Is particle i included in the summation?
Hi
I found someone (https://pmocz.github.io/manuscripts/pmocz_sph.pdf) writing the momentum equation as:
In this case it does not m atter since ri - ri = 0, and the gradient kernel will produce 0, but in non gradient terms this would matter. Should the summation not include particle i?
Kind regards
Comments
Hi,
For most SPH kernels which are symmetric (even) functions (i.e. Wendland kernels) the gradient is zero (odd function) for i-i interaction. For the kernel itself (even) the i-i interaction is has a finite non-zero value and should be included in the summation.
do a quick check/exercise, use the Wendland kernel with rij=0 and calculate the kernel and its gradient.
Thanks,
George
Hi !
Thank you very much, it makes sense now!
Kind regards