Numerical investigation of cross-flow separation in three-dimensional supersonic flows around circular cones

1998 ◽  
Vol 43 (10) ◽  
pp. 1154-1159
Author(s):  
Yu. P. Golovachov ◽  
N. V. Leont’eva
Keyword(s):  
Numerical Investigation ◽  
Flow Separation ◽  
Three Dimensional ◽  
Cross Flow ◽  
Supersonic Flows

Measurements of the Turbulence Structure in the Vicinity of a 3-D Separation

1996 ◽  
Vol 118 (2) ◽  
pp. 268-275 ◽  
Author(s):  
C. J. Chesnakas ◽  
R. L. Simpson
Keyword(s):  
Flow Separation ◽  
Three Dimensional ◽  
Cross Flow ◽  
Prolate Spheroid ◽  
Laser Doppler Velocimeter ◽  
Turbulence Structure ◽  
Separation Region ◽  
The Cross ◽  
And Diffusion ◽  
Boundary Layer Edge

The flow in the cross-flow separation region of a 6:1 prolate spheroid at 10 deg angle of attack, ReL = 4.20 × 106, was investigated using a novel, miniature, 3-D, fiber-optic Laser Doppler Velocimeter (LDV). The probe was used to measure three simultaneous, orthogonal velocity components from within the model, from approximately y+ = 7 out to the boundary layer edge. Velocity, Reynolds stress, and velocity triple product measurements are presented. These measurements are used to calculate the skin friction and to examine the convection, production, and diffusion of turbulent kinetic energy (TKE) about the three-dimensional separation. Comparisons of the measured production and diffusion of TKE in the cross-flow separation region—as well as in nonseparated regions of the flow—to the production and diffusion predicted by several models for these terms are shown.

Numerical Investigation of Passive Flow Control Using Wavy Blades in a Highly-Loaded Compressor Cascade

2018 ◽  
Author(s):  
Bo Wang ◽  
Yanhui Wu ◽  
Kai Liu
Keyword(s):  
Numerical Investigation ◽  
Flow Structure ◽  
Cross Flow ◽  
Leading Edge ◽  
Control Flow ◽  
Streamwise Vortices ◽  
Compressor Cascade ◽  
Control Effect ◽  
Suction Surface ◽  
Highly Loaded

Driven by the need to control flow separations in highly loaded compressors, a numerical investigation is carried out to study the control effect of wavy blades in a linear compressor cascade. Two types of wavy blades are studied with wavy blade-A having a sinusoidal leading edge, while wavy blade-B having pitchwise sinusoidal variation in the stacking line. The influence of wavy blades on the cascade performance is evaluated at incidences from −1° to +9°. For the wavy blade-A with suitable waviness parameters, the cascade diffusion capacity is enhanced accompanied by the loss reduction under high incidence conditions where 2D separation is the dominant flow structure on the suction surface of the unmodified blade. For well-designed wavy blade-B, the improvement of cascade performance is achieved under low incidence conditions where 3D corner separation is the dominant flow structure on the suction surface of the baseline blade. The influence of waviness parameters on the control effect is also discussed by comparing the performance of cascades with different wavy blade configurations. Detailed analysis of the predicted flow field shows that both the wavy blade-A and wavy blade-B have capacity to control flow separation in the cascade but their control mechanism are different. For wavy blade-A, the wavy leading edge results in the formation of counter-rotating streamwise vortices downstream of trough. These streamwise vortices can not only enhance momentum exchange between the outer flow and blade boundary layer, but also act as the suction surface fence to hamper the upwash of low momentum fluid driven by cross flow. For wavy blade-B, the wavy surface on the blade leads to a reduction of the cross flow upwash by influencing the spanwise distribution of the suction surface static pressure and guiding the upwash flow.

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