Momentum - October 2019 - 17

regulations. These principles led us to specific solutions,
which brought us to the competition in Michigan.
Specifically addressing the custom catalytic converter
design, sponsored by Peter Jensen at BASF, the TEX-2182
coated oxidation style catalyst was used in our system. To
maximize the oxidation rates in our exhaust stream,
we designed our system to have two of the catalysts
placed in parallel. With our engine specifications, two
converters oriented in parallel allowed for a lower space
velocity through the converters, which increased the time
for the exhaust gases to interact with the catalysts.
Along with space velocities, the other main concern
with an oxidation catalyst was the quantity of excess
air present in the exhaust stream. Excess air allows the
catalyst to properly oxidize the unburned fuels through
an exothermic reaction, thus significantly reducing
carbon monoxide and hydrocarbon pollution. Due to
the design of our common two-stroke engine, excess
air is pumped into the exhaust, which is a large source
of inefficiency. This guided our design to exclude an
external air pump, which otherwise is common in an
oxidation catalyst configuration for other engine styles.

issue with the fuel injection system, on day three of the competition
our catalysts were overloaded with fuel, which caused the wash coat to
become covered with a non-combustible layer of ash. This error seized
the operation of the catalytic converter.
This was an important learning event for the team, where we
concluded the crucial need for a functional prototype to have an agile
structural design. While in Michigan, the catalytic converters could have
been replaced with the correct maintenance and repair design, but our
catalyst housing had several permanent welded joints in the system.
This increased the time to replace the converter to more than what was
available at the competition. For the 2020 Clean Snowmobile Challenge,
we will iterate our design to be an easily replaceable system if the
catalysts need to be changed rapidly. 

Perhaps the most valuable part of this experience was the opportunity to
design, build, and personally test the extremes of an engineering project.
Planning and modifying a snowmobile to compete in the SAE Clean
Snowmobile Challenge developed our team's engineering skillset far
beyond our expectations. We learned more about engineering through
the hands-on application than we ever had in a classroom.

At the start of the 2019 Clean Snowmobile Competition,
our catalytic converter performed as expected, with the
decision to place the catalysts in parallel providing more
than enough conversion rates. Unfortunately, due to an

Aaron Juntunen, a senior pursuing a bachelor's degree in mechanical
engineering at Montana State University, wrote this article for MOMENTUM.
He was captain of the university's SAE Clean Snowmobile Challenge team
for 2018-2019 and will serve as technical design lead for the 2019-2020
team until he graduates in December 2019.

"We must find time to stop and thank the people who make a
difference in our lives. As we express our gratitude, we must
never forget that the highest appreciation is not to utter words,
but to live by them"
- John F. Kennedy
"Thank you."
These are two simple words that, when used together, have
more impact and meaning than words far more eloquent.
Unfortunately, these also are two words not said often enough.
So, to you, we say "thank you."
Thank you to those who participated, attended, volunteered,
and supported the 2019 SAE Aero Design competitions. For
over 30 years, SAE Aero Design has served thousands of
students in developing real-life skills necessary for successful
entry into industry. Without the collaboration of universities,
volunteers, organizers, and industry support, SAE International
couldn't achieve STEM initiatives like SAE Aero Design.


To all of you we say
thank you for your
time, your talents, and
your contributions
to SAE International.
We have produced
an SAE Aero Design
2019 Yearbook (online.
view/396582/) to
remind you of all your
at the two competitions. (Also check out this
Advanced Class video:
Collegiate Design Series

D e s i g n . B u i l d . C o m p e t e.

s a e . o r g / a t t e n d / s t u d e n t - e v
n t s | AutoDrive Challenge Yearbook | 1
Design. Build. Compete. 1

We look forward to the 2020 season and all
that the competitions have to offer.
Thank you,
The 2019 SAE International Aero Design Team

October 2019 17

Momentum - October 2019

Table of Contents for the Digital Edition of Momentum - October 2019

Momentum - October 2019
Getting a grip on costs
75 points
Major redesign
One-on-One – Kaitlyn Baron
It’s all about suspension simulation for Zuura Formula Racing
Engineering the future of two-stroke
Digital suspension keeps cabs stable
Motion sickness meets autonomous adaptable dynamics
SAE 101: Books
Miscellaneous news for SAE Student Members!
Dossier: Justin AndresMooi of Yanfeng Automotive Interiors
Momentum - October 2019 - Momentum - October 2019
Momentum - October 2019 - Cover2
Momentum - October 2019 - Contents
Momentum - October 2019 - EDITORIAL
Momentum - October 2019 - BRIEFS
Momentum - October 2019 - STUDENT GENERATION
Momentum - October 2019 - 5
Momentum - October 2019 - 6
Momentum - October 2019 - Getting a grip on costs
Momentum - October 2019 - 75 points
Momentum - October 2019 - 9
Momentum - October 2019 - Major redesign
Momentum - October 2019 - 11
Momentum - October 2019 - 12
Momentum - October 2019 - One-on-One – Kaitlyn Baron
Momentum - October 2019 - It’s all about suspension simulation for Zuura Formula Racing
Momentum - October 2019 - 15
Momentum - October 2019 - Engineering the future of two-stroke
Momentum - October 2019 - 17
Momentum - October 2019 - Digital suspension keeps cabs stable
Momentum - October 2019 - Motion sickness meets autonomous adaptable dynamics
Momentum - October 2019 - SAE 101: Books
Momentum - October 2019 - Miscellaneous news for SAE Student Members!
Momentum - October 2019 - Dossier: Justin AndresMooi of Yanfeng Automotive Interiors
Momentum - October 2019 - 23
Momentum - October 2019 - 24
Momentum - October 2019 - Cover3
Momentum - October 2019 - Cover4