THE EFFECTS OF VISCOSITY ON THE BEHAVIOR OF BUBBLES IN VISCOUS-LIQUIDS

Numerical algorithms were developed to solve the basic equations descr ibing growth or dissolution of bubbles in viscous liquids both for iso thermal behaviour or variable temperature. Growth and dissolution of g as bubbles in viscous liquids cause changes in concentration inside th e bubble and in the liquid at equilibrium with the gas phase, and thes e changes also affect the dynamics of bubble behaviour. Simple criteri a are provided to assess when the role of viscosity is significant, du e to slow viscous relaxation. The growth or dissolution of carbon diox ide bubbles and oxygen bubbles in soda-lime-silicate glasses has been chosen to demonstrate the main features of isothermal bubble behaviour and the changes that occur as glass samples are cooled from fining te mperature to room temperature at several cooling rates. The predicted changes in size and concentration inside the bubbles stop at about 100 -150-degrees-C above the glass annealing temperature for typical cooli ng rates.