Turbulent swirl flow analysis by Kolmogorov's similarity hypotheses

Turbulent swirl flow generated by the axial fans in pipe is investigated in this paper by using Kolmogorov's similarity hypotheses. It is shown that energy in the inertial subrange is divided among eddies after the “−5/3” law, i.e. Φ ww ∝ f −5/3 , where Φ ww is spectral density for circumferential velocity and f is the frequency. This is presented for two various axial fans, of which one is carefully designed to generat Rankine vortex, while the second one has solid body circumferential velocity profile.