I am building an RC plane (for the first time. I am doing it for a competition) with a twin boom configuration like this:
My wing shape is like this:
I decided that the lift should be 0.8g and I need to use this equation to find the wing area (as per the instructions)
$$F_l=\frac{1}{2}\rho v^2 S C_d$$
$F_l=0.8$
$\rho=1.225$
$v=12m/s$
Can you help me in figuring out the value of $C_d$ considering that I am using Clark Y aerofoil design?
After that, I will measure $b$ using the aspect ratio.
$$\frac{b^2}{S}=\text{Aspect Ratio}$$
My instructor asked me to obtain a wing span of 80-100cm. So I will have to choose Aspect ratio as well.