Characterization of Unsteady Flow Structures Near Leading-Edge Slat: Part II: 2D Computations

2004 ◽  
Author(s):  
Mehdi Khorrami ◽  
Meelan Choudhari ◽  
Luther Jenkins
Keyword(s):  
Unsteady Flow ◽  
Leading Edge ◽  
Flow Structures

Development of the Unsteady Flow on a Turbine Rotor Platform Downstream of a Rim Seal

2004 ◽  
Author(s):  
Kirk D. Gallier ◽  
Patrick B. Lawless ◽  
Sanford Fleeter
Keyword(s):  
Flow Field ◽  
Unsteady Flow ◽  
Leading Edge ◽  
Turbine Rotor ◽  
Secondary Flows ◽  
Thermal Design ◽  
Flow Rates ◽  
Image Velocimetry ◽  
Downstream Flow

In high temperature turbines, air from disk cavities is forced through the vane-rotor seal to prevent hot gas ingress into these cavities. This emergent seal air can play a significant role in the formation of secondary flows which emanate from the hub region near the rotor blade leading edge. The formation of these structures is also dependent on the inherently unsteady flow field driven by the vane-rotor interaction. As these secondary flows play an important role in both blade performance and heat transfer, the physics that governs them is of significant interest in turbine aero and thermal design. This work investigates and characterizes the aerodynamic signature of the interaction between an emergent seal flow and the hub flow approaching the downstream rotor including the effects of vane-rotor interaction. This is accomplished by means of an experimental investigation performed on the first stage of the Purdue Research Turbine using Particle Image Velocimetry (PIV). The flow field is interrogated in the near-hub region of the intra-stage space, downstream of the first vane row. Purge air is introduced through a planar seal at two different flow rates which characterize typical high and low boundaries for the range of dimensionless seal flow rates encountered in practice. Two-dimensional (radial and axial) velocity data from four measurement planes spaced from vane pressure side to mid-passage are acquired. These data are phase-locked to rotor position. The ensemble-averaged vorticity data from each of ten rotor positions provide a characterization of the effect of the rotor potential field on the emergent seal flow. Vane wake affects on purge strength and downstream flow development are captured at each of two seal flow rates.

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.

Dynamic effects on high frequency unsteady flow structures

1990 ◽  
Author(s):  
JOHN KLINGE ◽  
SCOTT SCHRECK ◽  
MARVIN LUTTGES
Keyword(s):  
Unsteady Flow ◽  
High Frequency ◽  
Flow Structures ◽  
Dynamic Effects

Characterization of Coherent Flow Structures in a Swirl-Stabilized Spray Combustor

2021 ◽  
Author(s):  
Nicholas Rock ◽  
Scott D. Stouffer ◽  
Tyler H. Hendershott ◽  
Edwin Corporan ◽  
Paul Wrzesinski
Keyword(s):  
Flow Structures ◽  
Coherent Flow Structures

Flow criticality governs leading-edge-vortex initiation on finite wings in unsteady flow

2021 ◽  
Vol 910 ◽  
Author(s):  
Yoshikazu Hirato ◽  
Minao Shen ◽  
Ashok Gopalarathnam ◽  
Jack R. Edwards
Keyword(s):  
Unsteady Flow ◽  
Leading Edge ◽  
Leading Edge Vortex ◽  
Edge Vortex

Abstract

Helical Flow Disturbances in a Multi-Nozzle Combustor

2014 ◽  
Author(s):  
Michael Aguilar ◽  
Michael Malanoski ◽  
Gautham Adhitya ◽  
Benjamin Emerson ◽  
Vishal Acharya ◽  
...  
Keyword(s):  
Unsteady Flow ◽  
Field Measurements ◽  
Flow Fields ◽  
Helical Flow ◽  
Forced Response ◽  
Flow Structures ◽  
Response Dynamics ◽  
Flow Disturbances ◽  
Nozzle Configuration ◽  
Jet Interactions

This paper describes an experimental investigation of a transversely forced, swirl stabilized combustor. Its objective is to compare the unsteady flow structures in single and triple nozzle combustors and determine how well a single nozzle configuration emulates the characteristics of a multi-nozzle one. The experiment consists of a series of velocity field measurements captured on planes normal to the jet axis. As expected, there are differences between the single and triple-nozzle flow fields, but the differences are not large in the regions upstream of the jet merging zone. Direct comparisons of the time averaged flow fields reveal a higher degree of non-axisymmetry for the flowfields of nozzles in a multi-nozzle configuration. Azimuthal decompositions of the velocity fields show that the transverse acoustic forcing has an important influence on the dynamics, but that the single and multi-nozzle configurations have similar forced response dynamics near the dump plane. Specifically, the axial dependence of the amplitude in the highest energy axisymmetric and helical flow structures is quite similar in the two configurations. This result suggests that the hydrodynamic influence of one swirling jet on the other is minimal and, as such, that jet-jet interactions in this configuration do not have a significant influence on the unsteady flow structures.

Characterization of Shock Wave–Endwall Boundary Layer Interactions in a Transonic Compressor Rotor

1988 ◽  
Vol 110 (3) ◽  
pp. 386-392 ◽  
Author(s):  
D. C. Rabe ◽  
A. J. Wennerstrom ◽  
W. F. O’Brien
Keyword(s):  
Boundary Layer ◽  
Shock Wave ◽  
Air Force ◽  
Leading Edge ◽  
Transonic Compressor ◽  
Laser Measurements ◽  
Compressor Rotor ◽  
Boundary Layer Interaction ◽  
Air Force Base

The passage shock wave–endwall boundary layer interaction in a transonic compressor was investigated with a laser transit anemometer. The transonic compressor used in this investigation was developed by the General Electric Company under contract to the Air Force. The compressor testing was conducted in the Compressor Research Facility at Wright-Patterson Air Force Base, OH. Laser measurements were made in two blade passages at seven axial locations from 10 percent of the axial blade chord in front of the leading edge to 30 percent of the axial blade chord into the blade passage. At three of these axial locations, laser traverses were taken at different radial immersions. A total of 27 different locations were traversed circumferentially. The measurements reveal that the endwall boundary layer in this region is separated from the core flow by what appears to be a shear layer where the passage shock wave and all ordered flow seem to end abruptly.

Sign in / Sign up

Export Citation Format

Share Document