  We present a parameter study of self-consistent models of protoplanetary
disks around Herbig AeBe stars. We use the code developed by Dullemond and
Dominik, which solves the 2D radiative transfer problem including an iteration
for the vertical hydrostatic structure of the disk. This grid of models will be
used for several studies on disk emission and mineralogy in followup papers. In
this paper we take a first look on the new models, compare them with previous
modeling attempts and focus on the effects of various parameters on the overall
structure of the SED that leads to the classification of Herbig AeBe stars into
two groups, with a flaring (group I) or self-shadowed (group II) SED. We find
that the parameter of overriding importance to the SED is the total mass in
grains smaller than 25um, confirming the earlier results by Dullemond and
Dominik. All other parameters studied have only minor influences, and will
alter the SED type only in borderline cases. We find that there is no natural
dichotomy between group I and II. From a modeling point of view, the transition
is a continuous function of the small dust mass. We also show that moderate
grain growth produces spectra with weak or no 1um feature, both for flaring
(Group I) and non-flaring (Group II) sources. The fact that sources with weak
features have been found mostly in Group I sources is therefore surprising and
must be due to observational biases or evolutionary effects.
