Turbulent flow structure in a cylinder-on-cone cyclone

Turbulent flow structure in a cylinder-on-cone cyclone was experimentally investigated. Measurements were conducted at a fixed geometrical swirl number. Experiments were performed at a swirl number of 3 and Reynolds numbers from 37,100 to 74,200, based on the inlet velocity and the cyclone body diameter. The flow field in planes normal to and through the cyclone axis was measured in detail using a two-component laser Doppler velocimetry (LDA) and a particle imaging velocimetry (PTV). Two dominant frequencies of vortical structures were identified based on LDA-measured tangential and axial velocity spectra. Although one of them agreed quite well with those in literature, the other was reported for the first time. One explanation was proposed.