Sökning: "pulsatile flow"
Visar resultat 1 - 5 av 36 avhandlingar innehållade orden pulsatile flow.
1. Flow measurements related to gas exchange applications
Sammanfattning : This thesis deals with flow measuring techniques applied to steady and pulsating gas flows relevant to gas exchange systems for internal combustion engines. Gas flows in such environments are complex, i.e. they are inhomogeneous, three-dimensional, unsteady, non-isothermal and exhibit significant density changes. LÄS MER
2. Numerical computations of the unsteady flow in a radial turbine
Sammanfattning : Non-pulsatile and pulsatile flow in bent pipes and radial turbine has been assessed with numerical simulations. The flow field in a single bent pipe has been computed with different turbulence modelling approaches. LÄS MER
3. Vortices in turbulent curved pipe flow-rocking, rolling and pulsating motions
Sammanfattning : This thesis is motivated by the necessity to understand the flow structure of turbulent flows in bends encountered in many technical applications such as heat exchangers, nuclear reactors and internal combustion engines. Flows in bends are characterised by strong secondary motions in terms of counter-rotating vortices (Dean cells) set up by a centrifugal instability. LÄS MER
4. Cardiovascular modelling and ultrasound heart flow quantification : aortic flow and mitral regurgitation
Sammanfattning : The primary objective of this thesis was to model and simulate aortic flow and mitral regurgitation and to improve quantitative ultrasound measurements. The tools used were; theoretical analysis, computer simulation, model experiments, image analysis and clinical evaluation. LÄS MER
5. Cerebral blood flow and intracranial pulsatility studied with MRI : measurement, physiological and pathophysiological aspects
Sammanfattning : During each cardiac cycle pulsatile arterial blood inflates the vascular bed of the brain, forcing cerebrospinal fluid (CSF) and venous blood out of the cranium. Excessive arterial pulsatility may be part of a harmful mechanism causing cognitive decline among elderly. LÄS MER