Vortex structure and pressure pulsations in a swirling jet flow

Both experimental and theoretical studies of swirling flow with structure in a form of precessing vortex core (PVC) have been carried out. LDA and acoustic technique have been employed to explore instantaneous and averaged structure of the unsteady flow. The theoretical approach is based on a model of vortex with a core in form of helical rope of circular cross-section. It is found tat in a special case of uniform vorticity distribution the Euler equations can be integrated to yield relation between the pressure and velocity fields. The model describes well the experimental velocity distributions and gives satisfactory prediction for the pressure field.