The turbulent buoyant jet in a nonuniform cross-now is formulated usin
g a general integral method. The integral equations for the turbulent
motion through the jet cross section are derived for a fixed control v
olume and expressed in vector form. In contrast to previous work, the
new formulation does not require the a priori assumption of a velocity
and concentration distribution. Coupled with a Lagrangian jet spreadi
ng hypothesis and the inclusion of added mass effect, the model is sho
wn to predict correctly the properties of the asymptotic flow regimes
in both the near field (straight jet and plume) and the far field (adv
ected line puff and thermal). Predictions of the path-averaged jet pro
perties are shown to be consistently supported by experimental data on
visual trajectory and jet width, and centerline minimum dilution. The
relation between the present formulation and previous Lagrangian/Eule
rian models is also discussed.