Gust Probe Thermal
Anemometer
There are two configurations
of the technology: a single or double element probe. Operation
of both is depicted below.
| Single-Element Probe |
Double-Element Probe |
 |
single
anemometer element perpendicular to airstream
element
picks up all flow perpendicular
to its major axis (cross and longitudinal) - flow
components not separated |
|
 |
double
(parallel) anemometer elements perpendicular to
airstream
double
element configuration measures longitudinal and
cross components of flow |
|
These pictures show
the relative size of the single-element gust probe anemometer
and indicate where the element resides on the probe.
.
In January 2002, AeroTech's
single-element gust probe thermal anemometer system was mounted
on the University of North Dakota's Citation research aircraft
(shown below), and flown in icing and turbulence conditions. Results
show the sensor to be stable and accurate throughout the flight
envelope, making high-frequency turbulence measurements more accurately
than accelerometer- or pressure-based turbulence measurements
that were being made concurrently.
A sample of the flight
data is shown below. In the top chart the vertical wind measured
from the two-element anemometer (purple line) is compared to a
5 second moving standard deviation of normal load (a measure of
turbulence intensity). Good frequency content is seen - this measurement
can also be used to calculate the angle of attack.
The lower
plot shows a comparison between the airspeed measured by a nose
boom pitot pressure probe (black line) and the anemometer (purple
line). The anemometer demonstrates much greater frequency content
which will be crucial in making a turbulence estimate.
Sample of Flight Data
