Discussion Forum

Hello. I am currently working on a project that is hoping to model the pressure and volume changes in a balloon in response to an input from a gas canister. I am relatively inexpierenced in COMSOL, have only been working with it for a few weeks.

My current questions: 1. I have done a little research and a previous COMSOL tutorial investigates the the response of a balloon being inflated by water https://www.comsol.com/model/water-balloon-inflation-56701 . I have downloaded the file and have the requisite modules, but am having trouble getting it to run. I have been getting a slew of errors, and would every time I attempt to fix a problem another pops up. The first of which is...

                        - Parameters: "fact","1"
          The following feature has encountered a problem:
           - Feature: Time-Dependent Solver 1 (sol1/t1)
           Failed to find consistent initial values.
           Last time step is not converged.

if I could get some help troubleshooting how to fully compute this, I would appreciate it.

2. Since I am working with a gas, there is a far greater emphasis on pressure, and how pressure can change the volume of the balloon. I am wondering what parameters I should investigate changing to represent the fact that we are working with a compressible fluid (air) rather than an incompressible fluid.

If you have any thoughts about how I could begin to model the balloon, or in how I could go about better answering the above questions, I would really appreciate it.

Thanks!