https://blog.gongquiz.com/2020/10/07/%eb%8b%a4%ec%9d%8c-%ec%a4%91-%ec%9d%b4%ec%83%81%ec%9c%a0%ec%b2%b4ideal-fluid%ec%97%90-%eb%8c%80%ed%95%9c-%ec%84%a4%eb%aa%85%ec%9c%bc%eb%a1%9c-%ea%b0%80%ec%9e%a5-%ec%a0%81%ed%95%a9%ed%95%9c-%ea%b2%83/