Post on 07-Apr-2018
8/6/2019 Flow Visualizations
1/39
Von Karman Institute for Fluid DynamicsChausse de Waterloo, 72
B - 1640 Rhode Saint Gense - Belgium
VKI Lecture Series
"Measurement Techniques in Fluid Dynamics
an Introduction"
FLOW VISUALIZATIONS
Compiled by
M. Carbonaro
8/6/2019 Flow Visualizations
2/39
1994 by the von Karman InstituteThe pictures in the pages that follow are examples of selected Flow Visualization Techniques, all applied (with one exception) at the von
Karman Institute, by members of the Faculty, PhD researchers, Diploma Course members, and members of the Short Training Program.
With the exception mentioned, they can be freely used and diffused, provided they are kept unmodified in the original form, that the VKIorigin is duly acknowledged, and that these two conditions are imposed to any further recipient of the material.
The techniques are illustrated in the following order:
On a solid surface (limiting streamlines or skin friction lines):
Oil flow
Sublimation Sand erosion Wall tufts Oil dots Oil streaks Wall dye steaks
On a free surface (water table):
Surface bubbles Hydraulic analogy (surface waves) Hydraulic analogy (Water colors)
In a 3D space:
Tufts in air (grid, pole) Smoke in air Colored smoke (smoke wire) Laser sheet & smoke Dye in water: color streaks, or all water Hydrogen bubbles
Of potential flow (Hele-Shaw analogy)
8/6/2019 Flow Visualizations
3/39
Oil flow visualization.
Airflow around a bluff protuberance mounted on a flat plate.
(top view, flow from left)
8/6/2019 Flow Visualizations
4/39
Oil flow visualization.
Airflow around a bluff protuberance mounted on a flat plate.
(side view, airflow from left)
8/6/2019 Flow Visualizations
5/39
Oil flow visualization of flow around a house.
Top view, airflow from left.
8/6/2019 Flow Visualizations
6/39
Oil flow visualization.
Airflow on end wall of a turbine blade cascade.
8/6/2019 Flow Visualizations
7/39
Oil flow visualization.
Airflow around a missile body at incidence.
8/6/2019 Flow Visualizations
8/39
Oil flow visualization.
Airflow around a missile body at incidence.
Detail of flow near hemispherical front part of missile.
8/6/2019 Flow Visualizations
9/39
Surface flow visualization.
Incipient wing stall, showing saddle point and two focal points of vortical separation.
8/6/2019 Flow Visualizations
10/39
Sublimation technique in Mach 6 hypersonic tunnel.
Triangular fin mounted on a flat plate. Flow from left.
8/6/2019 Flow Visualizations
11/39
Sand erosion technique. Low speed visualization of urban microclimate patterns.
8/6/2019 Flow Visualizations
12/39
Wall tufts technique.
Surface flow on a turboprop aircraft engine pod.
8/6/2019 Flow Visualizations
13/39
Wall tufts technique.
Determination of stagnation point position at leading edge of an aircraft wing.
8/6/2019 Flow Visualizations
14/39
Oil dots technique. Hypersonic tunnel, Mach 15.
Visualization of velocity direction and magnitude on hypersonic delta wing.
8/6/2019 Flow Visualizations
15/39
Oil streaks technique.
Visualization of streamlines on the upswept afterbody of a transport aircraft.
8/6/2019 Flow Visualizations
16/39
Water tunnel flow visualization by wall dye streaks.
Triangular fin mounted on a flat plate. Flow from left.
8/6/2019 Flow Visualizations
17/39
Surface bubbles flow visualization.
Water table, Fr < 1, turbulent wakes behind an array of bluff obstacles.
8/6/2019 Flow Visualizations
18/39
Surface bubbles flow visualization.
Water table, Fr < 1, separated flow and vortex formations behind bluff triangular body.
8/6/2019 Flow Visualizations
19/39
Hydraulic analogy in water table, Fr > 1.
Surface waves to visualize expansions and shock waves in a supersonic intake (choked or not).
8/6/2019 Flow Visualizations
20/39
Hydraulic analogy in water table, Fr > 1.
Expansion and shock waves in a supersonic compressor cascade.
8/6/2019 Flow Visualizations
21/39
Smoke flow visualization in air.
Reversed turbulent flow across on open door in a building.
8/6/2019 Flow Visualizations
22/39
Smoke filaments flow visualization.
(copyright not belonging to VKI)
8/6/2019 Flow Visualizations
23/39
Smoke flow visualization of spoilers effectiveness in a truck to control flow separation on truck sides.
8/6/2019 Flow Visualizations
24/39
Smoke flow visualization of exhaust plume from forced draft cooling towers.
8/6/2019 Flow Visualizations
25/39
Smoke wire technique. Colored smoke to visualize horse shoe vortices on the end wall of a turbine blade cascade.
8/6/2019 Flow Visualizations
26/39
Smoke and laser sheet visualization of vortical flow on upper surface of delta wing.
8/6/2019 Flow Visualizations
27/39
Smoke and laser sheet visualization of turbulentconvection patterns.
8/6/2019 Flow Visualizations
28/39
Color streaks in water, to visualize streamlines around a bluff protuberance mounted on a flat plate.
8/6/2019 Flow Visualizations
29/39
Color streaks in water, to visualize horse shoe vortex formation upstream of a bluff protuberance mounted on a flat plate (side
view).
8/6/2019 Flow Visualizations
30/39
Color streaks in water, to visualize horse shoe vortex formation upstream of a bluff protuberance mounted on a flat plate (top
view).
8/6/2019 Flow Visualizations
31/39
Water tunnel flow visualization with color streaks. Body vortices on leeward side of missile at incidence (side view).
8/6/2019 Flow Visualizations
32/39
Water tunnel flow visualization with color streaks. Body vortices on leeward side of missile at incidence (top view).
8/6/2019 Flow Visualizations
33/39
Water tunnel flow visualization of Karman vortex street behind a cylinderat increasing Re number. Fluorescent dye, and lasersheet.
8/6/2019 Flow Visualizations
34/39
Hydrogen bubbles flow visualization in water tunnel.
Transitional boundary layer profiles on a flat plate, behind a vibrating ribbon.
8/6/2019 Flow Visualizations
35/39
Hydrogen bubbles flow visualization in a water channel.
Flow around the prongs of a scaled-up hot wire anemometer.
8/6/2019 Flow Visualizations
36/39
Hydrogen bubbles and Laser Sheet flow visualization. in a water tunnel. Co-rotating vortices and saddle points upstream of a
bluff protuberance mounted on a flat plate (flow from right).
8/6/2019 Flow Visualizations
37/39
Colored water flow visualization : fluidic bistable amplifier in a free-surface water table.
8/6/2019 Flow Visualizations
38/39
Colored water flow visualization: fluidic oscillator (jet-edge-cavity resonator) in a free-surface water table.
8/6/2019 Flow Visualizations
39/39
Hele-Shaw flow visualization of potential flow around a cylinder.