DEVELOPMENT AND INTERACTIONS OF 2 INERT-GAS BUBBLES DURING DECOMPRESSION

A mathematical model has been developed to simulate the evolution of t wo inert gas bubbles in tissue. This is useful for understanding the d ynamics of bubbles that presumably arise during decompression. It is a ssumed that they are spherical and that the tissue volume surrounding them is infinite. The total pressure in each bubble is determined by t he barometric and metabolic gas pressures as well as the pressure due to surface tension. Bipolar coordinates are employed to determine the inert gas pressure distribution. Two coupled governing equations for b ubble radii are then derived and solved numerically. The results demon strate how bubble evolution is affected by the distance between bubble s and the initial bubble radii. The existence time and bubble surface flux of two equal-sized bubbles are calculated and compared with those of a single gas bubble model. The results indicate that when two bubb les are very close, it takes 20% more time for two bubbles to dissolve than for a single one, and the total surface flux of two bubbles is n early 20% less than twice of a single bubble. When the center-to-cente r distance is 10 times of bubble radius, the effect of bubble interact ion on bubble existence time and surface nux are about 6 and 9% change s, respectively. We conclude that if bubbles are not too small, the in teractions among bubbles should be included in inert gas bubble models predicting bubble evolution.