Innovative Mechanical Solutions


Reducing Aerodynamic Drag on Zeva Zero

by | Mar 23, 2022 | Innovation Engineering, ZEVA

Company: Zeva Aero – eVTOL Aircraft
Tacoma, WA

Project: Zero Emissions Electric Vertical Aircraft

Request: Reduce the aerodynamic drag on Zeva Zero

What makes the Zero different from other drones is when it transitions to horizontal it becomes a flying wing and is much more aerodynamic than a traditional quadcopter drone. This gives the Zero its incredible range of 40+ miles. For efficiency the entire vehicle needs to be aerodynamic, so this project is about making the wheel struts aerodynamic.

Zeva Aero test flight, January 2022

After some initial brainstorming to figure out a lightweight, easy to construct airfoil, the decision was made to cut the aerodynamic shape out of rigid home insulation foam using a hot wire. The airfoil shape was made on CAD and a 3d printer printed model pieces. These pieces were used to shape the wire, which was connected to a power supply. 


How to cut rigid foam insulation with a hot wire.

Slow and steady feed of the foam was key to getting a consistent finished product.

The pieces were then sanded, and “low spots” were filled with lightweight putty especially made for foam. Bondo was considered, but Bondo melts styrene foam.

A few more iterations of sanding and filler, and the parts were ready for primer and paint. Initially the parts were primed and painted, but later it was determined this was not necessary. Attaching the parts to the aluminum extrusion was another brainstorm. Glue, Monocote, and shrink tubing were considered. Wrapping with 2” wide electrical tape was tested and did the job well. 1” wide electrical tape was used to cover the ends, and then the 2” wide tape wrapped the middle as in the picture below.

To determine the aerodynamic drag reduction, the aero profile was compared to the square tubing by Konstantin Matveev, at WSU, using Star-CCM+ software.

The airfoil has 56 times less drag than the square tubing. I personally found that borderline unbelievable, but the Aeronautical Engineers , just shrug their shoulders and say, “yea, sounds about right”.

In conclusion, we added 18 ounces of foam and electrical tape to reduce drag of the wheel struts by 56x, and ultimately increase the range of the Zeva Zero.