Numerical predictions of blood flow patterns and hemodynamic stresses in Abdominal Aortic Aneurysms (AAAs) are performed in a two-aneurysm, axisymmetric, rigid wall model using the spectral element method. Physiologically realistic aortic blood flow is simulated under pulsatile conditions for the range of time-averaged Reynolds numbers 50< or =Re(m)< or =300, corresponding to a range of peak Re...

In continuing the investigation of AAA hemodynamics, unsteady flow-induced stresses are presented for pulsatile blood flow through the double-aneurysm model described in Part I. Physiologically realistic aortic blood flow is simulated under pulsatile conditions for the range of time-average Reynolds numbers 50< or =Re(m) < or =300. Hemodynamic disturbance is evaluated for a modified set of indi...

The wall-normal gradient of Reynolds shear stress, denoted ∂T+/∂y+, may be thought of as a momentum source or sink term (depending on its sign). This quantity represents a critical driver of the dynamics of wall-turbulence that give rise to the mean velocity distribution. While there have been a number of studies concerning the statistics of ∂T+/∂y+, there remains much to discover regarding the...

The Reynolds stress induced by anisotropically forcing an unbounded Couette flow, with uniform shear γ, on a β-plane, is calculated in conjunction with the eddy diffusivity of a co-evolving passive tracer. The flow is damped by linear drag on a time scale μ. The stochastic forcing is white-noise in time and its spatial anisotropy is controlled by a parameter α, that characterizes whether eddies...

We consider here pulsatile flow in circular tubes of varying cross-section with permeable walls. The fluid exchange across the wall is accounted for by prescribing the normal velocity of the fluid at the wall. A perturbation analysis has been carried out for low Reynolds number flows and for small amplitudes of oscillation. It has been observed that the magnitude of the wall shear stress and th...

The advent of microelectromechanical systems (MEMS) sensors has enabled real-time wall shear stress (WSS) measurements with high spatial and temporal resolution in a 3-D bifurcation model. To optimize intravascular shear stress assessment, we evaluated the feasibility of catheter/coaxial wire-based MEMS sensors in the abdominal aorta of the New Zealand white (NZW) rabbits. Theoretical and compu...

Abstract---The steady flow of a second order fluid through constricted tube with slip velocity at wall is modeled and analyzed theoretically. The governing equations are simplified by implying no slip in radial direction. Based on Karman Pohlhausen procedure polynomial solution for axial velocity profile is presented. Expressions for pressure gradient, shear stress, separation and reattachment ...

Simultaneous velocity field and optical distortions along the wall-normal direction were performed in a subsonic boundary layer. Comparison between wavefronts and the ones predicted using instantaneous Strong Reynolds Analogy had shown that instantaneous SRA is valid most of the time. Conditional velocity analysis had shown that positive OPD distortions are created by predominantly ejection-typ...