  The protoplanetary discs of T Tauri and Herbig Ae/Be stars have been studied
by using geometric disc models to fit their spectral energy distribution (SED).
The simulations provide means to reproduce the signatures of different
circumstellar structures, which are related to different levels of infrared
excess. Aiming to improve our previous model that assumed a simple flat disc
configuration, in the present work we adopt a reprocessing flared disc model
that considers hydrostatic, radiative equilibrium (Dullemond et al. 2001). We
developed a method to optimise the parameters estimation based on genetic
algorithms (GA). This paper is dedicated to describe the implementation of the
new code, which has been applied for Herbig stars from the Pico dos Dias Survey
catalogue, in order to illustrate the quality of the fitting for a variety of
SED shapes. The star AB Aur was used as a test of the GA parameters estimation,
demonstrating that the new code reproduces successfully a canonical example of
the flared disc model. The GA method gives good quality of fittings, but the
range of input parameters must be chosen with caution, since unrealistic disc
parameters can be derived. The flared disc model is confirmed to fit the
flattened SEDs typical from Herbig stars, however the embedded objects
(increasing SED slope) and debris discs (steeper SED) are not well fitted with
this configuration. Even considering the limitation of the derived parameters,
the automatic process of SED fitting provides an interesting tool for the
statistical analysis of the circumstellar luminosity of large samples of young
stars.
