Aortic valve diseases are among the leading causes of death worldwide, and severe aortic stenosis requires valve replacement. Two approaches are available: conventional surgery via thoracotomy or transcatheter aortic valve implantation (TAVI). The coaxial positioning of the prosthetic valve relative to the aortic annulus affects transvalvular blood flow and may contribute to aortic remodeling, including aneurysms, dissection, and atherosclerosis. This study numerically evaluated the impact of coaxial valve positioning on turbulent flow in the ascending aorta and aortic arch using a patient-specific model from TAVI and the k-w SST turbulence model. Relationships between valve positions and regions of high turbulent intensity were identified. The analysis suggests that directing the prosthesis 4° toward the left aortic wall minimizes turbulence, reducing mean turbulent kinetic energy and turbulent shear stress by 40% and 65%, respectively, compared to the reference (0° inclination).