Numerical predictions of the power balance in the positive column of a low-pressure Ba discharge

2005 ◽  
Author(s):  
J.J. Curry ◽  
G.G. Lister ◽  
J.E. Lawler
Keyword(s):  
Positive Column ◽  
Low Pressure ◽  
Power Balance ◽  
Numerical Predictions

Modeling the Hg-Ar low-pressure-discharge positive column: A comparative study

1992 ◽  
Vol 45 (2) ◽  
pp. 1135-1148 ◽  
Author(s):  
G. Zissis ◽  
P. Bénétruy ◽  
I. Bernat
Keyword(s):  
Comparative Study ◽  
Positive Column ◽  
Low Pressure ◽  
Pressure Discharge

Elongated dust clouds in a uniform DC positive column of low pressure gas discharge

2016 ◽  
Vol 25 (3) ◽  
pp. 035009 ◽  
Author(s):  
A D Usachev ◽  
A V Zobnin ◽  
O F Petrov ◽  
V E Fortov ◽  
M H Thoma ◽  
...  
Keyword(s):  
Positive Column ◽  
Low Pressure ◽  
Gas Discharge ◽  
Dust Clouds

The Effect of Wake Passing on a Flow Separation in a Low-Pressure Turbine Cascade

2004 ◽  
Vol 126 (2) ◽  
pp. 250-256 ◽  
Author(s):  
Michael J. Brear ◽  
Howard P. Hodson
Keyword(s):  
Separation Bubble ◽  
Phase Locking ◽  
Experimental Studies ◽  
Leading Edge ◽  
Low Pressure ◽  
Pressure Surface ◽  
Low Pressure Turbine ◽  
Numerical Predictions ◽  
Unsteady Interaction ◽  
Wake Passing

This paper describes an investigation into the effect that passing wakes have on a separation bubble that exists on the pressure surface and near the leading edge of a low-pressure turbine blade. Previous experimental studies have shown that the behavior of this separation is strongly incidence dependent and that it responds to its disturbance environment. The results presented in this paper examine the effect of wake passing in greater detail. Two-dimensional, Reynolds averaged, numerical predictions are first used to examine qualitatively the unsteady interaction between the wakes and the separation bubble. The separation is predicted to consist of spanwise vortices whose development is in phase with the wake passing. However, comparison with experiments shows that the numerical predictions exaggerate the coherence of these vortices and also overpredict the time-averaged length of the separation. Nonetheless, experiments strongly suggest that the predicted phase locking of the vortices in the separation onto the wake passing is physical.

Experimental and Numerical Investigation of Secondary Flow Structures in an Annular Low Pressure Turbine Cascade Under Periodic Wake Impact—Part 2: Numerical Results

2019 ◽  
Vol 141 (2) ◽  
Author(s):  
Benjamin Winhart ◽  
Martin Sinkwitz ◽  
Andreas Schramm ◽  
David Engelmann ◽  
Francesca di Mare ◽  
...  
Keyword(s):  
Secondary Flow ◽  
Direct Interaction ◽  
Numerical Data ◽  
Horseshoe Vortex ◽  
Low Pressure ◽  
Navier Stokes ◽  
Flow Structures ◽  
Pressure Loss Coefficient ◽  
Low Pressure Turbine ◽  
Numerical Predictions

In this work, we present the results of the numerical investigations of periodic wake–secondary flow interaction carried out on a low pressure turbine (LPT) equipped with modified T106-profile blades. The numerical predictions obtained by means of unsteady Reynolds-averaged Navier–Stokes (URANS) simulations using a k-ω-model have been compared with measurements conducted in the same configuration and showed a good agreement. Based on the verified numerical data, the Q-criterion has been employed to characterize the secondary flow structures and accurately identify their origin. An analysis of the fundamental wake kinematics and the unsteady vortex migration revealed dominant interaction mechanisms such as the circumferential fluctuation of the pressure side horseshoe vortex (HSV) and its direct interaction with the passage vortex (PV) and the concentrated shed vortex (CSV). Finally, a correlation with the total pressure loss coefficient is provided and a link to the incoming wake structures is given.

Sign in / Sign up

Export Citation Format

Share Document