A novel seeding technique for the flow visualization of pressurized air flows

This design note describes a novel seeding technique for pressurized air flows. The method utilizes the combustion of readily available smoke pellets which are both cheap and practically very simple to incorporate into an experimental set-up. The particles produced are spheres of zinc chloride (ZnCl2) with a mean diameter of 0.5 mu m and a density ratio of 2.5 x 10(3). The particle properties compare favourably with those of the more widely used TiO2 and MgO. A laser light-sheet investigation of gas-leak jets has been presented as an example of the application of this seeding technique.