Background
I am investigating the aerodynamics and flight dynamics
of disc-wings such as Frisbees using on-board miniaturized
instrumentation.
In addition to filling gaps in our knowledge of rotating
disc-wing aerodynamics at high advance ratios and angles of
attack, this work is instructive in exploring sensor-vehicle
integration issues characteristic of small-scale vehicles, and
in flight trajectory reconstruction from limited sensor data.
Both of these areas are relevant to planetary entry/descent
probes (my day job - see
home page )
The hardware used to measure the flight dynamics
of the frisbee were adapted from those used to measure the swing
dynamics of small parachute-borne instrumentation packages
(see paper 'A Miniature Parachute-Probe Dynamics Test-bed'
by Dooley and Lorenz in Proc. Int. Workshop on Planetary Probe
Atmospheric Entry and Descent Trajectory Analysis and Science, Lisbon,
6-9 October 2003. ESA SP-544, pp. 267-274, 2004
pdf )
My generation 1 frisbee (see materials below) used a Parallax
Basic Stamp II microcontroller, powered by 2 CR2032 lithium
button cells, to log data from a 2-axis ADXL202 accelerometer
at around 35 samples per second in flight.
Generation 2 instrumented frisbee in flight at the
University of Arizona
Close up of generation 2 frisbee
The generation 2 frisbee incorporated a more powerful
microcontroller (Netmedia BX-24), powered by 6 1/3AAA
NiMH cells. Sensors include ADXL202 2-axis accelerometer
as before, infrared altimeter, 2 photodiode sun sensors,
a magnetometer, an experimental upper surface pressure sensor, and a
speed-of-sound anemometer.
Unpublished paper on inflight acceleration measurements
pdf )
Construction Details of the Generation 1 frisbee are published in
Nuts and Volts
) magazine, February 2004
pdf )
Article on Frisbee flight in New Scientist
magazine 19th June 2004
New Scientist )
pdf )
Ralph home page )
- see also Sarah Hummel's Frisbee aerodynamics
page )