18 Feb 2009 Corn starch/water on
an audio speaker. There is a very interesting video at this link
of oobleck dancing on an audio speaker:
Subject:University of Iowa Hydraulics
Center Films on Youtube (six films)
Introduction to the study of fluid
motion (1961, 25 minutes) http://youtu.be/EIuU9Q8CGDk
The first in a widely used series of films on fluid mechanics, produced
at IIHR under the direction of Hunter Rouse.
This introductory program, designed to orient engineering students,
shows examples of flow phenomena from a host of everyday experiences.
Empirical solutions by means of scale models are illustrated. The
significance of the Euler, Froude, Reynolds, and Mach numbers as
similitude parameters is illustrated.
Dr. Hunter Rouse served as Director of IIHR from 1944 to 1966. During
this time, he was instrumental in strengthening IIHRs fundamental
research emphasis and in developing teaching programs for hydraulic
engineers. Through his writings, research, and global travels, he
established IIHR as an internationally acclaimed innovative research
and teaching laboratory.
Fundamental Principles of flow (23 min)
Second in the series, this video departs from the essential generality
of the first by explicitly illustrating, through experi ment and
animation, the basic concepts and physical relation ships that are
involved in the analysis of fluid motion. The concepts of velocity,
acceleration, circulation, and vorticity are introduced, and the use of
integral equations of motion is demonstrated by a simple example.
Fluid Motion in a gravitational field
(24 min) http://youtu.be/-xoyLhiEOus
In this third video of the series, which proceeds from the intro
ductory and the basic material presented in the first two videos,
emphasis is laid upon the action of gravity. Principles of wave
propagation are illustrated, including aspects of gen eration,
celerity, reflection, stability, and reduction to steadiness by
relative motion. Simulation of comparable phenomena in the atmosphere
and the ocean is considered.
Characteristics of laminar and
turbulent flow (26 min) http://youtu.be/eIHVh3cIujU
The fourth video deals with the effect of viscosity. Dye, smoke,
suspended particles, and hydrogen-bubbles are used to reveal the
Various combinations of Couette and plane Poiseuille flow introduce the
principles of lubrication. Axisymmetric Poiseuille flow and development
of the flow around an elliptic cylinder are related to variation in the
Reynolds number, and the growth of the boundary layer along a flat
plate is shown.
Instability in boundary layers and pipe flow is shown to lead to
turbulence. The eddy viscosity and apparent stress are intro duced by
hotwire-anemometer indications. The processes of turbulence production,
turbulent mixing, and turbulence decay are considered.
Form, drag, lift, and propulsion (24
In the fifth video of the series, emphasis is laid upon the role of
boundary-layer separation in modifying the flow pattern and producing
longitudinal and lateral components of force on a moving body. Various
conditions of separation and methods of separation control are first
illustrated. Attention is then given to the distribution of pressure
around typical body profiles and its relation to the resulting drag.
The concept of circulation introduced in the second film is developed
to explain the forces on rotating bodies and the forced vibration of
cylin dri cal bodies. Structural failure of unstable sections is
Effects of fluid compressibility (17
The last in the six-video series makes extensive use of the analogy
between gravity and sound waves and illustrates, through laboratory
demonstrations and animation, the con cepts of wave celerity, shock
waves and surges, wave reflec tion and water hammer.
Two-dimensional waves are produced by flow past a point source at
various speeds relative to the wave celerity to illus trate the effect
of changing Mach number, and the principle is applied to flow at curved
and abrupt wall deflections. Axisymmetric and three-dimensional wave
patterns are then portrayed using color Schlieren pictures.