A nozzle and a method of generating an inhalable aerosol from a liquid solution or liquid suspension and a gas by operating the nozzle. A column-like aerosol plume is generated having fluid particles within a particle free sheath of gas, the aerosol plume being generated from a compressed gas interacting within the aerosolizing space with a fluid ejected along the central axis, and generates a Venturi effect entraining gas that flows over the convex outer nozzle surface that together with the particle free sheath keeps the circumferential edge and the outer nozzle surface free of particle deposition. An aerosol exit orifice diameter is at least 1.3 times larger than the fluid exit orifice diameter; and a converging annular pressurized gas channel extending at an acute gas flow angle of 10-30° with respect to a central axis.