Abstract
A new method for measuring dynamic viscoelasticity of highly viscous fluids was developed. The strain-stress relation was obtained from the motion of a bubble subjected to pressure fluctuation. A set of basic equations was derived, which represented the relation between frequency response of bubble motion and dynamic viscoelasticity. A pilot apparatus was constructed to perform a preliminary test, in which commercial silicone oil (kinematic viscosity 1m^2/s) was used as a test material. The dynamic viscoelasticity for the silicone oil was successfully obtained up to 200Hz, which is impossible to obtain by conventional rotating rheometers.
