Cardiovascular diseases, particularly atherosclerosis, remain the leading cause of death worldwide. This study employs computational fluid dynamics (CFD) coupled with cardiac computed tomography (CT) to simulate coronary blood flow in both idealized and patient-specific models. Different sizes of atherosclerotic plaques were introduced near bifurcations and curved regions to investigate their hemodynamic effects. The simulations provided non-invasive assessments of key parameters, including blood velocity, wall shear stress (WSS), relative pressure difference, and fractional flow reserve...