Numerical simulation of the flow through the blades of a swirl generator

• The dynamics behavior of swirling jets has been investigated for three blade-type swirl generators.
• The effect of the swirl angle and the Reynolds number on the flow field has been analyzed.
• The dynamic analysis shows a special vortex flow.
• Inside the swirl generator, the tangential velocity increases from the upstream to the downstream.
• The intensity of swirling motion depends on the blade angle and it decays rapidly along the axial direction.

This paper aims at analyzing the dynamics behavior of the flow generated by blade swirlers. Three-dimensional calculations are carried out for different Reynolds numbers and blade angles (θ=20∘,30∘,θ=20∘,30∘, and 45°). Flow field characteristics within the swirler and in the outgoing jet are examined in detail. Results are discussed in terms of the axial and circumferential components of the turbulent velocity field, on the basis of a swirl number to qualify the complex flow field. The results obtained for the different configurations reveal that a vortical structure is present at the inlet of the swirl generator and it is identified at the jet exit. Its intensity depends on the blade angle.