·dS V·dS=0 Controf surface Control volume y =p2242 x Fig 10.5 Finite control volume for quasi-one-dimensional flow 连续方程: pV ds=0 P1141=P22 (10.1)Fig.10.5 Finite control volume for quasi-one-dimensional flow •连续方程: 1 u1 A1 = 2 u2 A2 (10.1)   = S V dS 0   V •dS = 0 1 1 1 1 u A A   = − •  V d S 2 2 2 2 u A A   = •  V d S