3D flow topology behind an aortic valve bioprosthesis

We have developed a hydraulic flow loop to replicate the flow conditions in the ascending aorta. The setup features a measurement cell with a silicone phantom of the aortic root. We use a refraction index matched fluid and multi-view camera setup for recording of the pulsatile fluid flow within the silicone phantom. The fluid is seeded with fluorescent particles. Tomographic particle image velocimetry is applied to measure the three-dimensional instantaneous velocity field at specific phases of the pulse. We present results of the instantaneous and the phase averaged velocity field past an aortic bioprosthesis. Based on a Reynolds decomposition of the velocity field the root-mean-square velocity fluctuation can be computed, revealing regions with increased turbulent shear stresses. In general a specific flow topology that can be related to the features of the valve is observed. With this paper we aim to demonstrate the great potential of the presented method to investigate the performance of the valve.