

Sign in / Sign up

Export Citation Format

Share Document