UAV solar loiter flight

Project Soare

Mission Objective:

2 week flight time

all powered by the sun

Students task....

Start researching the subject. Learn from what has been done, what has been tried. (See videos below)

Start looking at solar films that are capable of powering our UAV

start looking at prototype air-frames for testing materials and concept. Vehicles to start flying.

Some possible prototype air-frames ....

https://drive.google.com/file/d/0B3TmuoXy5GuSWUUwdEJXN1RUZlE/view?usp=drive_web

Gilbert area students

Richmond/Spring Grove

EVIT

March 1st, 2018 first test of the solar plane....

So the section of solar cells that we added to the center of the air-frame made the airplane very unstable.

The airplane has 42 solar cells installed. The were configured in parallel.

The configuration gave us 12v at 12amps or 144 watts of power available.

We decided to do one more test with the Radian.

We stripped the center section of cells off the airplane.

We now have 32 cells installed. We rewired the airplane so that all of the cells are configured in series.

The 32 cells in series give us 18.56v at 6amps or 111watts of power.

May 8, 2018

After eliminating the 10 cells in the middle of the fuselage and rewiring the cells, it was discovered that some of the cells were damaged and limiting our power output.

Theoretically we should have had the following power output.

Each cell should produce .58v(Vmpp) at 6.01a(Impp) for 3.49wp(Pmpp) per cell

After re-configuring the cells, we ended up with 32 cells, which should have yielded the following...

32 cells each producing 3.49wp should yield 111.68wp

32cells at .68v(Voc) = 21.76v(Voc)

in our test results we got 17.4v (Voc)

The maximum amperage that we pulled was 4.5amps

The maximum power output was 4.27a(Impp) at 10.24v(Vmpp) = 43.72wp(Pmpp)

Thus was well below our theoretical value of 111.68w

The conclusion

We need to be much more diligent in handling the solar cells. They are extremely fragile.

"A solar cell is basically a current source shunted by a diode (the latter is what determines Voc). If a damaged (or shaded) cell has a lower maximum current, it limits the current through the entire string, which has a huge effect on Pmax."

Damage cell info

Solar plane V2...

Students should be designing a wing for our next airplane.

We are going to install a Cobra CM-4515/18 435kv motor and a RC timer 17X5.5-CF prop.

EVIT students, your homework

Design a wing from the information below.

Use the rib section from below (SD 7037)

The rib will need to be modified to accomodate cabon fiber tubing