The transitional regime of pulsatile pipe flow

The presence of turbulence in the circulatory system is thought to lead to cardiovascular diseases. Despite its importance, turbulence transition in cardiovascular flows is not well understood. In particular, it is unclear which one of the numerous complex features of blood flow (unsteady driving, rheology, flexible walls, complex geometry...) is the dominant one in terms of turbulence transition. The main aim of this thesis is to single out the effects of one of these features: the unsteady driving of the flow. Specifically, the case of a pulsatile driven, Newtonian fluid, in a rigid smooth pipe of circular cross-section is considered, referred to as pulsatile pipe flow. Two main questions are investigated: whether and how laminar pulsatile pipe flows transition to turbulence, and how turbulence behaves once triggered. Pulsatile pipe flows in the transitional regime, with a mean 1000