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dc-arri1 created page: gravity tests authored by Stefan Arridge's avatar Stefan Arridge
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gravity-tests.md
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...@@ -8,4 +8,21 @@ Snapshots taken every 0.1 unit times, time unit chosen so that G = 1. ...@@ -8,4 +8,21 @@ Snapshots taken every 0.1 unit times, time unit chosen so that G = 1.
Apply a drift in the plane of the orbit. Plots show absolute fractional change in energy for drift speed = 0 , 1 , 2 , 3 unit velocities (circular velocity is 1/root(2)). Apply a drift in the plane of the orbit. Plots show absolute fractional change in energy for drift speed = 0 , 1 , 2 , 3 unit velocities (circular velocity is 1/root(2)).
Box of size 12cm. Things go crazy when the particles drift off the edge of the box.![energy_change_l_1_drift_speed_0](/uploads/5707ac2534646767c3d35dcfb586bf49/energy_change_l_1_drift_speed_0.png)![energy_change_l_1_drift_speed_1](/uploads/fa522d5256cc000ae8847afac9075e8c/energy_change_l_1_drift_speed_1.png)![energy_change_l_1_drift_speed_2](/uploads/ce4a4ced1d4a1c7a7bb1ebd9703c9916/energy_change_l_1_drift_speed_2.png)![energy_change_l_1_drift_speed_3](/uploads/ea22369a82bdea43e0ed9d6b223e64c8/energy_change_l_1_drift_speed_3.png) Box of size 12cm. Things go crazy when the particles drift off the edge of the box.!
\ No newline at end of file [energy_change_l_1_drift_speed_0](/uploads/5707ac2534646767c3d35dcfb586bf4/energy_change_l_1_drift_speed_0.png)![energy_change_l_1_drift_speed_1](/uploads/fa522d5256cc000ae8847afac9075e8c/energy_change_l_1_drift_speed_1.png)![energy_change_l_1_drift_speed_2](/uploads/ce4a4ced1d4a1c7a7bb1ebd9703c9916/energy_change_l_1_drift_speed_2.png)![energy_change_l_1_drift_speed_3](/uploads/ea22369a82bdea43e0ed9d6b223e64c8/energy_change_l_1_drift_speed_3.png)
A line of particles with a total mass of 1 solar mass is frozen in place. Another particle is put into a circular orbit at 1AU in a plane normal to the line, with the plane bisecting the line. Below I show the change in kinetic, potential and total energy, which should all stay the same.
eta = 0.01 and epsilon = 0.01
First plot is simply the two-body problem again
![energy_change_particle_line_n_1](/uploads/fe43a78ecbd332a16029d3713500c2df/energy_change_particle_line_n_1.png)
![energy_change_particle_line_n_2](/uploads/83e384455602561fd28646a93243aadd/energy_change_particle_line_n_2.png)
![energy_change_particle_line_n_100](/uploads/ee60c593a40495c11ec30d3502cebda1/energy_change_particle_line_n_100.png)
Here I show the effect of decreasing eta on conservation of total energy (epsilon = 0.01)
![line_of_10_particles_eta_test](/uploads/32397720099e5df21c60e6e6f2b67860/line_of_10_particles_eta_test.png)
Same test but instead I put the orbiting particle in the same plane as the line
![line_of_10_particles_plane_eta_test](/uploads/efce48af686059fb8b702d8ccffca39d/line_of_10_particles_plane_eta_test.png)