Abstract: A laminar flow nacelle for an aircraft engine, the nacelle having an outer member defining an aerodynamic shape for a fluid, an inner member defining a chamber with the outer member, and an inlet pipe fluidly connecting ambient air with the chamber for ventilation thereof, the nacelle comprises a porous region at a first region of the outer member, the porous region arranged to allow a flow of fluid into a duct, characterised in that the inlet pipe comprises a venturi portion having a narrow low pressure part and the duct is connected to the narrow part to provide suction to the porous region.