Three-dimensional, numerical study of boundary-layer stability

1986 ◽  
Author(s):  
J. MURDOCK
Keyword(s):  
Boundary Layer ◽  
Numerical Study ◽  
Three Dimensional ◽  
Boundary Layer Stability

Potential Flow Field Generated by Downstream Moving Bars and Propagated on a Turbine Blade at Low Reynolds Number

2011 ◽  
Author(s):  
Ve´ronique Penin ◽  
Pascale Kulisa ◽  
Franc¸ois Bario
Keyword(s):  
Boundary Layer ◽  
Large Scale ◽  
Numerical Study ◽  
Three Dimensional ◽  
Potential Effect ◽  
Navier Stokes ◽  
Turbine Cascade ◽  
Wake Interaction ◽  
Rotor Stator Interaction ◽  
The Stability

During the last few decades, the size and weight of turbo-machinery have been continuously reduced. However, by decreasing the distance between rows, rotor-stator interaction is strengthened. Two interactions now have the same magnitude: wake interaction and potential effect. Studying this effect is essential to understand rotor-stator interactions. Indeed, this phenomenon influences the whole flow, including the boundary layer of the upstream and downstream blades, ergo the stability of the flow and the efficiency of the machine. A large scale turbine cascade followed by a specially designed rotating cylinder system is used. Synchronised velocity LDA measurements on the vane profile show the flow and boundary layer behavior due to the moving bars. To help the general understanding and to corroborate our experimental results, numerical investigations are carried out with an unsteady three dimensional Navier-Stokes code. Moreover, the numerical study informs about the potential disturbance to the whole flow of the cascade.

Effect of curvature on three-dimensional boundary-layer stability

AIAA Journal ◽  
1985 ◽  
Vol 23 (9) ◽  
pp. 1362-1369 ◽  
Author(s):  
M. R. Malik ◽  
D. I. A. Poll
Keyword(s):  
Boundary Layer ◽  
Three Dimensional ◽  
Boundary Layer Stability ◽  
Dimensional Boundary

scholarly journals Injection into boundary layers: solutions beyond the classical form

2017 ◽  
Vol 822 ◽  
pp. 617-639 ◽  
Author(s):  
R. E. Hewitt ◽  
P. W. Duck ◽  
A. J. Williams
Keyword(s):  
Boundary Layer ◽  
Numerical Study ◽  
Flow Direction ◽  
Three Dimensional ◽  
Boundary Region ◽  
Navier Stokes ◽  
Injection Velocity ◽  
Finite Width ◽  
Viscous Effects ◽  
New States

This theoretical and numerical study presents three-dimensional boundary-layer solutions for laminar incompressible flow adjacent to a semi-infinite flat plate, subject to a uniform free-stream speed and injection through the plate surface. The novelty in this case arises from a fully three-dimensional formulation, which also allows for slot injection over a spanwise length scale comparable to the boundary-layer thickness. This approach retains viscous effects in both the spanwise and transverse directions, and effectively results in a parabolised Navier–Stokes system (sometimes referred to as the ‘boundary-region equations’). Any injection profile can be described in this approach, but we restrict attention to three-dimensional states driven by a finite-width slot aligned with the flow direction and self-similar in their downstream development. The classical two-dimensional states are known to only exist up to a critical (‘blow off’) injection amplitude, but the three-dimensional solutions here appear possible for any injection velocity. These new states take the form of low-speed streamwise-aligned streaks whose geometry depends on the amplitude of injection and the spanwise width of the injection slot; intriguingly, although very low wall shear is typically obtained, streamwise flow reversal is not observed, however hard the blowing. Asymptotic descriptions are provided in the limit of increasing slot width and fixed injection velocity, which allow for classification of the solutions according to two bounding injection rates.

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