Dynamics of sedimentation of flexible fibers in moderate Reynolds number flows

2011 ◽  
Vol 48 (1) ◽  
pp. 125-136 ◽  
Author(s):  
Yingming Liu ◽  
Tai-Hsiung Wu ◽  
Rurng-Sheng Guo ◽  
Yi-Hsuan Lee ◽  
Dewei Qi
2018 ◽  
Vol 167 ◽  
pp. 341-358
Author(s):  
Ahmed Abdulkareem Alhasan ◽  
Ye Luo ◽  
Tai-Hsien Wu ◽  
Guowei He ◽  
Dewei Qi

AIAA Journal ◽  
2005 ◽  
Vol 43 (1) ◽  
pp. 76-86 ◽  
Author(s):  
Jo-Einar Emblemsvag ◽  
Ryuta Suzuki ◽  
Graham V. Candler

2007 ◽  
Vol 129 (12) ◽  
pp. 1540-1546 ◽  
Author(s):  
Zvi Rusak ◽  
Wallace J. Morris ◽  
Yoav Peles

The inception of leading-edge sheet cavitation on two-dimensional smooth thin hydrofoils at low to moderately high Reynolds number flows is investigated by an asymptotic approach and numerical simulations. The asymptotic theory is based on the work of Rusak (1994, “Subsonic Flow Around Leading Edge of a Thin Aerofoil With a Parabolic Nose,” Eur. J. Appl. Mech., 5, pp. 283–311) and demonstrates that the flow about a thin hydrofoil can be described in terms of an outer region, around most of the hydrofoil chord, and an inner region, around the nose, which asymptotically match each other. The flow in the outer region is dominated by the classical thin hydrofoil theory. Scaled (magnified) coordinates and a modified (smaller) Reynolds number (ReM) are used to correctly account for the nonlinear behavior and extreme velocity changes in the inner region, where both the near-stagnation and high suction areas occur. It results in a model (simplified) problem of a uniform flow past a semi-infinite smooth parabola with a far-field circulation governed by a parameter à that is related to the hydrofoil’s angle of attack, nose radius of curvature, and camber. The model parabola problem consists of a viscous flow that is solved numerically for various values of à and ReM to determine the minimum pressure coefficient and the cavitation number for the inception of leading-edge cavitation as function of the hydrofoil’s geometry, flow Reynolds number, and fluid thermodynamic properties. The predictions according to this approach show good agreement with results from available experimental data. This simplified approach provides a universal criterion to determine the onset of leading-edge (sheet) cavitation on hydrofoils with a parabolic nose in terms of the similarity parameters à and ReM and the effect of hydrofoil’s thickness ratio, nose radius of curvature, camber, and flow Reynolds number on the onset.


Author(s):  
Sinisˇa Krajnovic´ ◽  
Sasan Sarmast

The flow around a generic passenger car under the influence of crosswind was predicted using large eddy simulation (LES). The Reynolds number based on the incoming velocity the car’s length, L used was Re = 9 × 105. Yaw angles of crosswind of 10°, 20° and 30° were studied and the LES results were compared with the experimental observations and previous Reynolds averaged Naviers-Stokes (RANS) and detached eddy simulations (DES). The present LES were found to predict flows in better agreement with the experimental observations than previous RANS and DES. This shows that LES is better suited than RANS or DES for moderate Reynolds number flows around scale-model car in crosswinds which are inherently unsteady with regions of massive separations.


1994 ◽  
Vol 49 (5) ◽  
pp. 4044-4051 ◽  
Author(s):  
Victor S. L’vov ◽  
Itamar Procaccia

2009 ◽  
Vol 28 (1-3) ◽  
pp. 127-136 ◽  
Author(s):  
F. Fang ◽  
C.C. Pain ◽  
I.M. Navon ◽  
G.J. Gorman ◽  
M.D. Piggott ◽  
...  

1991 ◽  
Vol 113 (2) ◽  
pp. 190-197 ◽  
Author(s):  
M. R. Schumack ◽  
Jin-Bok Chung ◽  
W. W. Schultz ◽  
E. Kannatey-Asibu

Fluid flow under a grinding wheel is modeled using a perturbation scheme. In this initial effort to understand the flow characteristics, we concentrate on the case of a smooth wheel with slight clearance between the wheel and workpiece. The solution at lowest order is that given by standard lubrication theory. Higher-order terms correct for inertial and two-dimensional effects. Experimental and analytical pressure profiles are compared to test the validity of the model. Lubrication theory provides good agreement with low Reynolds number flows; the perturbation scheme provides reasonable agreement with moderate Reynolds number flows but fails at high Reynolds numbers. Results from experiments demonstrate that the ignored upstream and downstream conditions significantly affect the flow characteristics, implying that only a model based on the fully two- (or three-) dimensional Navier-Stokes equations will accurately predict the flow. We make one comparison between an experiment with a grinding wheel and the model incorporating a one-dimensional sinusoidal roughness term. For this case, lubrication theory surprisingly provides good agreement with experiment.


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