Comparison of Two Three-Dimensional Unsteady Navier-Stokes Codes Applied to a Turbine Stage Flow Analysis.

Abstract Unsteady flow dynamics in a doubly constricted vessel is analyzed by using a time accurate Finite Volume solution of three dimensional incompressible Navier-Stokes equations. Computational experiments are carried out for various values of Reynolds number in order to assess the criticality of multiple mild constrictions in series and also to bring out the subtle 3D features like vortex formation. Studies reveal that pressure drop across a series of mild constrictions can get physiologically critical. Further this pressure drop is found to be sensitive to the spacing between the constrictions and also to the oscillatory nature of the inflow profile.

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Aerodynamic Design Optimization of an Axial Flow Compressor Rotor

Volume 5: Turbo Expo 2002, Parts A and B ◽

10.1115/gt2002-30445 ◽

2002 ◽

Cited By ~ 13

Author(s):

Chan-Sol Ahn ◽

Kwang-Yong Kim

Keyword(s):

Design Optimization ◽

Response Surface ◽

Computing Time ◽

Flow Analysis ◽

Three Dimensional ◽

Axial Flow ◽

Navier Stokes ◽

Transonic Compressor ◽

Compressor Rotor ◽

Design Variables

Design optimization of a transonic compressor rotor (NASA rotor 37) using the response surface method and three-dimensional Navier-Stokes analysis has been carried out in this work. The Baldwin-Lomax turbulence model was used in the flow analysis. Three design variables were selected to optimize the stacking line of the blade. Data points for response evaluations were selected by D-optimal design, and linear programming method was used for the optimization on the response surface. As a main result of the optimization, adiabatic efficiency was successfully improved. It was found that the optimization process provides reliable design of a turbomachinery blade with reasonable computing time.

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Aerodynamic and Aeroacoustic Analyses of a Regenerative Blower

Volume 1: Aircraft Engine; Fans and Blowers; Marine ◽

10.1115/gt2015-42050 ◽

2015 ◽

Author(s):

Man-Woong Heo ◽

Tae-Wan Seo ◽

Chung-Suk Lee ◽

Kwang-Yong Kim

Keyword(s):

Shear Stress ◽

Variational Formulation ◽

Stokes Equations ◽

Flow Analysis ◽

Three Dimensional ◽

Navier Stokes ◽

Side Channel ◽

Leakage Flow ◽

Navier Stokes Equations ◽

Unsteady Flow Analysis

This paper presents a parametric study to investigate the aerodynamic and aeroacoustic characteristics of a side channel regenerative blower. Flow analysis in the side channel blower was carried out by solving three-dimensional steady and unsteady Reynolds-averaged Navier-Stokes equations with the shear stress transport turbulence closure. Aeroacoustic analysis was conducted by solving the variational formulation of Lighthill’s analogy on the basis of the aerodynamic sources extracted from the unsteady flow analysis. The height and width of the blade and the angle between inlet and outlet ports were selected as three geometric parameters, and their effects on the aerodynamic and aeroacoustic performances of the blower have been investigated. The results showed that the aerodynamic and aeroacoustic performances were enhanced by decreasing height and width of blade. It was found that angle between inlet and outlet ports significantly influences the aerodynamic and aeroacoustic performances of the blower due to the stripper leakage flow.

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Centrifugal Compressor Impeller Aerodynamics: An Experimental Investigation

Volume 1: Turbomachinery ◽

10.1115/90-gt-128 ◽

1990 ◽

Author(s):

H. David Joslyn ◽

Joost J. Brasz ◽

Robert P. Dring

Keyword(s):

Flow Visualization ◽

Centrifugal Compressor ◽

Flow Analysis ◽

Three Dimensional ◽

Companion Paper ◽

Surface Flow ◽

Navier Stokes ◽

Pressure Distributions ◽

Compressor Impeller ◽

Surface Flow Visualization

The ability to acquire blade loadings (surface pressure distributions) and surface flow visualization on an unshrouded centrifugal compressor impeller is demonstrated. Circumferential and streamwise static pressure distributions acquired on the stationary shroud are also presented. Data was acquired in a new facility designed for centrifugal compressor aerodynamic research. Blade loadings calculated with a blade–to–blade potential flow analysis are compared with the measured results. Surface flow visualization reveals some complex aspects of the flow on the surface of the impeller blading and hub. In a companion paper, Dorney and Davis (1990), a state–of–the–art, three–dimensional, time–accurate, Navier Stokes prediction of the flow through the impeller is presented.

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Numerical Flow Analysis in a Subsonic Vaned Radial Diffuser With Leading Edge Redesign

Journal of Turbomachinery ◽

10.1115/1.2841219 ◽

1999 ◽

Vol 121 (1) ◽

pp. 119-126 ◽

Cited By ~ 8

Author(s):

E. Casartelli ◽

A. P. Saxer ◽

G. Gyarmathy

Keyword(s):

Static Pressure ◽

Flow Analysis ◽

Three Dimensional ◽

Pressure Rise ◽

Leading Edge ◽

Inverse Design ◽

Navier Stokes ◽

Two Dimensional ◽

Characteristic Lines ◽

Design Software

The flow field in a subsonic vaned radial diffuser of a single-stage centrifugal compressor is numerically investigated using a three-dimensional Navier–Stokes solver (TASCflow) and a two-dimensional analysis and inverse-design software package (MISES). The vane geometry is modified in the leading edge area (two-dimensional blade shaping) using MISES, without changing the diffuser throughflow characteristics. An analysis of the two-dimensional and three-dimensional effects of two redesigns on the flow in each of the diffuser subcomponents is performed in terms of static pressure recovery, total pressure loss production, and secondary flow reduction. The computed characteristic lines are compared with measurements, which confirm the improvement obtained by the leading edge redesign in terms of increased pressure rise and operating range.

