Developing the mass rate balance Dashed line defines the control volume boundary mi nev(①) nev(t+△) Region i LRegion e m →m; Time t Time t+△t me→ Study: the fixed quantity of matter m as time elapses: mev(t)+mi=mev(t At)+me mev(t At)-moy(t)=mi-me me(t+△t)-nev(t) mi me △t △t△t 上游充通大 March 26,2019 3 SHANGHAI JIAO TONG UNIVERSITYMarch 26, 2019 3 Developing the mass rate balance Study: the fixed quantity of matter m as time elapses: mi me m