Demonstrate the Kozai Mechanism

[infringement153]

Does anybody have a ubox/xml file that uses the Kozai mechanism to cause a moon to crash into a planet?  Or, if not, does anybody know how to create the sim myself?  Whenever I try to use the Kozai mechanism to cause crashing by putting a moon into polar orbit, all I get is a gentle oscillation of eccentricity/inclination, not an impact.

Something similar to the earth/moon simulation here.
http://www.orbitsimulator.com/gravity/articles/kozai.html

Thank you.

[Laura]

Do you have the planet orbiting a star in the experiment? I believe it's important that the planet is moving for this effect to show up.

[infringement153]

Yes.  I took the normal "solar system" sim, and added a polar-orbiting moon to earth.

[APODman]

Does anybody have a ubox/xml file that uses the Kozai mechanism to cause a moon to crash into a planet?  Or, if not, does anybody know how to create the sim myself?  Whenever I try to use the Kozai mechanism to cause crashing by putting a moon into polar orbit, all I get is a gentle oscillation of eccentricity/inclination, not an impact.

Something similar to the earth/moon simulation here.
http://www.orbitsimulator.com/gravity/articles/kozai.html

Thank you.

You try convert the kozai simulation file of Gravity Simulator to Universe Sandbox simulation file ?

[ ]´s

[atomic7732]

Or simulate the HD 80606 (Struve 1374?) system.

[Dan Dixon]

Here's the converted XML file of the kozai.gsim simulation.

Gravity Simulator's latest beta version has a Universe Sandbox XML format exporter. I used that to create this file. Although I think there's a bug in the exporter and you need to set your timestep to 1 before you export.

[APODman]

Here's the converted XML file of the kozai.gsim simulation.

Gravity Simulator's latest beta version has a Universe Sandbox XML format exporter. I used that to create this file. Although I think there's a bug in the exporter and you need to set your timestep to 1 before you export.

It works, the Kozai mechanism is demonstrated but an impact don´t occurs.

[ ]´s

[frankdepinte]

Has the timestep been checked during the simulation ? if to big the collision doesn't happen

[Laura]

Experiment: Demonstrate Kozai Mechanism

Initial conditions: The kozai.xml file provided by Dan.

Parameters: RK4 accuracy, Timestep 30 minutes (except at the very end, where it was reduced to more accurately check for collision).

Observations: Orbit of moon oscillates around inclination 90, tending more towards positive growth rather than negative. During periods of greatest positive deviation from 90, eccentricity grows markedly, while it comes to a standstill at periods of greatest negative deviation. With each such cycle, the effect becomes more pronounced, and the deviation in inclination greater. Eccentricity never reduces; it only grows exponentially, and as it does so, deviation from inclination 90 becomes increasingly pronounced.
Collision took place near the end of the 5th year, with inclination exceeding 110 degrees, and eccentricity somewhere between 0.99 and 1. Timestep was reduced to 5 minutes for the last few cycles.
Regrettably, I have no visual data for that final year which exhibited the greatest changes - I should not have stuck so doggedly to the policy of taking one picture at the end of each year.
Below is an orbital plot covering the time from the beginning of the simulation to the end of the 4th. year. Each year is color coded to make it easier to see the age of the data.

Conclusion: The Kozai Mechanism can be demonstrated with US2