process for making visible of currents

摘要

In a process for the vistualisation of flow over solid surfaces, the surface is coated with a wet soln. of MnCl2 contg. H2O2, anbd an air stream contg. NH3 or methylamine is passed over the surface. Due to local diffusion and absorption effect, colourisation reactions occur on the surface of the body to give an immediate visual indication of the flow over the body by way of the varying colour intensity of the colour produced in different areas of the surface. The process is esp. useful for determining the air flow over articles such as vehicle bodies, aerodynamic aircraft, turbine blades, ceramic articles, heat exchangers, driers, architectural models, etc.