adamalbert
Member
Our team is building a circular wing for the San Francisco Flugtag.
We have built several glider models.
They don’t have ‘airfoils’. They have the same cross section as the Gremyatsky "Disc". see link for diagram
Real Soviet glider-diskoplan (
They all have a circular wing 20” in diameter.
I have varied the thickness, and the location of the thickest point.
A flat plate wing
A 25% thick (5”) in the center of the wing
A 15% thick (3”) in the center of the wing
A 25% thick (5”) 25% back from leading edge
A 15% thick (3”) 25% back from leading edge
I have tested them by consecutively gliding the models: the first, then second, then third, etc., then back to the first for a total of 10 times each. I then averaged the distances for each model.
The issue I am having is that the glide ratio is basically the same for all 5 models: between 11.7/1 to 12.2/1 this doesn’t seem right to me. It seems that there should be more of a delta. Do you have any ideas?
Our San Francisco entry video (we haven’t not been accepted to compete yet) This will give you an idea of some of our aircraft inspiration: Arup, flying pancake, Disoplan etc
Flugtag2012f - YouTube
I appreciate any thinking you have on the subject. Keep in mind that due to the rules a high A/R wing isn't possible.
Thanks
Adam
We have built several glider models.
They don’t have ‘airfoils’. They have the same cross section as the Gremyatsky "Disc". see link for diagram
Real Soviet glider-diskoplan (
They all have a circular wing 20” in diameter.
I have varied the thickness, and the location of the thickest point.
A flat plate wing
A 25% thick (5”) in the center of the wing
A 15% thick (3”) in the center of the wing
A 25% thick (5”) 25% back from leading edge
A 15% thick (3”) 25% back from leading edge
I have tested them by consecutively gliding the models: the first, then second, then third, etc., then back to the first for a total of 10 times each. I then averaged the distances for each model.
The issue I am having is that the glide ratio is basically the same for all 5 models: between 11.7/1 to 12.2/1 this doesn’t seem right to me. It seems that there should be more of a delta. Do you have any ideas?
Our San Francisco entry video (we haven’t not been accepted to compete yet) This will give you an idea of some of our aircraft inspiration: Arup, flying pancake, Disoplan etc
Flugtag2012f - YouTube
I appreciate any thinking you have on the subject. Keep in mind that due to the rules a high A/R wing isn't possible.
Thanks
Adam
