Final Presentation

1. The Sound &
The Fury
experiments in fluid dynamics
by CC Chiang + Haram Kim

2. Introduction
We are interested in studying fluid dynamics of different
media, specifically aerodynamics and hydrodynamics.
By investigating flow through heated air and water, we
eventually tested our hypothesis on the positive, linear
relation between flow dissipation (α) and the size of the
flow channels (β), both open and closed.

3. I. Convection
Open-channel convective flow
In our first two experiments, we investigated aerodynamic flow of
air convected by a single heat source, a lighter, in an open-channel
environment.
The hypothesis was that a highly conductive secondary heat
source should be able to generate sufficient heat to induce
visible flow as a primary heat source (The lighter itself) would.
The secondary heat source used was a coil of copper wire.
We concluded that due to insufficient heating, the conductive
secondary heat source did not generate sufficient heat to induce
visible flow

4. I. Convection
Experiment set-up
Location: Gund Hall
Camera: ISO 400, F-stop 4.5, Shutter speed 1/2000
Materials: 5mm diameter copper wire, lighter

5. I. Convection
Schlerin images from copper wire heating 30 and 60 seconds (L - R)

6. II. Brownian Motion
Open-channel stochastic flow
Brownian motion is a staple of particle theory and frequently borrowed by
disciplines beyond the scientific, such as finance.
Defined as the random motion of particles suspended in a fluid, Brownian
motion is a different take on studying flows. We felt that it was a rewarding
departure from studying the effects of convectional currents on air flow
alone; it also afforded us the opportunity to experiment with materials
beyond the flame.
We hypothesize that the size of the particles would be inverse to the size of
the dissipation observed: The smaller the particle, the larger the
dissipation. Both photographs taken with and without the Schlerin screen
showed that the smaller the particle, the larger the dissipation.

7. II. Brownian Motion
Experiment Setup
Location: 20 Sumner Rd Project Room
Camera: ISO 400, F-stop 5, Shutter speed 1/800
Fluid: 95ºC (200ºF) water
Particles: Sweetener, Salt, Soap, and Sugar (L - R)

8. II. Brownian Motion
Detergent, sweetener, and sugar solutions (40g in 80ml water at 95ºC (L - R)

9. III. Turbulence
Closed-circuit surface flow
For our final experiment, we decided to investigate pipe flow
using a closed conduit - cardboard pipes of different
lengths, diameters, and pitches.
As these pipes do not have free surfaces, we could better
control the variations in air pressure and velocity of the
heated air as it passes through the pipes’ lengths.
Further to our primary hypothesis on the linear relationship
between the length of the pipe and the size of dissipation,
we further posit that 1) the flow observed is in fact turbulent
and not laminar, and that 2) the diameter of the pipe and the
angle of airflow are negatively correlated to the dispersion
of the resulting plumes.

10. III. Turbulence
Experiment set-up
Location: Fab Lab Project Room
Camera: ISO 400, F-stop 5, Shutter speed 1/800
Materials: 12”, 24”,36″ cardboard tube w/ 3″ diameter + 24” cardboard tube w/ 2″ diameter

11. III. Turbulence
12” length pipes of 3” diameters for 10, 20, and 30 seconds
(L - R)
24” length pipes of 3” diameter for 10, 20, and 30 seconds (L
- R)
36” length pipes of 3” diameters for 10, 20, and 30 seconds
(L - R)

12. III. Turbulence
From the photographs taken, we observed that the
smaller the diameter of the pipe, the more turbulent the
air flow. At a higher angle, the airflow’s turbulence
increases while at a lower angle, the relationship
between the angle and turbulence is less pronounced.
In both cases, unsteady vortices are clearly visible
within the plumes formed. With more precise
equipment, we could perhaps investigate the Reynolds
number, viscosity, and density of air flow
24” pipes of diameter 2” at 6º for 10, 20, and 30 seconds (L - R, T)
24” pipes of diameter 2” at 12º for 10, 20, and 30 seconds (L - R, T)
24” pipes of diameter 3” at 6º (L - R, T)
24” pipes of diameter 3” at 12º for 10, 20, and 30 seconds (L - R, T)

13. Based on the images obtained,
we concluded that there is
indeed a linear relation between
flow dissipation (α) and the size
of the flow channels (β), at a
factor of 0.8x.
We also observed a possible
case of vortex stretching due to
an increase in vorticity in the
direction of the closed-circuit
surface. This may have
contributed to the vortices
observed in our images.
Conclusion