Blasius–Chaplygin formula

The Blasius–Chaplygin formula, deviced by Sergey Chaplygin from the work of Heinrich Blasius relates the force L ¯ given by a complex velocity field f

L ¯ = i p 2 ∫ γ f 2 ( z ) d z

The equation stated above appears from the analysis of the velocity over a body with a boundary γ , taking Bernoulli's law into consideration.