The models are obtained by simulating and simplifying the big curve at the arch of aorta and opposite curve of branching vessels . the original conditions of simulation calculating are the entrance velocities and the exit pressures . the boundary conditions are the wall non - slippery flow conditions and the symmetry conditions 它是基于主动脉弓处的大弯曲和分叉血管的反弯曲进行模拟简化,模拟计算的初始条件是进口速度和出口压力,边界条件是壁面无滑流条件和对称性条件。