  Immersed mechanical resonators are well suited for probing the properties of
fluids, since the surrounding environment influences the resonant
characteristics of such oscillators in several ways. Quartz tuning forks have
gained much popularity in recent years as the resonators of choice for studies
of liquid helium. They have many superior properties when compared to other
oscillating bodies conventionally used for this purpose, such as vibrating
wires. However, the intricate geometry of a tuning fork represents a challenge
for analyzing their behavior in a fluid environment - analytical approaches do
not carry very far. In this article the characteristics of immersed quartz
tuning fork resonators are studied by numerical simulations. We account for the
compressibility of the medium, that is acoustic phenomena, and neglect
viscosity, with the aim to realisticallymodel the oscillator response in
superfluid helium. The significance of different tuning fork shapes is studied.
Acoustic emission in infinite medium and acoustic resonances in confined
volumes are investigated. The results can aid in choosing a quartz tuning fork
with suitable properties for experiments, as well as interpreting measured
data.
