Design Build Fly

Background:

Design Build Fly is an annual competition hosted by the American Institute of Aeronautics and Astronautics (AIAA). Each year, AIAA publishes a new set of rules for the DBF competition. For the upcoming 2021 DBF competition, candidates will be required to design, build, and test an aircraft with a towed sensor. The competition was planned to take place in Tucson, Az during 15 - 18 April 2021. However, due to the on-going pandemic, AIAA has announced that the 2021 DBF competition will be performed virtually. This year, our team has decided not to attend the DBF competition but still follow the design requirements and finish the project by the 2021 spring quarter.

Goal and Objectives:

The competition for this year consists of three Flight Missions and one Ground Mission:

- Flight Mission 1: The aircraft must complete three laps within a 5-minute flight window.

- Flight Mission 2: The aircraft should complete three laps as fast as possible while carrying the maximum amount of payloads.

- Flight Mission 3: The aircraft should complete as many laps as possible within a 10-minute flight window. The aircraft will also be required to deploy the sensor after the takeoff, perform a 360-degree turn for every lap, and recover the sensor before the landing.

- Gound Mission: Team members will demonstrate that the shipping container can protect the sensor in free fall testing. Team members are required to install and uninstall necessary components for Flight Mission 2 and Flight Mission 3 as fast as possible.

Point anlysis showed that a focus on mission 3 would yield higher combined points than focusing on mission 2. As such the plane will be designed for maximum sensor length and cruise speed. This will be done by minimizing the drag and weight of the aircraft and sensor. The fuselage dimensions are limited by the sensor size and the deployment and retraction method. As such the primary focus will by on optimizing the wing design by utilizing the highest aspect ratio possible. As long as the plane maintains takeoff performance this will yield the lowest drag for both surfaces. Additionally the construction method will be selected between foam and balsa structures as those are the two most prominent methods.

Takeoff Field Length;

- 100 ft

Sensor:

- minimum diameter of 1.00 in with a minimum length to diameter ratio of 4

- aerodynamically stable while deploying

Batteries:

- NiCad/NiMH or Lithium Polymer (LiPo) batteries

- 200 W hr maximum

For more information on the 2021 DBF competition and the rules, visit <https://www.aiaa.org/dbf>

Progress:

All individual aspects of the plane have been designed and assembled. With this information the drag can be calculated in flight using the flat plate area, and from this the power required for flight can be calculated. As our goal is to maximize flight speed we will aim to use all of the battery and as such we select the velocity corresponding to that value. This method resulted in our current value of cruise velocity as 63 ft/s. Additionally with every part modeled and most of the balsa wood structures cut out and weighed, a more accurate weight was calculated as 6.134 lbs. From this we are also able to balance the center of gravity around the quarter chord of the wing to maintain stability. The resulting configuration is shown below in the following two pictures.

Aircraft Configuration:

https://i.imgur.com/KVIH6Go.png

https://i.imgur.com/gTYNKgS.png

Future Plans:

Finish construction for wings, tails, fuselages in the summer by September.

Finish assembly and test flights in early September.

Prepare theoretical calculations for next year's aircraft.

Contact:

Aircraft Team: Teagan Adsit, tadsit@uci.edu

Mechanism Team: Leo Zheng, leoz2@uci.edu

Sensor Team: Rex Guo, zehaog2@cui.edu

Manufacturing: Weixiao Wang, weixiaow@uci.edu