Updates on rad feedback

Run 1.

2D, periodic boundary conditions, 1282 resolution. There is a sink particle in the middle of the box that is injecting a constant 'accretion energy' into the center zones of the grid.

Plot is of Etherm (left) and Erad (right) over time,

movie​

Thermal energy is derived from subtracting the specific kinetic energy from the total energy (as there are no magnetic fields or gravity in this simulation). The total radiative energy in the box at the start of the sim is, Erad=90. By the end, Erad=10,038.

Both the planck opacity and the roseland are set to =1d-6. The right plot shows that the radiative energy diffuses through the grid much faster than it is exchanging energy with the gas (i.e. changes in thermal energy happen slower). Hardly any change in thermal energy is happening at all, in fact. Unless I made an error with my expression, not sure how the radiative energy can be increasing, yet the thermal and total energy are equal..

There is a slight 'blip​' noticeable between the 1st and 3rd frame. Not immediately sure what this is being caused by either..

I would like to check that the total energy is being conserved. To do this, should I make an expression that sums E and Erad and check that it is constant over the course of the sim?

Overall though, the run seems to proceed nicely for these parameters (need to check my thermal energy expression still). I am trying to set up a simulation where I control the rate of energy injection, such that the total Erad doubles over the course of the simulation. In the meantime, experimented with differing opacities, as will show next.

Run 2.

High roseland opacity (radiation trapped, k=.001), low planck opacity (no coupling of radiation and gas, k=.1d-6).

movie​

Note, no blip in this run. I see that the thermal energy is not changing much here either. The max Erad is much greater than compared to above. The radiation being confined to a smaller space explains this.

Run 3.

High roseland opacity (radiation trapped, k=.001), High planck opacity (coupling of radiation and gas, k=10).

movie​

Now am starting to see an increase in thermal energy. Need to look at the equations and see how the opacities are coming in and how they are related to each other.

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