is anyone using SPAN for sailing yachts performance?

[yades]

Wd very much appreciate receiving some comments on how to obtain relevant leeway angle from SPAN results table?
anybody familiar with this software?

tks in adv

yades

[Andrew Mason]

Sorry, but SPAN does not calculate the leeway angle.

[yades]

Originally Posted by Andrew Mason

Sorry, but SPAN does not calculate the leeway angle.

Tks yrs

I understand leeway being not an idependent variable does not directly enter into the final solution or better saying into the final result table.
However, in reality (and I believe the software does it too), the hydrodynamic sideforce balances the aerodynamic sideforce as a result and the yacht will have to assume some leeway angle so as to produce such a sideforce.
Is in that respect that I believe SOMEHOW leeway values are to be used to compute the component of viscous drag on the appendages (keel fin and rudder)when they are producing lifting and SOMEHOW when incurring in calculation for effective span and moreover, when operating at different Froude Numbers and heeling angles. All that I believe is being determined by SPAN whilst performing some sort of regression analysis to derive coefficients, as it does, to describe the yacht's behaviour via using a......"balance equation".

Sorry for the length of this "abstract" but having accepted as you stated that SPAN doesn't do leeway calcn, my question wd again be is there any possible way to intercept a leeway angle of reference on the balanced out conditions or simply speaking a leeway angle range considered by SPAN for scoring the results thus obtained? Or which assumptions are then made in that respect to include a sort of allowance for the leeway angle?

Just that......

tks in adv yr rply

yades

[Andrew Mason]

The induced drag in SPAN is calculated using the sideforce derived from the rig loads, the velocity of the yacht and the effective span of the keel. Leeway angle is not required in the calculation, however you should be able to estimate it by taking the sideforce, the keel area and an approximation of the lift slope of the foils.