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A Simulation of the Unsteady Interaction of a Centrifugal Impeller With its Vaned Diffuser: Flows Analysis

Volume 1: Turbomachinery ◽

10.1115/94-gt-105 ◽

1994 ◽

Cited By ~ 8

Author(s):

W. N. Dawes

Keyword(s):

Flow Analysis ◽

Three Dimensional ◽

Navier Stokes ◽

Centrifugal Impeller ◽

Vaned Diffuser ◽

Time Resolved ◽

High Loss ◽

Swirl Angle ◽

Unsteady Interaction ◽

Unsteady Effects

The aim of this paper is to help advance our understanding of the complex, three-dimensional, unsteady flow associated with the interaction of a splattered centrifugal impeller and its vaned diffuser. A time-resolved simulation is presented of the Krain stage performed using a time-accurate, 3D, unstructured mesh, solution-adaptive Navier-Stokes solver. The predicted flowfield, compared with experiment where available, displays a complex, unsteady interaction especially in the neighbourhood of the diffuser entry zone which experiences large periodic flow unsteadiness. Downstream of the throat, although the magnitude of this unsteadiness diminishes rapidly, the flow has a highly distorted three-dimensional character. The loss levels in the diffuser are then investigated to try and determine how time-mean loss levels compare with the levels expected from “equivalent” steady flow analysis performed by using the circumferentially averaged exit flow from the impeller as inlet to the diffuser. It is concluded that little loss could be attributed directly to unsteady effects but rather that the principle cause of the rather high loss levels observed in the diffuser is the strong spanwise distortion in swirl angle at inlet which initiates a strong hub/comer stall.

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Hypersonic Flow Analysis of Re-entry Vehicles Using Three Dimensional Navier-Stokes Equations

13th International Energy Conversion Engineering Conference ◽

10.2514/6.2015-3881 ◽

2015 ◽

Author(s):

Muharrem Ozgun ◽

Sinan Eyi

Keyword(s):

Hypersonic Flow ◽

Stokes Equations ◽

Flow Analysis ◽

Three Dimensional ◽

Navier Stokes ◽

Navier Stokes Equations

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Aerothermodynamic Effects and Modeling of the Tangential Curvature of Guide Vanes in an Axial Turbine Stage

International Journal of Rotating Machinery ◽

10.1155/2017/3806356 ◽

2017 ◽

Vol 2017 ◽

pp. 1-16

Author(s):

Tzong-Hann Shieh

Keyword(s):

Stokes Equations ◽

Three Dimensional ◽

Suction Side ◽

Meridional Flow ◽

Navier Stokes ◽

Obtuse Angle ◽

Turbine Stage ◽

Navier Stokes Equations ◽

Axial Turbine ◽

Guide Vanes

By tangential curvature of the stacking line of the profiles guide vanes can be designed, which have on both ends an obtuse angle between suction side and sidewall. This configuration, according to literature, is capable of reducing secondary loss. This type of vanes develops considerable radial components of the blade force and effects a displacement of the meridional flow towards both sidewalls. In this paper we work with a finite-volume-code for computations of the three-dimensional Reynolds averaged Navier-Stokes equations for an axial turbine stage with radial and two types of tangentially curved guide vanes. With computational results, mathematical formulations are developed for a new flow model of deflection of such blades that are formally compatible with the assumption of a rotation-symmetrical flow and with the existing throughflow codes, in order to predict the deflection angle over the blade height for the tangential leaned and curved blades.

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Calculation and Correlation of the Unsteady Flowfield in a High Pressure Turbine

Volume 4: Turbo Expo 2002, Parts A and B ◽

10.1115/gt2002-30322 ◽

2002 ◽

Cited By ~ 5

Author(s):

Milind A. Bakhle ◽

Jong S. Liu ◽

Josef Panovsky ◽

Theo G. Keith ◽

Oral Mehmed

Keyword(s):

High Pressure ◽

Three Dimensional ◽

Unsteady Aerodynamics ◽

Forced Vibrations ◽

Forced Response ◽

Operating Conditions ◽

Test Facility ◽

Navier Stokes ◽

Turbine Stage ◽

High Pressure Turbine

Forced vibrations in turbomachinery components can cause blades to crack or fail due to high-cycle fatigue. Such forced response problems will become more pronounced in newer engines with higher pressure ratios and smaller axial gap between blade rows. An accurate numerical prediction of the unsteady aerodynamics phenomena that cause resonant forced vibrations is increasingly important to designers. Validation of the computational fluid dynamics (CFD) codes used to model the unsteady aerodynamic excitations is necessary before these codes can be used with confidence. Recently published benchmark data, including unsteady pressures and vibratory strains, for a high-pressure turbine stage makes such code validation possible. In the present work, a three dimensional, unsteady, multi blade-row, Reynolds-Averaged Navier Stokes code is applied to a turbine stage that was recently tested in a short duration test facility. Two configurations with three operating conditions corresponding to modes 2, 3, and 4 crossings on the Campbell diagram are analyzed. Unsteady pressures on the rotor surface are compared with data.

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