[WiWo]

Hi Foamers,

I'm having a quite unexpected difficulty at the moment. For the equations in my current solver I need to determine a single scalar parameter from a non-linear 2nd order ordinary differential equation (initial value problem) at every time step. This parameter does not belong to any field - it's just a number (on per time step) I need to plug into the solver.
Now it doesn't seem to be straight forward to solve an ODE (in my case I want to get the radius of a micro bubble from the Rayleigh-Plesset equation) for just this one parameter in OpenFOAM. Does OpenFOAM offer the capabilities of solving such ODEs?

I'd appreciate any help or advice.

Best,
Wolfgang

[hjasak]

Yes, absolutely. We have the ODE library and ODE solvers. You can write your ODE as a derived class and use an ODE solver with it.

There is a relatively simple example in 1.5-dev under silvers/basic.

Good hunting,

Hrv

[WiWo]

Dear Prof. Jasak,

The hunt was very successful - thank you very much for referencing me to the sixDOFSolver!

I was able to adapt the ODE solver and its dedicated classes to fit my needs. It was then pretty straight forward to include this package into my overall solver - all done, verified and working :-)

I recognized that there is quite a significant difference between the ODESolver class of OF-1.5-dev and OF-1.6. My first attempt was actually to work with the ODETest case (applications/test) in OF-1.5-dev, but it was evidently designed to work with the 1.6(.x)-version of ODESolver. What is the reason for this discrepancy?

Thank you for your help!

Best regards,
Wolfgang

[Annier]

dear Wolfgang,
would you please guide me with the steps of solving the rayleigh plesset equation in OpenFOAM?
thanking you in advance.
annier