Helicopter inflow ratio calculator
Inflow ratio is a nondimensional measure of the flow speed normal to a rotor.
It's defined as the ratio of the normal flow speed \(V_{N}\) to the rotor tip speed \(\Omega R\).
Description
This calculator estimates the inflow ratio \(\lambda \) of a helicopter main rotor.
Equations
The following equations are used to estimate the inflow ratio.
\[ V_N = V\sin (\gamma  \theta ) + V_U \cos (\gamma  \theta ) + v_i \]
\[ \lambda = \frac{V_N }{\Omega R} \]
Many symbols are defined in
Helicopter Abbreviations and Symbols.
In addition, we use the following symbols here.
\(\gamma \) 
main rotor forward tilt 
\(V_N \) 
net downward flow speed, normal to the rotor 
\(V_U \) 
helicopter rate of climb 
