Momentum - March 2019 - 8

STUDENT
GENERATION

In flight at SAE Aero Design East 2018.

UNIMET SAE Aero Design captured second place with its Micro Class
plane at SAE Aero Design East 2018.

design process. As these airplanes are complex products, they can
be structured as a set of different interrelated subsystem levels and
components working together toward common aerial objectives. Each
subsystem level of the aircraft was evaluated based on different design
approaches, and the team selected the best approach, keeping in
mind those quantifiable expectations of flight performance organized
in objectives and key performance parameters (KPP). To define these
objectives and KPPs, first the team had to understand the rules and
principal constraints involved in the design process.
One of the most difficult challenges in the 2018 competition was
to select the correct amount of PVC pipes to lift, and their optimum
length, ensuring that all of them fit in the given container dimensions,
and leaving as much space as possible to also fit the aircraft system.
Hence, we proceeded to make a score analysis to determine the
required payload weight, considering that it is crucial to fly in all
competition rounds.
To study the storage alternatives and ensure the maximum use of space,
the team made use of SolidWorks software. After packing the payload, the

space available for the airframe was 11.825x13.625x1.000 in,
so it was important to calculate the optimal wing surface
that would ensure the estimated payload weight could
be lifted; in the same way, it had to allow room for the
tail and the propulsion system. For this reason, using an
analytical technique dependent upon aircraft performance
requirements such as stall speed, maximum velocity,
and rate of climb, the team was able to determine the
necessary wing area, as well as the required power for the
propulsion system. Additionally, some aircraft parameters
used in this technique were reinforced by analysis and
different empirical tests such as stability, drag, lift, and
thrust analysis, taking advantage of the university's lowReynolds number wind tunnel.
Once the prototype was manufactured, the team tested
the YV-UM09 on a flying field in Caracas at a density
altitude of 4700 ft. We managed to lift the maximum
total weight of 2.5 lb, which corresponds to a weight of 3
lb at the competition site's altitude given by the payload
prediction chart made for the town, and the weight that
indeed, Spirit of Caracas, managed to lift at competition.
Following the success of past years' competitions
(particularly the last one) and considering that rules
have not dramatically changed, this year's technical
approach was all about developing some of the design
concepts that our UAV prototype needed to improve and
assuring the main objective: winning first place in all four
categories of the competition.
By using the same systems engineering approach as
past years and breaking down the design process as
mentioned earlier, we focused this year on improving
three main aspects: faster assembly demonstration,
quantified and tested aerodynamics design of surfaces,
and increased propulsion and alternative tools.

FASTER ASSEMBLY DEMONSTRATION
Assembling the plane.
8 March 2019

Last year's assembly demonstration event was probably
the main reason why our prototype didn't assure the
first place overall. Only eleven points were the difference
between first and second place. UNIMET's demo score was

MOMENTUM
Momentum - March 2019

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