A NOVEL SEEDING TECHNIQUE FOR THE FLOW VISUALIZATION OF PRESSURIZED AIR-FLOWS

This design note describes a novel seeding technique for pressurized a ir flows. The method utilizes the combustion of readily available smok e pellets which are both cheap and practically very simple to incorpor ate 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 invest igation of gas-leak jets has been presented as an example of the appli cation of this seeding technique.