Accretion disk model: Hydrodynamical or collisional N-Body?

[farIR]

Right now I'm playing around with DynGen, a routine which uses a hydrodynamical approach to simulate a dusty torus and a planet orbiting within it. It uses laroche limits, etc. to model what happens with the resonant trapping as this planet orbits - the parameters are planet mass and disk viscosity, nothing more.

the planet feels the disk and the disk feels the planet, but the disk does not feel itself, ie it does not self-gravitate.

Anyway, the routine isn't N-body collisional, ie the disk is like a fluid and it doesn't stick to itself. I'm a little worried about this as one would think an actual accretion disk would be an intermediate between a truly collisional model and this hydrodynamical approach. My colleagues really aren't helping much, so I thought I'd try to field the question here.

Anyone have any thoughts? I know this is a rather bizarre, open ended question, but I thought I'd try.

 

[AndyW]

Hello, thank you for sharing your work on DynGen. It sounds like a very interesting and complex simulation. I can understand your concern about the lack of self-gravity in the disk. While it may not be a perfect representation of a real accretion disk, it's important to remember that simulations are always simplified versions of reality. It's impossible to include every single factor and variable in a simulation, so we have to make educated choices about what to include and what to leave out.

In this case, it seems like the hydrodynamical approach is a good starting point for understanding the dynamics of a dusty torus and a planet orbiting within it. It allows you to explore the effects of planet mass and disk viscosity, which are important factors in the overall behavior of the system.

However, if you want to incorporate self-gravity into your simulation, there are a few options you could consider. One possibility is to include a simplified form of self-gravity, such as a gravitational force between the particles in the disk. This would add another layer of complexity to the simulation, but it may also provide more realistic results.

Another option is to compare your results with those from other simulations that do include self-gravity. This can help you understand the limitations of your current approach and potentially guide future improvements to your model.

Overall, I think it's important to continue questioning and refining your simulation approach as you gather more data and insights. Keep exploring and collaborating with your colleagues, and don't be afraid to try new approaches. Best of luck with your research!