The study presents a numerical parametric investigation of flow structures in channels with a longitudinal-radial profile zR = Const and a spherical dome at the base. The goal of the study was to examine the flow structures in these channels depending on the exponent N of the profile and the height of the dome, to determine the conditions that provide optimal centripetal swirling flow, analogous to blood flow in the heart chambers and major vessels. The investigation was conducted using a comparative analysis of flow structures in channel configurations zR = Const, carried out in two stages.
View Article and Find Full Text PDFStudy of swirling flows in channels corresponding to the static approximation of flow channels of the heart and major vessels with a longitudinal-radial profile zR = const and a concave streamlined surface at the beginning of the longitudinal coordinate has been carried out. A comparative analysis of the flow structure in channel configurations zR = const, where N = -1, 1, 2, 3, in the absence and presence of a concave surface was carried out. The numerical modeling was compared with the results of hydrodynamic experiments on the flow characteristics and the shape of the flow lines.
View Article and Find Full Text PDFA significant drawback of the rigid synthetic vascular prostheses used in the clinic is the mechanical mismatch between the implant and the prosthetic vessel. When placing prostheses with radial elasticity, in which this deficiency is compensated, the integration of the graft occurs more favorably, so that signs of cell differentiation appear in the prosthesis capsule, which contributes to the restoration of vascular tone and the possibility of vasomotor reactions. Aortic prostheses fabricated by electrospinning from a blend of copolymers of vinylidene fluoride with hexafluoropropylene (VDF/HFP) had a biomechanical behavior comparable to the native aorta.
View Article and Find Full Text PDFThis paper proposes a new approach to the quantitative analysis of the hydrodynamic structure of a blood flow in the flow channel running from the left atrium to the end of the aorta. This approach is based on the concept of the structural organization of tornado-like swirling jets in channels with a given geometric configuration. Considering the large amount of experimental data in our possession, it was shown that along the entire length of the flow channel, conditions exist for the generation and maintenance of a swirling structure of the jet throughout the entire cardiac cycle.
View Article and Find Full Text PDFThe materials used in the construction of implants contacting with blood should be resistant to thrombus formation. One of the stages of a thrombogenicity assessment of materials is to determine the number of platelets adhered to its surface during the exposure to flowing blood under ex viAvo conditions. The aim of this study was to develop a modified test for screening assessment of materials for their thrombogenicity in contact with native blood.
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