scholarly journals Steady Streaming Motion in Entrance Region of Curved Tubes during Oscillatory Flow

2017 ◽  
Author(s):  
Masaru Sumida
Keyword(s):  
Oscillatory Flow ◽  
Entrance Region ◽  
Steady Streaming ◽  
Streaming Motion

scholarly journals Steady streaming around a cylinder pair

2016 ◽  
Vol 472 (2195) ◽  
pp. 20160522 ◽  
Author(s):  
W. Coenen
Keyword(s):  
Reynolds Number ◽  
Oscillatory Flow ◽  
Circular Cylinders ◽  
Flow Topology ◽  
Order Unity ◽  
Steady Streaming ◽  
Stokes Layer ◽  
Streaming Velocity ◽  
Gap Width ◽  
Streaming Motion

The steady streaming motion that appears around a pair of circular cylinders placed in a small-amplitude oscillatory flow is considered. Attention is focused on the case where the Stokes layer thickness at the surface of the cylinders is much smaller than the cylinder radius, and the streaming Reynolds number is of order unity or larger. In that case, the steady streaming velocity that persists at the edge of the Stokes layer can be imposed as a boundary condition to numerically solve the outer streaming motion that it drives in the bulk of the fluid. It is investigated how the gap width between the cylinders and the streaming Reynolds number affect the flow topology. The results are compared against experimental observations.

Oscillatory flow over a cylinder resting on a plane boundary

1996 ◽  
Vol 7 (6) ◽  
pp. 545-558 ◽  
Author(s):  
M. F. Wybrow ◽  
N. Riley
Keyword(s):  
Circular Cylinder ◽  
Boundary Layers ◽  
Outer Layer ◽  
Oscillatory Flow ◽  
Outer Boundary ◽  
Reynolds Numbers ◽  
Plane Boundary ◽  
Simple Experiment ◽  
Steady Streaming ◽  
Streaming Motion

Oscillatory flow over a circular cylinder, or part-cylinder, placed on a plane boundary, when the Strouhal and streaming Reynolds numbers are large, is considered. The solution is developed in matching inner and outer boundary layers. A steady streaming motion in the outer layer can lead to a net flow away from the cylinder along the plane boundary. A simple experiment substantiates this prediction, and the implications for bed-scouring are examined.

Steady streaming of fluid in the entrance region of a tube during oscillatory flow

1999 ◽  
Vol 11 (10) ◽  
pp. 2957-2962 ◽  
Author(s):  
Irwin S. Goldberg ◽  
Zongqin Zhang ◽  
Minhtan Tran
Keyword(s):  
Oscillatory Flow ◽  
Entrance Region ◽  
Steady Streaming

scholarly journals Wave-Induced Oscillatory Flow Over a Sloping Rippled Bed

Water ◽  
2019 ◽  
Vol 11 (8) ◽  
pp. 1618 ◽  
Author(s):  
Carla Faraci ◽  
Pietro Scandura ◽  
Carmelo Petrotta ◽  
Enrico Foti
Keyword(s):  
Oscillatory Flow ◽  
Thin Layers ◽  
Steady Streaming ◽  
Wave Flume ◽  
Flow Asymmetry ◽  
Horizontal Part ◽  
Cohesive Bed ◽  
Sloping Beach ◽  
Wave Induced ◽  
Rippled Bed

In this paper, the findings of an experimental analysis aimed at investigating the flow generated by waves propagating over a fixed rippled bed within a wave flume are reported. The bottom of the wave flume was constituted by horizontal part followed by a 1:10 sloping beach. Bedforms were generated in a previous campaign performed with loose sand, and then hardened by means of thin layers of concrete. The flow was acquired through a Vectrino Profiler along two different ripples, one located in the horizontal part of the bed and the second over the sloping beach. It was observed that, on the horizontal bed, near the bottom, ripple lee side triggered the appearance of an onshore directed steady streaming, whereas ripple stoss side gave rise to an offshore directed steady streaming. On the sloping bed, a strong return current appears at all positions, interacting with the rippled bottom. The turbulence is non-negligible within the investigated water depth, particularly when velocities were onshore directed, due to flow asymmetry. Turbulence caused a considerable flow stirring which, above a non-cohesive bed, could lift the sediment up in the water column and give rise to a strong sediment transport.

