The solar cells
So I came around this litttle toy:
A solar cell sizes 125mmx125mm weighing 8g each panel, and outputting a maximum of 3W each.
They can be bought here.
I got 10 of these, and decided to try and build a solar powered glider using all 10 of them. The setup should give me 30W with good solar radiation, so the excedent will be used to charge the battery of a low-weight brushless motor, for when gliding isn't enough.
First, I needed an overall idea of how the plane would be, since I'm not the greatest designer, I decided to see what I could find online. Searching Google, I found Aerofred and there, I found this plan:
With the plans, I could start working. Off to Autodesk Inventor (Free for students), I created a 3d model of the plane.
Besides the 3d model itself, I could play with the scale while on this part. A bigger plane would have more space for the cells, but requiring more power to stay aloft. PLaying with the dimensions, I decided for a 2.35m wingspan, which can be seen on the previous picture. This setup allowed me to keep all the solar cells on the main wing panel.
Playing with XFLR5
With all the data I had, I could assemble the project on XFLR5 and do some tests: The setup was somewhat ease, but it needs to simulate the airfoils on A LOT of conditions in order to do the whole body simulation. I got this:
There are some wingtip vortexes, but since I'm no aerodesign expert, I accepeted this as good enough.
To connect the wings to the fuselage, and create the first 3º dihedral, I Designed a new piece, a kind of sleeve supposed to fit the foam wing, connect to the 5 fiber glass rods(small holes) and 2 harder spars (bigger holes).
After printing (PLA, 190ºC, 0.3mm layers), the piece is pretty much perfect for my needs:
The wings were cut by using a drilled profile of the airfoil ( I found on the internet that it used the e216 profile).
This is the result after cutting:
The wing was then cut to receive the solar cells. It got the glass fiber rods, two on top and two on the bottom, and then a layer of thick paper (Vergê) here in Brazil. Finally it was wrapped in vinyl.
With the wing now reinforced, the solar cell slots where re-cut (through the vinyl). As they were slightly misaligned, some time was spend testing the fitting of the solar cells on each slot. Sadly one of them got broken on the process, as THEY ARE EXTREMELY FRAGILE!
I Currently have this:
THIS PROJECT IS ONGOING!