Step Responses: Linear vs. Nonlinear Models

In this section we will compare the step responses of the nonlinear model with those predicted by the linearized model. For comparison purposes, we will plot the physical variables.

For the linear model, which is in deviation variable form, we convert to physical values by realizing that

so, for the linear model

also

We will consider step changes of different magnitudes and different directions for this system.

• Small Increase in Jacket Temperature
• Large Increase in Jacket Flowrate
• Large Decrease in Jacket Flowrate
• Small Decrease in Jacket Flowrate