nucleus
Well-Known Member
I have been playing around with what I call a flying boat - meant to be more boat than aircraft.
My 1:12 scale model was overweight, and rough; it did not fly.
Pending my rebuild, I have been noodling some numbers.
Here are some screen captures from an app on my phone called Airfoil Performance.
This first one is 33 MPH, 20 degrees angle of attack
This one is 28 MPH, 20 degrees angle of attack
Here is the input value screen for the 28 MPH calculation. The only difference between the two is the speed. The calculations are for a 1 meter wide strip of airfoil.
So, with my 18 foot "wingspan", I multiply the numbers by 5.5 to get an estimate of the actual values.
So for the 28MPH lift number, I get 2967.31 Newtons x 5.5 = 16,320 Newtons = 3669 pounds of lift.
At 33 MPH I get 5098 pounds of lift.
I am encouraged by these numbers - if I could possibly keep the weight down to 2200 pounds, I could potentially load 1500 pounds of people, luggage and fuel and potentially still takeoff at 26 Knots.
This is a custom airfoil that I arrived at after reading some WIG papers and applying some common sense boating knowledge from growing up on the water.
My design has lots of fencing to aerodynamically increase wingspan without making the craft wider, so it may generate more lift at a lower speed than these simple calculations indicate.
My 1:12 scale model was overweight, and rough; it did not fly.
Pending my rebuild, I have been noodling some numbers.
Here are some screen captures from an app on my phone called Airfoil Performance.
This first one is 33 MPH, 20 degrees angle of attack
This one is 28 MPH, 20 degrees angle of attack
Here is the input value screen for the 28 MPH calculation. The only difference between the two is the speed. The calculations are for a 1 meter wide strip of airfoil.
So, with my 18 foot "wingspan", I multiply the numbers by 5.5 to get an estimate of the actual values.
So for the 28MPH lift number, I get 2967.31 Newtons x 5.5 = 16,320 Newtons = 3669 pounds of lift.
At 33 MPH I get 5098 pounds of lift.
I am encouraged by these numbers - if I could possibly keep the weight down to 2200 pounds, I could potentially load 1500 pounds of people, luggage and fuel and potentially still takeoff at 26 Knots.
This is a custom airfoil that I arrived at after reading some WIG papers and applying some common sense boating knowledge from growing up on the water.
My design has lots of fencing to aerodynamically increase wingspan without making the craft wider, so it may generate more lift at a lower speed than these simple calculations indicate.
