Evaluating the mass flow rate m velocitys、 time interval dm dA Volume Control volume (CV) of matter Incremental area Control surface (CS) amount of mass A:area crossing dA during =pVn△t)dA the time interval△t Divided by△t ≥(N.a) Muti-streams instantaneous rate Integration over A of mass flow =pVn dA 防= PVn dA across dA 上究大学 March 26,2019 5 SHANGHAI JIAO TONG UNIVERSITYMarch 26, 2019 5 Evaluating the mass flow rate m velocity time interval : area Incremental area Divided by ∆t Integration over A Muti-streams