Present state of art on pulsatile flow theory -: (Part 1:: Laminar and transitional flow regimes)

Pulsatile flow is a specific unsteady flow in which the resultant flow is composed of a mean component and a periodically varying time-dependent component. Oscillatory flow is a sub-branch of pulsatile flow with zero mean component. Pulsatile flows may appear in one of the flow regimes: laminar, transitional or turbulent. In this paper, the basic terminology and relationships for pulsatile flows are presented, based on published theoretical and experimental investigations to date. The available theory on laminar and transitional regimes is outlined. Although the primary purpose of the study is to determine the theory of pulsatile pipe flows, published papers on related flow fields are also reviewed.