DES and RANS of Unsteady Free-Surface Wave Induced Separation

2004 ◽  
Author(s):  
Tao Xing ◽  
Mani Kandasamy ◽  
Robert Wilson ◽  
Fred Stern
Keyword(s):  
Free Surface ◽  
Surface Wave ◽  
Free Surface Wave ◽  
Wave Induced

Free-Surface Wave-Induced Separation

1996 ◽  
Vol 118 (3) ◽  
pp. 546-554 ◽  
Author(s):  
Z. J. Zhang ◽  
F. Stern
Keyword(s):  
Fluid Dynamics ◽  
Free Surface ◽  
Surface Wave ◽  
Navier Stokes ◽  
Surface Boundary ◽  
Flow Conditions ◽  
Continuity Equations ◽  
Surface Boundary Conditions ◽  
Free Surface Wave ◽  
Wave Induced

Free-surface wave-induced separation is studied for a surface-piercing NACA 0024 foil over a range of Froude numbers (0, .2, .37, .55) through computational fluid dynamics of the unsteady Reynolds-averaged Navier-Stokes and the continuity equations with the Baldwin-Lomax turbulence model, exact nonlinear kinematic and approximate dynamic free-surface boundary conditions, and a body/free-surface conforming grid. The flow conditions and uncertainty analysis are discussed. A topological rule for a surface-piercing body is derived and verified. Steady-flow results are presented and analyzed with regard to the wave and viscous flow and the nature of the separation.

Towed Underwater SPIV Measurement of Flow Fields Around a Surface-Piercing Cylinder With Free Surface Effects

2015 ◽  
Author(s):  
Jeonghwa Seo ◽  
Bumwoo Han ◽  
Shin Hyung Rhee
Keyword(s):  
Boundary Layer ◽  
Free Surface ◽  
Surface Wave ◽  
Flow Field ◽  
Cross Section ◽  
Surface Effects ◽  
Flow Fields ◽  
Two Dimensional ◽  
Two Dimensional Flow ◽  
Wave Induced

Effects of free surface on development of turbulent boundary layer and wake fields were investigated. By measuring flow field around a surface piercing cylinder in various advance speed conditions in a towing tank, free surface effects were identified. A towed underwater Stereoscopic Particle Image Velocimetry (SPIV) system was used to measure the flow field under free surface. The cross section of the test model was water plane shape of the Wigley hull, of which longitudinal length and width were 1.0 m and 100 mm, respectively. With sharp bow shape and slender cross section, flow separation was not expected in two-dimensional flow. Flow fields near the free-surface and in deep location that two-dimensional flow field was expected were measured and compared to identify free-surface effects. Some planes perpendicular to longitudinal direction near the model surface and behind the model were selected to track development of turbulent boundary layer. Froude numbers of the test conditions were from 0.126 to 0.40 and corresponding Reynolds numbers were from 395,000 to 1,250,000. In the lowest Froude number condition, free-surface wave was hardly observed and only free surface effects without surface wave could be identified while violent free-surface behavior due to wave-induced separation dominated the flow fields in the highest Froude number condition. From the instantaneous velocity fields, Time-mean velocity, turbulence kinetic energy, and flow structure derived by proper orthogonal decomposition (POD) were analyzed. As the free-surface effect, development of retarded wake, free-surface waves, and wave-induced separation were mainly observed.

Characteristics of free-surface wave on high-speed liquid lithium jet for IFMIF

2011 ◽  
Vol 417 (1-3) ◽  
pp. 1303-1306 ◽  
Author(s):  
Takuji Kanemura ◽  
Sachiko Yoshihashi-Suzuki ◽  
Hiroo Kondo ◽  
Hirokazu Sugiura ◽  
Nobuo Yamaoka ◽  
...  
Keyword(s):  
Free Surface ◽  
Surface Wave ◽  
High Speed ◽  
Liquid Lithium ◽  
Free Surface Wave
Sign in / Sign up

Export Citation Format

Share Document