Zusammenfassung
A widespread model of thermal ink-jet actuation prescribes the
pressure of the expanding bubble as a rapidly decreasing function of
time, this being taken as a finite version of a Dirac impulse with
only the integral with respect to time mattering. Here it is shown
that the impulse is actually easier to treat numerically than the
bounded approximation and an implementation in OpenFOAM is described;
however, solutions so obtained reveal that the flow does depend on the
timescale over which the pressure is applied, i.e. on first and higher
moments of the pressure function. An asymptotic expansion of a lumped
linear model is derived which predicts the dependence of the induced
flow on these moments for an arbitrarily shaped pressure pulse.
Nutzer