Airfoil
Three airfoils were chosen to represent a variety of camber and thickness for NACA 4 digit airfoils. They were evaluated based on the lift coefficient at the highest L/D operating point, the thickness, the drag at operating point, and the width of the Cl/Cd bucket. Each of the standardized NACA airfoils adhere to the design specifications but provide separate benefits in terms of the client requirements. The model airfoil model can be seen on the left. The selection button below shows how we selected the airfoil.
Wing Configuration
Several wing design options were researched and modelled according to the design specifications provided. The models were evaluated based on cost, aesthetics, manufacturability, complexity, and motor mount compatibility. The selected design can be viewed on the left.
Motor Mount
The optimal number of motors along the wing was found to be 12. This relatively large number makes the importance of motor mount design much higher as the impact of a single mount will be multiplied twelve-fold. It was found that the optimal rotor hub location relative to the leading edge of the wing is half of the blade radius. It was requested by the client that multiple propeller sizes are tested, which will require a mount that can optimally locate a variety of prop sizes. To the left is the final design that our team modelled.
Test Setup
The test set up consisted of mounting the wing and electrical components to a vehicle for car top testing of the wing. The requirements laid out by CFAR stated that the wing must be located approximately a meter above the roof to reach “clean” airflow. The car mount must be able to support the wing while the vehicle is travelling about 30 km/h, be easy to assemble and disassemble, and must mount to roof rack bars. CFAR also requested an economic design to allow for the major budget be focused upon the wing and electronics design. The car top mount was a simple wooden design and can be seen in the images on the final prototype page.