Implicit vs Explicit Solver for Wave propagation problems 2

[isponmo]

Dear Eng-tip users,

I have a question regarding the analysis of shock wave propagation problems in structures using FEM. Recently I was told that it is not possible to model shock wave propagation using implicit FEM schemes. The argument was that implicit schemes do not include this phenomena in their formulation... I am aware that explicit methods are generally recommended in cases like this cause they are far more efficient for problems of this nature. However, excluding computational efficiency, is there really any other reason preventing a shock wave problem from being solved with an implicit solver?

Thank you for your answers

 

[Mustaine3]

It is possible, but not efficient.

 

[isponmo]

Thanks for the answer!

 

[IceBreakerSours]

There is absolutely no theoretical limitation to solving a shock wave propagation problem using an implicit scheme. However, there are enormous practical limitations - which is why explicit schemes (I think it was von Neumann who invented first such scheme, but I am not sure) became popular in the first place.

Both implicit and explicit numerical schemes are just recipes to solve the underlying differential equation (which, supposedly, is a decent abstraction of the reality).

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[isponmo]

Thank you for your answer! It is clearer now.

 

[IceBreakerSours]

I should have been a little more careful with my strong statements above: There are some theoretical differences to the schemes as well. However, it is the practical considerations that make you go one or the other way. You will only learn those with experience but, if you can, coding a scheme will help tremendously. I strongly recommend reading the first four chapters from John Anderson's book on Computational Fluid Dynamics - The basics with applications.

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