Rotor performance predictions using a Navier-Stokes method

1998 ◽  
Author(s):  
N. Sorensen ◽  
M. Hansen
Keyword(s):  
Navier Stokes ◽  
Performance Predictions

Navier-Stokes and Comprehensive Analysis Performance Predictions of the NREL Phase VI Experiment

2003 ◽  
Author(s):  
Earl P. N. Duque ◽  
Michael D. Burklund ◽  
Wayne Johnson
Keyword(s):  
Experimental Data ◽  
Wind Turbine ◽  
Turbine Rotor ◽  
Operating Conditions ◽  
Navier Stokes ◽  
Horizontal Axis Wind Turbine ◽  
Performance Predictions ◽  
Nasa Ames Research ◽  
Nrel Phase Vi ◽  
Wind Turbine Rotor

A vortex lattice code, CAMRAD II, and a Reynolds-Averaged Navier-Stoke code, OVERFLOW-D2, were used to predict the aerodynamic performance of a two-bladed horizontal axis wind turbine. All computations were compared with experimental data that was collected at the NASA Ames Research Center 80-by 120-Foot Wind Tunnel. Computations were performed for both axial as well as yawed operating conditions. Various stall delay models and dynamics stall models were used by the CAMRAD II code. Comparisons between the experimental data and computed aerodynamic loads show that the OVERFLOW-D2 code can accurately predict the power and spanwise loading of a wind turbine rotor.

scholarly journals Off-Design Performance Prediction for Radial-Flow Impellers

1988 ◽  
Author(s):  
Shen C. Lee ◽  
Daying Chen
Keyword(s):  
Stokes Equations ◽  
Mechanical Energy ◽  
Navier Stokes ◽  
Shear Stresses ◽  
Pump Impeller ◽  
Navier Stokes Equations ◽  
Measured Velocity ◽  
Production Water ◽  
Performance Predictions ◽  
Stream Functions

A numerical method was developed to consider the two-dimensional flowfield between impeller blades of a given geometry. Solution of the laminar Navier-Stokes equations in geometry-oriented coordinates was obtained for stream functions and vorticities. Velocities and pressures were calculated to determine the output fluid-energy head. The circumferential components of the normal and shear stresses along the blade were evaluated to give the input mechanical-energy head. Performance predictions were obtained for different load conditions. Comparisons were made with the measured velocity vectors of the flowfield of an air-pump impeller and with the measured performance of a production water pump, good agreements were reached.

A Numerical Study on Performances of Centrifugal Compressor Stages With Different Radial Gaps

2000 ◽  
Author(s):  
K. Sato ◽  
L. He
Keyword(s):  
Centrifugal Compressor ◽  
Stokes Equations ◽  
Numerical Study ◽  
Axial Compressor ◽  
Navier Stokes ◽  
Centrifugal Impeller ◽  
Vaned Diffuser ◽  
Navier Stokes Equations ◽  
Performance Predictions ◽  
Radial Gap

A numerical study of 3D unsteady flows in centrifugal compressor stages solving the Navier-Stokes equations is presented. The emphasis is on the effect of the radial gap between blade rows on the aerodynamic performance. In the numerical tests, Krain’s centrifugal impeller was combined with a DCA (Double Circular Arc) type radial vaned diffuser. The compressor stages with three settings of radial gap ranging from 5 to 15 percent of the impeller trailing edge radius are configured and unsteady flow simulations are carried out to compare the time-averaged efficiencies. The performance predictions show that the efficiency is deteriorated if the radial gap between blade rows is reduced with intensified blade row interaction, which is in contradiction to the general trend for axial compressor stages. In the centrifugal compressors tested, wake chopping by diffuser vanes, which usually benefits efficiency in axial compressor stages, causes unfavourable wake compression through the diffuser passages to deteriorate the efficiency.

Multidisciplinary Optimization of a Turbocharger Radial Turbine

2012 ◽  
Author(s):  
Lasse Mueller ◽  
Zuheyr Alsalihi ◽  
Tom Verstraete
Keyword(s):  
Computational Cost ◽  
Differential Evolution Algorithm ◽  
Multidisciplinary Optimization ◽  
Moment Of Inertia ◽  
Navier Stokes ◽  
Radial Turbine ◽  
Performance Predictions ◽  
Mach Number Distribution ◽  
Artificial Neural Network Ann ◽  
The Moment

This paper presents a multidisciplinary design optimization of a turbocharger radial turbine for automotive applications with the aim to improve two major manufacturer requirements: the total-to-static efficiency and the moment of inertia of the radial turbine impeller. The search for the best design is constrained by mechanical stress limitations, by the mass flow and power, and by aerodynamic constraints related to the isentropic Mach number distribution on the rotor blade. The optimization of the radial turbine is performed with a two-level optimization algorithm developed at the von Karman Institute for Fluid Dynamics (VKI). The system makes use of a Differential Evolution algorithm, an Artificial Neural Network (ANN), and a database as a compromise between accuracy and computational cost. The ANN performance predictions are periodically validated by means of accurate steady state 3D Navier-Stokes and centrifugal stress computations. The results show that it is possible to improve the efficiency and the moment of inertia only in a few numbers of iterations while limiting the stresses to a maximum value. Based on the large number of evaluated designs during the optimization, this paper provides design recommendations of a turbocharger radial turbine at least for a good preliminary design.

