[M-GI35] Computational sciences on the universe, galaxies, stars, planets, and their environments

[MGI35-P03] Modificartion of SPH for the simulation of an icy moon with internal ocean

*keiya murashima¹, Natsuki Hosono², Takayuki Saitoh², Takanori Sasaki¹ (1.Kyoto University, 2.Kobe University)

Keywords:SPH, icy moon

There is evidence of subsurface ocean in some icy moons, such as plumes of vapor of Europa and Enceladus.
Since liquid water would be essential for the origin of life, it is important to understand the development of subsurface ocean, especially the temperature distribution/evolution inside the icy moons.

Thus, we aim to simulate the development of a subsurface ocean of an icy moon by 3-dimensional numerical fluid calculations using Smoothed Particle Hydrodynamics (SPH) method.
We added viscosity, conductive heat transfer and radiative cooling terms to the standard SPH method.
However, we found two problems in calculating the rigid body rotation by the scheme.
First, the conventional formulation of viscosity term unphysically stops the rotation of the rigid body.
Second, the standard SPH makes an artificial internal energy partitioning that causes SPH particles’ artificial layers.
In order to address these issues, we applied two modifications; one is the improved SPH scheme, viz., density-independent SPH (DISPH) and another is non-pair-wise viscosity.
We found that these modifications work well for the rigid body rotations.
We conclude that our modification is favourable for the simulation of the rigid body rotation.