A shroud for the cooling fan of a motor vehicle engine provides a circumferential axial flow of air between the fan blade tips and the shroud to improve fan efficiency and engine cooling. The shroud may include a circumferentially extending Coanda surface and adjacent circular throat which directs air flow toward the annulus between the shroud and the fan blade tips. Adjustment of the air pressure and throat dimension allows accurate control of the velocity profile of the air flow through the annulus.