A loop breaker is a special block that [b]breaks an algebraic loop[/b], by introducing a small (negligible) delay between its input and its output
An algebraic loop occurs when a term appears on both sides of an equation.
For instance, the flow balance around a flow combiner for e.g. the RAS recycle is something like:
[tt]Output = Input + Recycle[/tt]
but the recycle is a function of the output; and therefore:
[tt]Output = Input + f(Output)[/tt]
which can be simplified to / seen as:
[tt]O(t) = I(t) + O(t) + other terms(t)[/tt]
Such equation cannot be solved numerically.
By introducing a small delay, a loop breaker allows to rewrite the previous equation as:
[tt]O(t) = I(t) + O(t-dt) + other terms(t-dt)[/tt]
which can be solved numerically.