A two-input / two-output process involving simultaneous heating and liquid-level changes is illustrated in Fig. E6.20. Find the transfer function models and expressions for the gains and the time constant Ï„ for this process. What is the output response for a unit step change in Q for a unit step

change in w? Transfer function models for a somewhat similar process depicted in Fig. 6.13 are given in Eqs. 6-96 through 6-103. They can be compared with your results. For this exercise, T and h are the outputs and Q and w are the inputs.

. wi h lellllllld Heater Figure E6.20 W(s) (T - T\Vw TS + 1 W'ls) (T. - Tlw TS + 1 T'(s) TAs) TAs) w.lw 1/Ap H'(s) 1/Ap Figure 6.13 Block diagram of the MIMO thermal mixing system with variable liquid level.