How Bladed calculates the optimal mode gain K_opt;
Why there is a difference between automatically calculated K_opt and the manually calculated K_opt based on the same Performance Coefficients Simulation?
In Bladed, the nominal rotor diameter(in the "Rotor" Screen) will be used to calculate the optimal mode gain.
After a "performance coefficient" calculation, Cp- λ data can be obtained. An interpolation will be used to find the maximum Cp and the corresponding λ value. These interpolated values are then used by Bladed to find K_opt based on the following equation (from the Theory Manual)
It is this interpolation that is likely the root cause of the discrepancies comparing to the manually calculation. Users can reduce the "Tip Speed Ratio Step" in the performance coefficient calculation parameter settings in order to get a consistent optimal mode gain.
