In vivo 4-dimensional flow MRI of the descending thoracic aorta revealed tangential wall velocities of 30–80% of the mean luminal velocity, challenging the classical no-slip boundary condition.
Observational (n=7)
Does blood flow exhibit macroscopic slip behavior at the aortic wall in vivo compared to the classical no-slip assumption?
In vivo 4D flow MRI demonstrates macroscopic blood flow slippage at the aortic wall, challenging the foundational no-slip boundary condition assumption in cardiovascular fluid dynamics.
The assumption that blood adheres to vessel walls with zero tangential velocity component, the so-called “no-slip” boundary condition, is a foundational premise of cardiovascular fluid dynamics. Whether the no-slip condition holds in vivo, however, remains unknown. Seven healthy adult volunteers underwent cardiovascular magnetic resonance imaging. Using 4-dimensional flow magnetic resonance imaging of the descending thoracic aorta and modeling blood as a Navier–Stokes fluid, near-wall blood velocities were quantified, and wall shear stress was calculated based on the measured velocity fields. Within the Navier–Stokes data-assimilation framework, tangential wall velocities of approximately 30–80% of the mean luminal velocity were consistently obtained. These results provide evidence for effective macroscopic slip behavior at the aortic wall in vivo. Consequently, wall shear stresses were substantially reduced compared with values obtained under the assumption of no-slip. This finding challenges the universal use of the classical no-slip boundary condition in macroscopic cardiovascular flow modeling and directly affects key blood flow characteristics such as pressure drop, vorticity, wall shear stress, and energy dissipation, which play important roles in both normal and disease-state cardiovascular conditions.
Jarolímová et al. (Tue,) conducted a observational in Healthy (n=7). 4-dimensional flow magnetic resonance imaging vs. Classical no-slip boundary condition assumption was evaluated on Tangential wall velocities and wall shear stress. In vivo 4-dimensional flow MRI of the descending thoracic aorta revealed tangential wall velocities of 30–80% of the mean luminal velocity, challenging the classical no-slip boundary condition.