Production of gas bubbles in fluids by tribonucleation

¹ Biophysics Branch, Physiology Division, US Air Force School of Aerospace Medicine (AFSC), Brooks Air Force Base, Texas 78235

This report describes a mechanism, called tribonucleation, for producing gas nuclei by making and breaking contact between solid bodies which are immersed in liquid. A metal ball was rolled inside a glass tube filled with liquid which contains dissolved gas. Formed nuclei may grow to visible bubbles depending on the dissolved gas concentration and pressure applied to the liquid. Unlike other possible mechanisms for forming bubbles, tribonucleation is capable of producing nuclei under relatively mild experimental conditions, such as may be encountered in vivo. The experiments show that viscosity and velocity of separation of surfaces are important determinants of whether or not nuclei will form.

Submitted on August 20, 1969