The fluid dynamics of the blood flow in the human aorta is of particular interest since provides significant insight into the regulation of vascular homeostasis and the localization of atherosclerosis. The fluid dynamics of human aorta exhibits complex flow phenomena such as flow separation due to the branching. Computational fluid dynamics may play a critical trole in understanding the complex fluid dynamics phenomena occurring inside the human aorta. In the present research numerical studies of blood flows in human aorta are carried out using the large-eddy simulation (LES) and improved delayed detached eddy simulation approaches.