Approximating fluid response with Helmholtz resonance

Sometimes, simple tools are very useful guides to understand the behaviour of complex systems. In this example, we're going to explore aspects of the mechanical response of a fluid in an ink jet nozzle by asuming that it behaves in a manner similar to a Helmholtz resonator. In the image below, an approximation of an inkjet nozzle is shown on the left, containing a good, bright, magenta ink at rest! We're going to perturb it by putting a square wave displacement, lasting 5 microseconds, onto the piezo element and then watch how the ink moves. The mechanical approximation to the ink in the nozzle is shown on the right by a 2 degree of freedom spring and damper system. The mass m₁ corresponds to the ink in the throttle and the mass m₂ corresponds to the ink in the nozzle.

There are a number of variables that you, dear user, can alter to see how the response differs! The length and radius of the throttle (L₁ and R₁, respectively) and of the nozzle (L₂ and R₂) You can also alter the fluid's viscosity and density. The boxes below all contain some good initial values to start with - but see for yourself how changing them alters the mechanical response of the system!
Here are some ideas as to what to change so you can get a mental model of how this system works:

(1) What parameters change the resonant frequencies of the system and how?
(2) What parameters change how much the fluid oscillates?
(3) What do the different resonant modes mean physically?

Throttle length (microns):
Throttle radius (microns):
Nozzle length (microns):
Nozzle radius (microns):
Fluid viscosity (mPa s):
Fluid density (kg m³):

Please just click once and wait for a few seconds whilst the magic happens!