Unsteady flow analysis in a high work turbine stage with two three-dimensional Navier-Stokes codes

1997 ◽  
Author(s):  
C. Hah ◽  
F.-L. Tsung ◽  
J. Loellbach ◽  
C. Hah ◽  
F.-L. Tsung ◽  
...  
Keyword(s):  
Unsteady Flow ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Turbine Stage ◽  
Unsteady Flow Analysis ◽  
High Work

A 3D Unsteady Flow Analysis in a Doubly Constricted Tube

2000 ◽  
Author(s):  
B. V. Rathish Kumar ◽  
T. Yamaguchi ◽  
H. Liu ◽  
R. Himeno
Keyword(s):  
Pressure Drop ◽  
Unsteady Flow ◽  
Stokes Equations ◽  
Vortex Formation ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
In Series ◽  
3D Unsteady Flow

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.

Unsteady Flow Analysis and Vibratory Stress Predictions for a High Work Single Stage Turbine Blade

2012 ◽  
Author(s):  
Kurt Weber ◽  
Girish Modgil ◽  
Steve Gegg ◽  
Shyam Neerarambam ◽  
Moujin Zhang
Keyword(s):  
Flow Field ◽  
Strain Gauge ◽  
Flow Analysis ◽  
Forced Response ◽  
Single Stage ◽  
Turbine Stage ◽  
Rotating Blade ◽  
Gauge Data ◽  
Unsteady Flow Analysis ◽  
High Work

The flow field in High-Work Single-Stage (HWSS) turbines differs from traditional turbine flow fields. Operating at increased pressure ratios, wakes and trailing edge shocks at the exit of the vane are more likely to cause a vibratory response in the rotating blade. This flow field can produce increased excitation at harmonics that correspond to the vane passing frequency and harmonics higher than the vane passing frequency. In this paper, blade vibratory stresses in a HWSS gas turbine stage are predicted using unsteady pressures from two Rolls-Royce in-house flow codes that employ different phase lagged unsteady approaches. Hydra uses a harmonic storage approach, and the Vane/Blade Interaction (VBI) code uses a direct storage approach. Harmonic storage reduces memory requirements considerably. The predicted stress for four modes at two engine speeds are presented and are compared with rig test strain gauge data to assess and validate the predictive capability of the codes for forced response. Strain gauge data showed the need to consider harmonics higher than the fundamental vane passing frequency for the max power shaft speed and operating at the conditions. Because of this, it was a good case for validation and for comparing the two codes. Overall, it was found that, stress predictions using the Hydra flow code compare better with data. To the best of the authors’ knowledge, this paper is a first in comparing two different phase lagged unsteady approaches, in the context of forced response, to engine rig data for a High-Work Single Stage turbine.

Aerodynamic and Aeroacoustic Analyses of a Regenerative Blower

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.

scholarly journals Flow and Bed Topography in a River Confluence by Three-Dimensional Unsteady Flow Analysis

1995 ◽  
Vol 39 ◽  
pp. 435-440
Author(s):  
Shoji FUKUOKA ◽  
Munehiro IGARASHI ◽  
Tatsuya NISHIMURA ◽  
Setsuo MIYAZAKI
Keyword(s):  
Unsteady Flow ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Bed Topography ◽  
River Confluence ◽  
Unsteady Flow Analysis

Investigation of the Unsteady Rotor Aerodynamics in a Transonic Turbine Stage

2000 ◽  
Vol 123 (1) ◽  
pp. 81-89 ◽  
Author(s):  
R. De´nos ◽  
T. Arts ◽  
G. Paniagua ◽  
V. Michelassi ◽  
F. Martelli
Keyword(s):  
Experimental Data ◽  
Flow Field ◽  
Unsteady Flow ◽  
Rotational Speed ◽  
Pressure Field ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Turbine Stage ◽  
Rotor Aerodynamics ◽  
Transonic Turbine

The paper focuses on the unsteady pressure field measured around the rotor midspan profile of the VKI Brite transonic turbine stage. The understanding of the complex unsteady flow field is supported by a quasi-three-dimensional unsteady Navier–Stokes computation using a k-ω turbulence model and a modified version of the Abu-Ghannam and Shaw correlation for the onset of transition. The agreement between computational and experimental results is satisfactory. They both reveal the dominance of the vane shock in the interaction. For this reason, it is difficult to identify the influence of vane-wake ingestion in the rotor passage from the experimental data. However, the computations allow us to draw some useful conclusions in this respect. The effect of the variation of the rotational speed, the stator–rotor spacing, and the stator trailing edge coolant flow ejection is investigated and the unsteady blade force pattern is analyzed.

scholarly journals Characterization of Deterministic Correlations for a Turbine Stage: Part 2 — Unsteady Flow Analysis

1999 ◽  
Author(s):  
Fabien Bardoux ◽  
Francis Leboeuf ◽  
Cédric Dano ◽  
Clément Toussaint
Keyword(s):  
Unsteady Flow ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Leading Edge ◽  
Important Conclusion ◽  
Temporal Correlations ◽  
Order Of Magnitude ◽  
End Wall ◽  
Unsteady Flow Analysis

The first part of this paper analysed the time-averaged flow in a transonic single stage turbine. In this second part, we analyse the three-dimensional unsteady flow and temporal correlations in the rotor frame of reference. Two main conclusions are deduced from the comparison of each correlation. First, all correlations have the same order of magnitude. This is an important conclusion for models that handle the interaction between blade rows, because the temporal correlations are usually neglected. Second, these correlations occur in complementary localizations. In particular, the largest values of spatial deterministic correlations is located between the nozzle trailing edge and the rotor leading edge, as a consequence of nozzle wakes. Conversely, temporal deterministic correlations are located within the rotor blade row. We also establish that entropy accumulations in the stator wake near the end-wall regions generate high fluctuations of the rotor passage vortices. Such a phenomenon may have great repercussions on the radial loss distribution in the stage.

scholarly journals Developing Virtual Reality Visualizations for Unsteady Flow Analysis of Dinosaur Track Formation using Scientific Sketching

2019 ◽  
Vol 25 (5) ◽  
pp. 2145-2154 ◽  
Author(s):  
Johannes Novotny ◽  
Joshua Tveite ◽  
Morgan L. Turner ◽  
Stephen Gatesy ◽  
Fritz Drury ◽  
...  
Keyword(s):  
Virtual Reality ◽  
Unsteady Flow ◽  
Flow Analysis ◽  
Track Formation ◽  
Unsteady Flow Analysis

Aerodynamic Design Optimization of an Axial Flow Compressor Rotor

2002 ◽  
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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