β Scribed by B. B. Lieber; D. P. Giddens
No coin nor oath required. For personal study only.
An autoregressive spectral estimation technique is applied to describe the frequency content of velocity disturbances created by pulsatile flow through a constricted tube. The Reynolds number and frequency parameter are such that transitional phenomena, including vortex formation and coherent disturbances, as well as turbulence, are created during various phases of the pulsatile cycle. Although under some circumstances Fourier methods of spectral estimation suffer from poor frequency resolution and large variance under these unsteady flow conditions, the autoregressive technique is shown to be capable of identifying essential flow disturbance features with good resolution and considerably smaller statistical variation. This method should be particularly useful in analyzing energy spectra of flow disturbance variables under unsteady mean flow conditions or when a limited amount of data is available.
π SIMILAR VOLUMES
The effects of pulsatile amplitude on sinusoidal transitional turbulent flows through a rigid pipe in the vicinity of a sharp-edged mechanical ring-type constriction have been studied numerically. Pulsatile flows were studied for transitional turbulent flow with Reynolds number (Re) of the order of
Pulsatile flows in the vicinity of mechanical ring-type constrictions in pipes were studied for transitional turbulent flow with a Reynolds number (Re) of the order of lo4. The Womersley number (Nw) is in the range 3CL50, with a corresponding Strouhal number (St) range of 0.0143-O-0398. The pulsatil