These equations were made using five major assumptions, with four of them being common to all the equations:
# The bubble remains spherical
# The bubble contents obey the ideal gas law
# The internal pressure remains uniform throughout the bubble
# No evaporation or condensation occurs inside the bubble
The fifth assumption, which changes between each formulation, pertains to the thermodynamic behavior of the liquid surrounding the bubble. These assumptions severely limit the models when the pulsations are large and the wall velocities reach the speed of sound.