The paper exposes some facets of computational research undertaken at UMIST over the past few years, directed towards the use of second-moment closure for predicting physically and geometrically complex 3D flows. The modelling foundation and the numerical framework are summarised, and a selection of solutions is presented for several 3D flows, one of which is transonic. The solutions demonstrate that turbulence modelling is an influential element in the prediction of complex 3D flows and that reverting from eddy-viscosity models to second-moment closure can have a significant impact, at modest additional costs, not only on turbulence quantities but also on mean-flow features.