Numerical computations of rectified diffusion in nonlinear bubble oscillations

A previous approach to the problem of rectified diffusion in bubble oscillations [J. Acoust. Soc. Am. 37, 493–503 (1965)] has been applied to the recent nonlinear bubble dynamics theory of Prosperetti et al. [J. Acoust. Soc. Am. 83, 502–514 (1988)]. A numerical solution is given that calculates growth rates and pressure amplitude thresholds for rectified diffusion and allows modification of the radial oscillations of bubbles due to gas diffusion. The results of the new approach are compared to other rectified diffusion theories, and differences in radial bubble oscillations with and without diffusion are examined. Some experimental measurements of rectified diffusion are also compared to the theoretical results. [Work supported by NIH.]