V·dS=0 Controler Control volume y A1 (pv·dSu=pu1(-A1)1 PV·dSm=p2(+A2) A1 2 f11 Fig 10.5 Finite control volume for quasi-one-dimensional flowFig.10.5 Finite control volume for quasi-one-dimensional flow 1 2 1 1 1 1 1 ( ) ( ) 1 u A u u A u A    = − • = −  V d S 2 2 2 2 2 2 2 ( ) ( ) 2 u A u u A u A    = • = +  V d S ( )u的积分: V •dS = 0 S  V •d S