Hydrogen bubble flow visualization of a self-oscillating cylinder vortex street “void”

2005 ◽  
Vol 17 (9) ◽  
pp. 091104 ◽  
Author(s):  
Stuart Gilbert ◽  
Lorenz Sigurdson
Keyword(s):  
Flow Visualization ◽  
Vortex Street ◽  
Bubble Flow ◽  
Hydrogen Bubble ◽  
Oscillating Cylinder

An extended use of the hydrogen bubble flow visualization method

AIAA Journal ◽  
1965 ◽  
Vol 3 (6) ◽  
pp. 1203-1203 ◽  
Author(s):  
WILLIAM O. CRIMINALE ◽  
R. W. NOWELL
Keyword(s):  
Flow Visualization ◽  
Bubble Flow ◽  
Visualization Method ◽  
Hydrogen Bubble

Hydrogen bubble flow visualization at low Reynolds numbers.

AIAA Journal ◽  
1969 ◽  
Vol 7 (8) ◽  
pp. 1635-1637 ◽  
Author(s):  
FREDERICK W. ROOS ◽  
WILLIAM W. WILLMARTH
Keyword(s):  
Flow Visualization ◽  
Reynolds Numbers ◽  
Bubble Flow ◽  
Hydrogen Bubble ◽  
Low Reynolds Numbers ◽  
Low Reynolds

Unsteady Flow Phenomena in Rotating Centrifugal Impeller Passages

1970 ◽  
Vol 92 (1) ◽  
pp. 65-71 ◽  
Author(s):  
E. Lennemann ◽  
J. H. G. Howard
Keyword(s):  
Unsteady Flow ◽  
Secondary Flow ◽  
Centrifugal Impeller ◽  
Bubble Flow ◽  
Hydrogen Bubble ◽  
Visualization Technique ◽  
Rotating Systems ◽  
Flow Phenomena ◽  
Relative Flow ◽  
Zero Flow

The phenomena of unsteady relative flow observed in a centrifugal impeller passage running at part capacity and zero flow are discussed. The mechanisms of passage stall for a shrouded and unshrouded impeller are investigated and a qualitative correlation is developed for the influence of secondary flow and inducer flow on the passage stall. The hydrogen bubble flow visualization technique is extended to higher velocities and rotating systems and provides the method for obtaining the experimental results.

scholarly journals Channel Flow Visualization by Hydrogen Bubble Methods

1971 ◽  
Vol 37 (294) ◽  
pp. 305-312 ◽  
Author(s):  
Yoshizo OKAMOTO ◽  
Juichi HANAWA ◽  
Toshiyuki KAMEOKA
Keyword(s):  
Flow Visualization ◽  
Channel Flow ◽  
Hydrogen Bubble

Effect of Channel Inlet Blockage on the Wake Structure of a Rotationally Oscillating Cylinder

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
S. Kumar
Keyword(s):  
Mode Shape ◽  
Channel Wall ◽  
Shape Change ◽  
Vortex Street ◽  
Channel Width ◽  
Channel Inlet ◽  
Oscillating Cylinder ◽  
Wake Structure ◽  
Freestream Velocity ◽  
Cylinder Diameter

This paper investigates, experimentally for the first time, the effect of channel inlet blockage induced by bringing the channel inlet walls closer together on the wake structure of a rotationally oscillating cylinder. The cylinder is placed symmetrically inside the channel inlet. The Reynolds number (based on constant upstream channel inlet freestream velocity) is 185, and three channel wall spacings of two, four, and eight cylinder diameters are used. Cylinder oscillation amplitudes vary from π/8 to π, and normalized forcing frequencies vary from 0 to 5. The diagnostics is done using hydrogen-bubble flow visualization, hot-wire anemometry, and particle image velocimetry (PIV). It is found that rotational oscillations induce inverted-vortex-street formation at channel width of two cylinder diameter where there is no shedding in unforced case. The channel wall boundary layers at this spacing undergo vortex-induced instability due to vortex shedding from cylinders and influence the mechanism of inverted-vortex-street formation near the cylinder. At channel width of four cylinder diameter, the inverted-vortex-street is still present but the mode shape change seen at normalized forcing frequency of 1.0 in the absence of channel walls is delayed due to the presence of nearby walls. The wake structure is observed to resemble the wake structure in unbounded domain case at channel width of eight cylinder diameter with some effect of channel walls on forcing parameters where mode shape change occurs. The lock-on diagram is influenced by the closeness of the channel walls, with low-frequency boundary moving to lower frequencies at smallest channel width.

Vortex street impinging upon an elliptical leading edge

1990 ◽  
Vol 211 ◽  
pp. 211-242 ◽  
Author(s):  
Ismet Gursul ◽  
Donald Rockwell
Keyword(s):  
Velocity Field ◽  
Flow Visualization ◽  
Pressure Field ◽  
Leading Edge ◽  
Vortex Street ◽  
Transverse Displacement ◽  
Vorticity Field ◽  
Measured Velocity ◽  
Vortical Structures ◽  
Pressure Fields

The interaction of a Kármán vortex street with an elliptical edge is investigated experimentally. Basic types of interaction, as a function of scale and transverse displacement of the incident vortex street, are revealed using flow visualization. Unsteady pressure fields induced by these interactions are measured by a phase-averaging technique and correlated with the visualized flow patterns for basic classes of interactions.For a generic vortex–edge interaction, measurements of the phase-averaged velocity field allow construction of streamlines and vorticity contours showing the details of the interaction, including distortion of the vortical structures near the edge. The pressure field is calculated from the measured velocity field and interpreted in relation to the vortical structures.Simulation of flow visualization using the measured velocity field demonstrates possible misinterpretations related to the underlying vorticity field.

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