Technical Discussion on VPM

Robert C. Helling helling at
Sun Mar 9 10:04:38 PDT 2014

On 09 Mar 2014, at 09:55, Gopichand Paturi <gopichandpaturi at> wrote:


> So, as I went through the permeability theory I learnt that, solutions have inherently microbubbles called Nuclei of size[0.01MicroMeter-1Micrometer].
> that are at unstable equlibrium in every solution.

Hmm. That are two orders of magnitude for the radius which translates to six orders of magnitude for the volume. I would call that quite a range of values. IF we take only one radius as initial value, which one would you suggest to represent this range?

> I think we need to initialize bubble of each inert gas with the specific size in a compartment depending on the mixture of the gas. That means I think we need to put 3 bubbles in each compartment if it is a Trimix.

I doubt that. It is clearly unphysical to assume that there are bubbles that contain only He and other only N2. In reality any bubble will contain a mixture of all gases. Furthermore, oxygen plays no role in decompression calculations due to its special role in the body where it is almost entirely bound to haemoglobin rather than being dissolved in blood.

What about yesterday’s questions regarding the time evolution of the bubble size?


Robert C. Helling     Elite Master Course Theoretical and Mathematical Physics  
                      Scientific Coordinator                                   
                      Ludwig Maximilians Universitaet Muenchen, Dept. Physik    
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