Wall velocity for Eulerian SPH is not correct.

[Bo-Zhang1995]

SPHinXsys/src/shared/particle_dynamics/fluid_dynamics/eulerian_fluid_dynamics/eulerian_fluid_integration.hpp

Line 141 in c2c30ec

Vecd vel_in_wall = -state_i.vel_;

The wall speed is not correct for the Eulerian SPH when it involves the wall.
For example, if the wall has a speed, like lip driven cavity, the wall speed should not be the negative speed of the particle i.
It should be like the LG sph, vel_j = 2 * vel_wall - v_i.

[Xiangyu-Hu]

@ZhentongWang could you have a look at it? Thanks.

[ZhentongWang]

SPHinXsys/src/shared/particle_dynamics/fluid_dynamics/eulerian_fluid_dynamics/eulerian_fluid_integration.hpp

Line 141 in c2c30ec

Vecd vel_in_wall = -state_i.vel_;

The wall speed is not correct for the Eulerian SPH when it involves the wall. For example, if the wall has a speed, like lip driven cavity, the wall speed should not be the negative speed of the particle i. It should be like the LG sph, vel_j = 2 * vel_wall - v_i.

Yes, the velocity in wall as vel_in_wall = 2 * vel_ave - v_i. I was just considering the static wall boundary condition for Eulerian cases in current, so the vel_ave is always zero. When I simulate the lid-driven cavity in Eulerian SPH method, I also use the equation vel_in_wall = 2 * vel_ave - v_i but have not changed that equation in the current master. Therefore, the general equation for velocity in wall boundary is vel_j = 2 * vel_wall - v_i.

[Xiangyu-Hu]

@ZhentongWang So, should we change the code on this?

[ZhentongWang]

@ZhentongWang So, should we change the code on this?

yes, I will change the code and use the more general equation for wall velocity soon.

[Xiangyu-Hu]

@ZhentongWang So, should we change the code on this?

yes, I will change the code and use the more general equation for wall velocity soon.

@ZhentongWang So, should we change the code on this?

yes, I will change the code and use the more general equation for wall velocity soon.

@ZhentongWang So, should we change the code on this?

yes, I will change the code and use the more general equation for wall velocity soon.

@ZhentongWang Is this done already?

[ZhentongWang]

@ZhentongWang So, should we change the code on this?

yes, I will change the code and use the more general equation for wall velocity soon.

@ZhentongWang So, should we change the code on this?

yes, I will change the code and use the more general equation for wall velocity soon.

@ZhentongWang So, should we change the code on this?

yes, I will change the code and use the more general equation for wall velocity soon.

@ZhentongWang Is this done already?

I have created a pull request to have it fixed.
i.e. Vecd vel_in_wall = 2.0 * vel_ave_k[index_j] - state_i.vel_.

[Xiangyu-Hu]

@ZhentongWang Could link this issue to the branch for fixing? So that, this issue will close automatically after the pull request is done.