Three-dimensional flow in a supersonic MHD generator with boundary layer separation

2000 ◽  
Vol 38 (2) ◽  
pp. 284-292
Author(s):  
G. P. Bazarov
Keyword(s):  
Boundary Layer ◽  
Three Dimensional ◽  
Boundary Layer Separation ◽  
Three Dimensional Flow ◽  
Layer Separation ◽  
Mhd Generator ◽  
Dimensional Flow

Instability in a viscous flow driven by streamwise vortices

2001 ◽  
Vol 432 ◽  
pp. 127-166 ◽  
Author(s):  
K. W. BRINCKMAN ◽  
J. D. A. WALKER
Keyword(s):  
Boundary Layer ◽  
Numerical Solutions ◽  
Three Dimensional ◽  
Wall Layer ◽  
External Flow ◽  
Three Dimensional Flow ◽  
Dimensional Flow ◽  
Wall Flow ◽  
Turbulent Wall ◽  
Near Wall

Unsteady separation processes at large finite, Reynolds number, Re, are considered, as well as the possible relation to existing descriptions of boundary-layer separation in the limit Re → ∞. The model problem is a fundamental vortex-driven three-dimensional flow, believed to be relevant to bursting near the wall in a turbulent boundary layer. Bursting is known to be associated with streamwise vortex motion, but the vortex/wall interactions that drive the near-wall flow toward breakdown have not yet been fully identified. Here, a simulation of symmetric counter-rotating vortices is used to assess the influence of sustained pumping action on the development of a viscous wall layer. The calculated solutions describe a three-dimensional flow at finite Re that is independent of the streamwise coordinate and consists of a crossflow plane motion, with a developing streamwise flow. The unsteady problem is constructed to mimic a typical cycle in turbulent wall layers and numerical solutions are obtained over a range of Re. Recirculating eddies develop rapidly in the near-wall flow, but these eddies are eventually bisected by alleyways which open up from the external flow region to the wall. At sufficiently high Re, an oscillation was found to develop in the streamwise vorticity field near the alleyways with a concurrent evolution of a local spiky behaviour in the wall shear. Above a critical value of Re, the oscillation grows rapidly in amplitude and eventually penetrates the external flow field, suggesting the onset of an unstable wall-layer breakdown. Local zones of severely retarded streamwise velocity are computed which are reminiscent of the low-speed streaks commonly observed in turbulent boundary layers. A number of other features also bear a resemblance to observed coherent structure in the turbulent wall layer.

Comparison of Experimental and Computational Shock Structure in a Transonic Compressor Rotor

1981 ◽  
Vol 103 (1) ◽  
pp. 78-88
Author(s):  
G. Haymann-Haber ◽  
W. T. Thompkins
Keyword(s):  
Boundary Layer ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Boundary Layer Separation ◽  
Shock Strength ◽  
Layer Separation ◽  
Transonic Compressor ◽  
Compressor Rotor ◽  
Pressure Peak ◽  
Rotor Losses

Measurement of passage shock strength in a transonic compressor rotor using a gas fluorescent technique revealed an unexpected variation in shock strength in the radial direction. An axisymmetric idealization would normally predict that the passage shock strength would gradually weaken when moving radially inward until disappearing at the sonic radius. However, the measurements indicated a sharp peak in strength at the nominal sonic radius. Blade boundary layer separation originating at this point accounts for about one half of the total rotor losses. A numerical computation of the three-dimensional inviscid flow, using time-marching techniques, has accurately predicted in general the radial and tangential variations in passage shock strength and in particular the sharp pressure peak at the nominal sonic radius. The overall shock strength was somewhat over-predicted, but this overprediction may be the result of boundary layer separation in the experiment. This paper presents comparisons between the optical density measurements and computational results and in addition a short analytical discussion which demonstrates that the sharp shock strength rise may occur in many transonic compressor rotors.

Three-Dimensional Flow Analysis in a Faraday-Type MHD Generator

2008 ◽  
Vol 44 (4) ◽  
pp. 1116-1123 ◽  
Author(s):  
Triwahju Hardianto ◽  
Nobuomi Sakamoto ◽  
Nobuhiro Harada
Keyword(s):  
Flow Analysis ◽  
Three Dimensional ◽  
Three Dimensional Flow ◽  
Mhd Generator ◽  
Dimensional Flow

Quantitative Density Visualization in a Transonic Compressor Rotor

1977 ◽  
Vol 99 (3) ◽  
pp. 460-475 ◽  
Author(s):  
A. H. Epstein
Keyword(s):  
Boundary Layer ◽  
Three Dimensional ◽  
Imaging Systems ◽  
Three Dimensional Flow ◽  
Transonic Compressor ◽  
Dimensional Flow ◽  
Compressor Rotor ◽  
Density Maps ◽  
Shock System ◽  
High Work

The flow in a 59-cm dia high work, transonic compressor rotor has been visualized using a fluorescent gas, 2,3, butanedione, as a tracer. The technique allows the three-dimensional flow to be imaged as a set of distinct planes. Quantitative static density maps were obtained by correcting the images for distortion and nonlinearities introduced by the illumination and imaging systems. These images and maps were used to analyze the three-dimensional nature of the blade’s boundary layer and shock system.

scholarly journals CROSSINN - a field experiment to study the three-dimensional flow structure in the Inn Valley, Austria

2020 ◽  
pp. 1-55 ◽  
Author(s):  
Bianca Adler ◽  
Alexander Gohm ◽  
Norbert Kalthoff ◽  
Nevio Babić ◽  
Ulrich Corsmeier ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Field Experiment ◽  
Flow Structure ◽  
State Of The Art ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Three Dimensional Flow ◽  
Three Dimensional Structure ◽  
Alpine Valley ◽  
Dimensional Flow

Capsule SummaryThe CROSSINN field experiment investigates the three-dimensional structure of thermally and dynamically driven flows and their impact on the boundary layer in a large Alpine valley using comprehensive state-of-the-art instrumentation.

Boundary-Layer Equations for Three-Dimensional Flow

2014 ◽  
pp. 75-97
Author(s):  
Ernst Heinrich Hirschel ◽  
Jean Cousteix ◽  
Wilhelm Kordulla
Keyword(s):  
Boundary Layer ◽  
Three Dimensional ◽  
Three Dimensional Flow ◽  
Boundary Layer Equations ◽  
Dimensional Flow
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