Gas diffusion among bubbles and the DCS risk

TL;DR

This paper investigates gas diffusion among bubbles through experiments and simulations, showing how Ostwald ripening causes smaller bubbles to disappear and larger, potentially dangerous bubbles to grow, which may contribute to decompression sickness.

Contribution

It provides experimental and simulation evidence of Ostwald ripening in bubbles and suggests incorporating this effect into dive safety models like RGBM.

Findings

Smaller bubbles decrease over time while larger bubbles grow.

The mean bubble radius increases as the number of bubbles decreases.

Ostwald ripening may contribute to decompression sickness risk.

Abstract

We present some experimental and simulation results that reproduces the Ostwald ripening (gas diffusion among bubbles) for air bubbles in a liquid fluid. Concerning the experiment, there it is measured the time evolution of bubbles mean radius, number of bubbles and radius size distribution. One of the main results shows that, while the number of bubbles decreases in time the bubbles mean radius increases, hence, it follows that the smaller bubbles disappear whereas the -- potentially dangerous for the diver -- larger bubbles grow up. Consequently, this effect suggests a possible contribution of the Ostwald ripening to the decompression sickness, and if so, it should be pursued its implementation to the Reduced Gradient Bubble Model (RGBM) so as to build up dive tables and computer programs for further diving tests.