A lumped model for long bone behavior based on poroelastic deformation and Darcy flow.

The present paper provides a simplified model for compact bone behavior by accounting for bone fluid flow coupled to the elasticity of the porous structure. The lumped model considers the bone material as a layered poroelastic structure and predicts normal pressure versus displacement, i.e, a stress-strain curve.

Comparison between a generalized Newtonian model and a network-type multiscale model for hemodynamic behavior in the aortic arch: Validation with 4D MRI data for a case study.

Blood is a complex fluid in which the presence of the various constituents leads to significant changes in its rheological properties. Thus, an appropriate non-Newtonian model is advisable; and we choose a Modified version of the rheological model of Phan-Thien and Tanner (MPTT). The different parameters of this model, derived from the rheology of polymers, allow characterization of the non-Newtonian nature of blood, taking into account the behavior of red blood cells in plasma.

Numerical study of purely viscous non-Newtonian flow in an abdominal aortic aneurysm.

It is well known that blood has non-Newtonian properties, but it is generally accepted that blood behaves as a Newtonian fluid at shear rates above 100 s-1. However, in transient conditions, there are times and locations where the shear rate is well below 100 s-1, and it is reasonable to infer that non-Newtonian effects could become important. In this study, purely viscous non-Newtonian (generalized Newtonian) properties of blood are incorporated into the simulation-based framework for cardiovascular surgery planning developed by Taylor et al.

The Phan-Thien and Tanner model applied to thin film spherical coordinates: applications for lubrication of hip joint replacement.

The Phan-Thien and Tanner (PTT) model is one of the most widely used rheological models. It can properly describe the common characteristics of viscoelastic non-Newtonian fluids. There is evidence that synovial fluid in human joints, which also lubricates artificial joints, is viscoelastic.

3-D model of a total hip replacement in vivo providing hydrodynamic pressure and film thickness for walking and bicycling.

Formulation of a 3-D lubrication simulation of a total hip replacement in vivo is presented using a finite difference approach. The goal is to determine if hydrodynamic lubrication is taking place, how thick the joint fluid film is and over what percentage of two gait cycles, (walking and bicycling), the hydrodynamic lubricating action is occurring, if at all. The assumption of rigid surfaces is made, which is conservative in the sense that pure hydrodynamic lubrication is well known to predict thinner films than elasto-hydrodynamic lubrication (EHL) for the same loading.