Navier-Stokes and Comprehensive Analysis Performance Predictions of the NREL Phase VI Experiment

2003 ◽  
Vol 125 (4) ◽  
pp. 457-467 ◽  
Author(s):  
Earl P. N. Duque ◽  
Michael D. Burklund ◽  
Wayne Johnson
Keyword(s):  
Operating Conditions ◽  
Dynamic Stall ◽  
Navier Stokes ◽  
Horizontal Axis Wind Turbine ◽  
Wind Speeds ◽  
Performance Predictions ◽  
Delay Models ◽  
Proper Power ◽  
Nrel Phase Vi ◽  
Lifting Line

A lifting-line code, CAMRAD II, and a Reynolds-Averaged Navier-Stokes code, OVERFLOW-D, were used to predict the aerodynamic performance of a two-bladed horizontal axis wind turbine. All computations were compared with experimental data that was collected at the NASA Ames Research Center 80-by-120-foot Wind Tunnel. Lifting-line computations were performed for both axial and yawed operating conditions while the Navier-Stokes computations were performed for only the axial conditions. Various stall delay models and dynamic stall models were used by the CAMRAD II code. For axial operating conditions, the predicted rotor performance varied significantly, particularly for stalled wind speeds. The lifting-line required the use of stall delay models to obtain the proper stall behavior, yet it still has difficulty in predicting the proper power magnitude in stall. The Navier-Stokes method captures the stall behavior and gives a detailed insight into the fluid mechanics of the stall behavior.

Computational Analysis of Scroll Tongue Shapes to Compressor Performance by Using Different Turbulence Models

2007 ◽  
Author(s):  
Cheng Xu ◽  
R. S. Amano
Keyword(s):  
Turbulence Model ◽  
Stokes Equations ◽  
Turbulence Models ◽  
Equation Model ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Operating Range ◽  
Performance Predictions ◽  
Compressor Performance ◽  
Compressor Efficiency

A scroll is used to collect and transport swirling fluid produced by impeller or diffuser. Scroll or volute is one of the key components of centrifugal compressors. Design of the scroll not only impacts compressor efficiency but also influences operating range of the compressor. In this study, navier-stokes equations combined with both an zero-equation turbulence model and the k-ε turbulence model were used to simulate the flows inside a single stage compressor. Detailed flow simulations for a large cut back tongue scroll were presented and discussed. Studies showed that a large cut back rounded tongue scroll provided good operating range without dropping compressor peak efficiency dramatically. The turbulence model influences to the calculation were discussed and some suggestions for scroll flow modeling were made. The numerical results obtained using two turbulence models were compared and showed agreement reasonably well with experiments. Although the k-ε model behaves well inside the boundary layer, it was not decisively better than the zero-equation model for the performance predictions.

Multidisciplinary Optimization of a Turbocharger Radial Turbine

2012 ◽  
Vol 135 (2) ◽  
Author(s):  
Lasse Mueller ◽  
Zuheyr Alsalihi ◽  
Tom Verstraete
Keyword(s):  
Computational Cost ◽  
Differential Evolution Algorithm ◽  
Multidisciplinary Optimization ◽  
Moment Of Inertia ◽  
Navier Stokes ◽  
Radial Turbine ◽  
Performance Predictions ◽  
Mach Number Distribution ◽  
Artificial Neural Network Ann ◽  
The Moment

This paper presents a multidisciplinary design optimization of a turbocharger radial turbine for automotive applications with the aim to improve two major manufacturer requirements: the total-to-static efficiency and the moment of inertia of the radial turbine impeller. The search for the best design is constrained by mechanical stress limitations, by the mass flow and power, and by aerodynamic constraints related to the isentropic Mach number distribution on the rotor blade. The optimization of the radial turbine is performed with a two-level optimization algorithm developed at the von Karman Institute for Fluid Dynamics. The system makes use of a differential evolution algorithm, an artificial neural network (ANN), and a database as a compromise between accuracy and computational cost. The ANN performance predictions are periodically validated by means of accurate steady state 3D Navier-Stokes and centrifugal stress computations. The results show that it is possible to improve the efficiency and the moment of inertia only in a few numbers of iterations while limiting the stresses to a maximum value. Based on the large number of evaluated designs during the optimization, this paper provides design recommendations of a turbocharger radial turbine at least for a good preliminary design.

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