In a numerical effort, wall jets over a convex wall (Coanda flows) are being investigated using direct numerical simulations (DNS) based on the spatial as well as on the temporal model. The focus of our numerical investigations is the development and interaction of large coherent structures in the turbulent Coanda flow. As observed in experiments, large spanwise "rollers" and longitudinal Gortler-type vortices can greatly influence the development of the jet along the surface and its eventual separation from the surface. From our spatial DNS of the Coanda flow over a cylinder segment, we found that both types of coherent structures can coexist. The presenence of these structures was also confirmed by preliminary temporal DNS of a narrow streamwise flow segment in the Coanda flow. The temporal DNS is capable of capturing coherent structures that are generated by local flow instabilities at significantly reduced computational expense.