Space Grant Consortium - University of Wisconsin - Green Bay

Introduction
The analysis of wake vortex data is a very important factor in airport efficiency. These vortices
are normally not dangerous at typical flying altitudes, but become increasingly perilous to other
aircraft when encountered close to the ground. If an aircraft were to fly through the wake vortex
of a leading aircraft at a low speed and low altitude, there would be a high chance for the aircraft
to become unstable and crash.
To a void s ituations s uch a s t his, r egulations ha ve been i mposed t hat force d elays i n b etween
landings. Since the wake vortices are invisible to the naked eye, the only information about them
has been collected through lidar detection. There has been no reliable system developed thus far
to predict their motion, so the regulations are based on the weight of the plane that created the
wake vortices (2005).
However, this system can be very inefficient and creates useless delays because in most cases,
wake vortices decay much quicker than when predicted using the weight of the plane. If a model
were to be developed that predicted wake vortex decay more efficiently, landing schedules could
be pushed much closer together, leading to less delays and higher number of uses of each runway
every day.
Currently t here a re t hree accep ted m odels f or an alyzing w ake v ortices. T hese w ere d eveloped
using information gathered from lidar detection. The three analytical models are the Burnham-
Hallock Model¹, the Lamb-Oseen Model², and the TASS Initial Vortex Model³. The equations
and variables for these models can be found in Appendix A.
The purpose of this research has been to take steps toward the goal of developing a program to
compare the analytical models of wake vortices to actual collected data. If the two data sets can
be s hown t o co rrelate, t hese analytical m odels can be us ed t o m ake l anding pr ocedures m uch
more e fficient. The s pecific f ocus o f m y p art i n t his r esearch w as t o create a p rogram th at
compared t he experimental d ata co llected o n d ifferent as pects o f circulation pr operties in the
wake vortices as they decay.
Summary of Research
To b egin m y research o n w ake v ortices, I created a joined program that co mpared t he t hree
analytical models mentioned earlier with Ryan Coder and Tim Feyereisen. My part of the project
was to create the velocity profile for the Burnham-Hallock Model. The program allowed for the
input of variables affecting the velocity and for the placement of the lidar simulator. When run,
the pr ogram out put a c ontour pl ot of bot h vor tices a nd t he ve locity pr ofile a s t he l idar s wept
through the wake vortices. This program gave a baseline understanding of the project we were
working on as we split into our respective parts.
The purpose of m y final program was t o cr eate a G raphical U ser Interface ( GUI) t o i mport
circulation d ata an d allow t he u ser t o m anipulate t hat d ata i n o rder t o create p lots f or l ater
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