GravoTurbulent Params

Just talked with Eric and we decided to try the following set of runs…

Constant params

  • rho=100 particles/cc
  • Mach = 5
  • cells per jeans length 25 (or higher if computationally feasible)

Variable params

Run alpha Gravity EOS
A 1 SG II
B .2 SG II
C 1 SG ISO
D 1 Static II
E .2 Static II

where

  • II is Inoue and Inutsuka
  • ISO is isothermal at 41 K
  • All runs will start with windowed velocity field of fully developed turbulence.

To achieve a virial parameter of .2, we need to make the density higher or make the box larger… Adjusting the box size is the easiest thing as it will keep the temperature and the velocities the same. Before we were using R = 50 pc and a Mach number of 8.5

We also discussed a steady state gravo-turbulence where mass is taken from small scale collapsed structures and put back in at the large scale with or without additional velocity forcing.

Fully Developed Turbulence

Run 1283 2563 5123 Xmu M_turb v_turb alpha alpha t_cross/v_turb t_cross Temp SoundSpeed n lBox
ISO 10 2 2 1.4 12.5 96.8272888743251 2.5 0.01333 0.516383352062004 20 4.472135955 100 50
IICool 10 2 2 1.27 12.5 66.4996345290655 1.1792 0.01333 0.751883831 16.9812533471972 5.31997076232524 100 50

Note for the isothermal run, only the mach number of the turbulence is important - everything else is scalable

For the IICool simulation the mach number, the mean density, and the box size all become important considerations…

So now we have turbulence initial conditions that we need to map onto a cloud

The Total Mass of the system in cu is 0.42836E+07 - and since the ambient has a volume of 1003-(4/3*pi*203) and density of 1, this gives a cloud mass of approximately 3.3e6 or a mean density of 51 though it should be closer to 100.. It is likely less because of the softening… If we consider the radius to only be 80% then the mean density would be 99 particles/cc. There is still a net velocity of order 9 cu and a velocity dispersion (mass weighted) of 33. Given that the sound speed is of order 4.5 this is a mach number of 8

For the isothermal run - the density can be arbitrarily scaled without effecting the dynamics… For the IICooling run - this is not the case. If should be possible to adjust the window to raise the min density…

Due to an accounting error… the mach number ended up not being the same for the two runs…

Run 1283 2563 5123 Xmu M_turb v_turb alpha alpha t_cross/v_turb t_cross Temp SoundSpeed n lBox
ISO 10 2 2 1.4 21.5 96.8272888743251 2.5 0.01333 0.516383352062004 20 7.746183109946008 100 50
IICool 10 2 2 1.27 12.5 66.4996345290655 1.1792 0.01333 0.751883831 16.9812533471972 5.31997076232524 100 50

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