Integrator Error

Integrator error is the allowed error of the state variables of the hydromount during numerical integration. The state variables are the displacement (mm) and velocity (mm/s) of the effective fluid mass. The same numerical value, specified in the Integrator Error text box, is used for both states.

The numerical integration is done with a 4th-order Runge-Kutta method. The time-step size is automatically varied during the integration in accord with the value of the error tolerance. The error is calculated based on two means of computing the next values of the state variables: one explicit and the other implicit. If the results of the explicit and implicit computations differ by more than the error tolerance for either state variable, then the time-step size is decreased and the integrator tries again. If the error is very small compared to the error tolerance for both state variables, then the time-step size is increased for the next time interval.