In the axial blast type air flow Fig. 2.6 (a) the flow air is longitudinal, along the arc. In
axial blast type air flow, the air flows from high pressure reservoir to the atmospheric
pressure through a convergent divergent nozzle. The difference in pressure and the design
of nozzle is such that as the air expands into the low pressure zone, it attains almost
supersonic velocity. The mass flow of air through the nozzle is governed by the
parameters like pressure ratio, area of throat, nozzle throat diameter and is influenced by
the diameter of the arc itself.