Cardiovascular diseases are the main causes of death worldwide. Pathologies in the aorta artery are especially dangerous, since it is the largest vessel in the human body, large volumes of blood flow through it. The objective of this study is to determine the flow inside an aorta, during the systole period, of a specific patient, after a surgical procedure of TAVI implantation. Often, the aortic valve is modeled as a simple orifice and in this study, the impact of a more realistic representation of the valve is investigated, modeling the leaflets and considering their geometric variation during the systolic period. The impact of valve simplification by an orifice, with the elimination of leaflets is discussed. Then, five moments of time during the systole period are analyzed, when not only the flow and pressure at the aortic input varies, but also the opening of the valve and the height of the leaflets changes. These solutions were obtained in a simplified way, considering that the transient can be represented by a succession of permanent regimes for each configuration. The flow regime was modeled as turbulent and the k-w STT model was selected. The hemodynamic patterns of blood flow within the aorta were determined with the Fluent software. The impact of the valve leaflets in the field of velocity, pressure and turbulent quantities was evaluated, with special focus on the aortic surface stress. The interpretation of the results revealed that the approximation of the aortic valve as a circular orifice is plausible approach, and the addition of the valves leaflets does not generate significant changes in the flow patterns.