2 pages due Thursday morning

This paper is a summary of the project designed to accomplish Outback Challenge Mission. The design research focuses on the UAV that is ideal for the mission, from the structures of the Aircraft including the airframe, engine, and propeller /rotors. The aircraft selection is built and UAS system customized to meet the purpose of search and rescue of Outback Joe. The core of the research of the UAV is the vertical takeoff and landing and adheres to the criteria of the Outback Challenge rules. The selection of the type of aircraft is based on its ability to not only search and find Outback Joe, but to also get him supplies to survive.

The main aim of the research project is to build and design a Search and Rescue Unmanned Aerial Vehicle (UAV) that is customized only for search and rescue and not the recreational purpose. The UAV structures use the background of Aerospace and Mechatronic disciplines that are objectively focused on building and developing an autonomous UAV platform using ground based control and surveillance capabilities (Avalakki, et al., 2012). The UAV developed in this research is a typical drone technology that will take off from an airdrome, locate the mannequin, Outback Joe, and deliver a 500ml bottled life giving-water through air drop. The entire UAS system shelf items will not exceed $10,000.

To accomplish the design project for the Outback Mission Challenge the selection of aircraft was very crucial for vertical takeoff and landing. The main aim of the research is to use an Unmanned Aerial Systems (UAS) whose engine and propellers are purposefully and expertly designed for small, low attitude that requires fuel-efficiency and portable power generation. It was important to choose a propulsion system that fits the projected aerial vehicle weight class and easily plugged with little or no modifications. This research is centered on the type of engines designs from various UAV manufacturers.

This research seeks to come up with a UAS that has the most power efficient, long lasting and reliable engine for the project. The following engines from Northwest UAV were considered; NW44 single- cylinder multi-fuel engine was found to be the most configurable small UAV propulsion system designed for aircraft in 18 to 35 kg weight class. It is also easily scaled with multiple configurations hence giving it the flexibility that is not found in hobby based engines.

NW-88 Twin- cylinder Multi-fuel engine has a design element of NW-44 which is designed for aircraft in 29 to 68 kg weight class. It is durable and reliable for large aircraft. NW-500 Twin- Cylinder gas UAV engine is designed for aircraft of up to 250kg weight class. The latter two engines were too big to work on Outback Challenge, and the research has led to the choice of the NW44 single- cylinder multi-fuel engine. The key features of the NWUAV engines include the ready-to-fly commercial off-the shelf, they are designed to maximize endurance, they have multiple generator output configurations, and they are light weight.

The other area of the research conducted was the propeller design. Propellers are one the fundamental elements of propulsion and aircraft design. A propeller blade is a rotating airfoil, which is similar to an airplane wing which produces lift and drag (Tracy, 2011). The search and rescue Outback Mission Challenge requires UAV that can have a vertical take-off landing to drop a live –saving 500ml water bottle. From the research it was found that propellers between 24’’-36’’ in diameter and powered by internal combustion engines were found to be more effective for the mission.

The potential of the UAV propeller is made up of several different facets such as the how many blades are needed, what are the dimensions of the blades, what is the diameter of the hub, the shape of the airfoils, chords, pitch dispersal and coning angle. This research was looking for a propeller design with a distinctive answer to an elliptical lift dispersal along the span of the blade for effective use. The goal of this research was to find a propeller whose aerodynamic design generated enough vertical thrust to notably reduce energy loss and improve the translation of input energy to thrust overall.

The study sought to use a propeller with specific design criteria with operating conditions that offers optimized design and geometry for the best aerodynamic performance. Further, low noise propeller design was considered. The NW UAV's variable pitch propeller systems were found to have the design for all UAV and featured all – electric actuation system. They are also designed for light weight AUVs that expand on-station duration and enhance engine performance by allowing lesser RPM engine speed. The propellers improve the amount of thrust for vertical takeoff and lower the auditory signature with enhanced design and the ability to alter pitch.

References

Avalakki, N., Bannister, J., Chartier, B., Downie, T., Gibson, B., Gottwarld, C., et al. (2012). Design, Development and Manufacture of a Search and Rescue Unmanned Aerial Vehicle. Aerospace Robotics .

Ambrose-Thurman, Andrew, Michael, Luke (2014). Autonomous, Collaborative, Unmanned Aerial Vehicles for Search and Rescue. Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/10652.

F. Delle Fave, A. Rogers, Z. Xu, S. Sukkarieh, and N. R. Jennings,(2012) “Deploy-

ing the max-sum algorithm for coordination and task allocation of unmanned

aerial vehicles for live aerial imagery collection,” in Robotics and Automation, pp. 469–476.

Tracy, I. P. (2011). Propeller Design and Analysis for a Small, Autonomous UAV.