two possible piping arrangements are shown in fig. 6-1.
in fig. 6-1a the outlet flow from tank 1 discharges directly into the atmosphere before spilling into tank 2, and the flow through R1 depents only on h1. the variation in h2 in tank 2 doesn't affect the transient reponse occurring in tank 1. this type of system is referred to as a noninteracting system. in contrast to this, the system shown in fig. 6-1b is said to be interacting because the flow through R1 now depends on the difference between h1 and h2. we will consider first the noninteracting system of fig. 6-1a