抄録
This study has been performed to evaluate a relationship between drag coefficient and defect area rate of an orifice. The drag coefficient is an index for functional estimation of the defect area rate of the orifice, which can be utilized to evaluate the degree of aortic regurgitation and stenosis. Firstly, we defined the drag coefficient for both of steady and pulsatile flows. Secondly, we have compared the experimental results of the drag coefficient with theoritical one in steady and pulsatile flows. In steady flow, the both results approximately coincide with eachother. In pulsatile flow, they are almost same only at high Reynolds number region. So we consider the defect area rate can be estimated from the drag coefficient.
