Boundary-layer control by means of strong injection

The gas mixture produced by a coal gasifier contains components which have serious corrosive effects on the walls of the pipe flow system. To reduce these, a noncorrosive gas is injected into the stream of the coal gas products, in a direct parallel to the pipe wall. The interaction between the injected stream and the original pipe flow is investigated analytically and is an example of the so-called Wall Jet Problem. The model adopted is that of a two-dimensional incompressible turbulent free mixing layer, with the corrosive gas H2S forming the upper stream and moving faster than the injected non-corrosive gas in the lower stream, the latter bounded by the solid wall of the pipe. This wall jet flow can be divided into three distinct regions.