Free flow flow-rate for OVOIDAL cross section pipes

The app returns the flov velocity and flow rate in a OVOIDAL cross-section pipeline in free-flow conditions
% Filling rate
Design flow-rate

Pipe data   
Pipe dimensions (cm x cm)
Pipe nominal radius (m)
Roughness coefficient   
Gauckler-Strickler (G-S)Ks(m1/3s-1)
Design filling rateh/R( )
% Filling rate %
Flow data   
Inclinationi( )
A/r2 ratioA/r2( )
R/r ratioR/r( )
Wet areaA(m2)
Hydraulic radiusR=A/P(m)
Avg flow speedv(m/sec)
Design flow-rateQ(m3/sec)