Calculating Artificial Viscosity
Is there any analytical formula to calculate artificial viscosity from kinematic viscosity and density ?
Some papers of Colagrossi et al defines a relationship... However that formula is only valid for some problems such as wave tanks (where a value of alpha=0.01 has been shown to provide good results), but it is not valid for dam-breaks or sloshing problems using DualSPHysics since alpha will vary with particle resolution.
. I want to simulate a Molten Metal Flow through a casting Mould and all i am getting is the artificial viscosity of water.
Then you will have to find some physical experiments of these cases, use the artificial viscosity values until you hit the same experimental results. Then you can use this artificial viscosity you've found for your own case. Note that this is still an approximation, since you have not conducted an experiment your self (?) - if you have you can use that instead.
As a final note, artificial viscosity, is not a property any fluid has - it should be understood as a tuning factor, which is able to stabilize SPH simulation without enormous numbers of particles and get results comparable to the experiments which have been conducted.
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