Aerocopter Calculations and equations

[sameh]

I posted two days ago about my first homemade helicopter size 600, today i will start with ''some'' calculations until i finish my first blog.
i want to tell you that i made my design on solid works software and knew its weight, CG and everything i want to know.
first of all we need to calculate Lift force, it is the upward force that ''lifts'' the vehicle.
to be honest; calculating aerodynamic forces is so difficult unlike fixed wing aircraft, we have a lot of losses and disturbance, so using some suitable approximations we can calculate everything easily.
The best losses we can get are from a wind tunnel.

starting with this equation:

L=0.5*ro*v^2 * A*Cl
where:

L is lift force
ro is air density
v is flow velocity
A is plan form area
Cl is the lift coefficient at the desired angle of attack, Mach number, and Reynolds number
in fixed wing we don't have a problem as flow velocity is aaprox. constant on the blade , but it is not in Helicopters as blades are rotating, so velocity is dependent on radius of rotation. exactly:
V=w * r
where :
w is rotational velocity in rad/sec
r is the radius
Image (4) may help you to understand that.
It is lift distribution on my blade (without tip losses, i will talk about that later).
so how can fix this problem?????
i tell you.....
we separate the blade into too small elements, and calculate the elemental lift on each assuming velocity is constant on the element, then we sum all elemental lift forces... we call it numerical solution.
really i want to explain everything here but calculations took me months to finish it, i will try to finish my blog as fast as i can then we discuss every thing.
the last image is RPM vs. angle of attack vs. Lift to redesign your model.
thank you...
sameh alsayed
samehdarwish92@gmail.com

facebook email : rona--92@hotmail.com