SINOPSIS

Traumatic aorta rupture accounts for a large number of fatalities in automobile crashes. Conditions corresponding to aorta rupture are difficult to reproduce experimentally in simulated collisions involving cadaveric surrogates. As a consequence, in situ observations of the dynamics of the flow inside the aorta, and of the dynamics of the aorta structure itself, under suddenly imposed large pressure loads are virtually non-existent. This paper communicates a combined experimental and numerical investigation of the problem. An experimental model of an aorta, devoid of secondary arteries, has been constructed from poly(dimethylsiloxane) or PDMS. The synthetic aorta (SA) is U-shaped, having nominal: inside diameter of 20 mm; wall thickness of 2 mm; radius of curvature of 27 mm; inlet and exit tangent lengths of 80 mm and 160 mm. The SA is filled with water and immersed in a tank with flat, transparent Plexiglass walls, also filled with water. Both ends of the SA are securely attached to fixed, vertical metal tubes. One tube is connected to an airtight overhead tank filled with water, and the other has a needle valve attached to its end. For the experiments communicated here, the needle valve is kept closed. The free surface of the water in the overhead tank is sequentially pressurized and depressurized very quickly to simulate the time-dependent pressure load associated with traumatic aorta rupture conditions. Observations of the flow in the SA via Particle Image Velocimetry (PIV), are obtained for a range of relevant dynamical conditions. The experimental observations are found to be in good agreement with corresponding numerical calculations obtained using ANSYS. This allows the use of the code to explore more realistic geometries and dynamical conditions relevant to traumatic aorta rupture and beyond the range of the experiments. The paper presents and discusses some of the most interesting findings.