Unsteady flow about a sphere at low to moderate Reynolds number. Part 1. Oscillatory motion

1994 ◽  
Vol 277 ◽  
pp. 347-379 ◽  
Author(s):  
Eugene J. Chang ◽  
Martin R. Maxey
Keyword(s):  
Reynolds Number ◽  
Unsteady Flow ◽  
Steady Flow ◽  
Oscillatory Flow ◽  
Reynolds Numbers ◽  
Oscillatory Motion ◽  
Rigid Sphere ◽  
Flow Conditions ◽  
Steady Streaming ◽  
Moderate Reynolds Number

A direct numerical simulation, based on spectral methods, has been used to compute the time-dependent, axisymmetric viscous flow past a rigid sphere. An investigation has been made for oscillatory flow about a zero mean for different Reynolds numbers and frequencies. The simulation has been verified for steady flow conditions, and for unsteady flow there is excellent agreement with Stokes flow theory at very low Reynolds numbers. At moderate Reynolds numbers, around 20, there is good general agreement with available experimental data for oscillatory motion. Under steady flow conditions no separation occurs at Reynolds number below 20; however in an oscillatory flow a separation bubble forms on the decelerating portion of each cycle at Reynolds numbers well below this. As the flow accelerates again the bubble detaches and decays, while the formation of a new bubble is inhibited till the flow again decelerates. Steady streaming, observed for high frequencies, is also observed at low frequencies due to the flow separation. The contribution of the pressure to the resultant force on the sphere includes a component that is well described by the usual added-mass term even when there is separation. In a companion paper the flow characteristics for constant acceleration or deceleration are reported.

Steady streaming around a circular cylinder in an oscillatory flow

2009 ◽  
Vol 36 (14) ◽  
pp. 1089-1097 ◽  
Author(s):  
Hongwei An ◽  
Liang Cheng ◽  
Ming Zhao
Keyword(s):  
Circular Cylinder ◽  
Oscillatory Flow ◽  
Steady Streaming

Quasi-steady vortical structures in vertically vibrating soap films

1998 ◽  
Vol 372 ◽  
pp. 213-230 ◽  
Author(s):  
JOSÉ M. VEGA ◽  
F. J. HIGUERA ◽  
P. D. WEIDMAN
Keyword(s):  
Numerical Simulations ◽  
Liquid Flow ◽  
Excitation Frequency ◽  
Soap Film ◽  
Soap Films ◽  
Vortical Structures ◽  
Steady Streaming ◽  
Streaming Motion

An analysis of the quasi-steady streaming of the liquid in a vertically vibrated horizontal soap film is reported. The air around the soap film is seen to play a variety of roles: it transmits normal and tangential oscillatory stresses to the film, damps out Marangoni waves, and forces non-oscillatory deflection of the film and tangential motion of the liquid. Non-oscillatory volume forcing originating inside the liquid is also analysed. This forcing dominates the quasi-steady streaming when the excitation frequency is close to the eigenfrequency of a Marangoni mode of the soap film, while both volume forcing in the liquid and surface forcing of the gas on the liquid are important when no Marangoni mode resonates. Different manners by which the combined forcings can induce quasi-steady streaming motion are discussed and some numerical simulations of the quasi-steady liquid flow are presented.

Boundary-layer flow around a submerged circular cylinder induced by free-surface travelling waves

1996 ◽  
Vol 316 ◽  
pp. 241-257 ◽  
Author(s):  
B. Yan ◽  
N. Riley
Keyword(s):  
Free Surface ◽  
Circular Cylinder ◽  
Wave Amplitude ◽  
Perturbation Methods ◽  
Travelling Waves ◽  
Inviscid Flow ◽  
Steady Streaming ◽  
Viscous Forces ◽  
Layer Flow ◽  
Streaming Motion

We consider the fluid flow induced when free-surface travelling waves pass over a submerged circular cylinder. The wave amplitude is assumed to be small, and a suitably defined Reynolds number large, so that perturbation methods may be employed. Particular attention is focused on the steady streaming motion, which induces circulation about the cylinder. The viscous forces acting on the cylinder are calculated and compared with the pressure forces which are solely responsible for the loading on the cylinder in a purely inviscid flow.

Pulsatile Blood Flow in a Channel of Small Exponential Divergence—Part II: Steady Streaming Due to the Interaction of Viscous Effects With Convected Inertia

1976 ◽  
Vol 98 (4) ◽  
pp. 707-713 ◽  
Author(s):  
D. J. Schneck ◽  
F. J. Walburn
Keyword(s):  
Viscous Incompressible Fluid ◽  
Exponential Rate ◽  
Inertial Effects ◽  
Pulsatile Blood Flow ◽  
Viscous Effects ◽  
Flow Phenomenon ◽  
Steady Streaming ◽  
Self Consistent ◽  
Downstream Flow ◽  
Streaming Motion

This paper describes a secondary streaming motion that appears during the pulsatile flow of a viscous, incompressible fluid through rigid circular channels having walls which diverge at a slow exponential rate. Arising primarily from the interaction of viscous effects with convected inertial effects, this steady streaming motion acts to continuously retard downstream flow near the wall surface and enhance such flow nearer midstream. The secondary flow phenomenon is shown to be directly proportional to mean Reynolds Number, inversely proportional to the unsteadiness parameter of the flow, and to attenuate with decreasing rates of channel divergence. These effects are all self-consistent and interdependent.

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