| | 4 | = Parameter Space for Planet Sims = |
| | 5 | Successfully recreated Run 5 (Aniso) from Jonathan's simulations, after meeting and fixing some of the code. Most runs are taking 5-8 hours with 1 level AMR (did check, optimization flag is set to level 3 in makefile). Used momenta to compare relative strength of outflows, made density movies. |
| | 6 | |
| | 7 | [[Image(aniso.gif, width=300)]] |
| | 8 | |
| | 9 | [[Image(aniso_new.gif, width=300)]] |
| | 10 | |
| | 11 | In comparison to Aniso, changing lambda performs as expected - with lambda = 5, there is a marked increase in the strength of the wind, and with lambda = 15 there is very little to no wind (size of planet changes as well). |
| | 12 | |
| | 13 | [[Image(aniso_lambda=5.gif, width=300)]] |
| | 14 | |
| | 15 | [[Image(aniso_lambda=15.gif, width=300)]] |
| | 16 | |
| | 17 | Changing the mass of the planet wasn't quite as clear. Overall, it doesn't appear to have affected the wind very much. Again, the planet size is related to the mass (since density is also specified). It is hard to see a wind on the smallest (.25 M,,J,,) planet, but momentum plots appear to support its existence. |
| | 18 | |
| | 19 | [[Image(aniso_pmass=1.gif, width=300)]] |
| | 20 | |
| | 21 | [[Image(aniso_pmass=.5.gif, width=300)]] |
| | 22 | |
| | 23 | [[Image(aniso_pmass=.25.gif, width=300)]] |
| | 24 | |
| | 25 | Changing the temperature of the planet also affects the radius (through lambda). A 5x hotter planet appears to have a stronger outflow at the end, although it takes a significant amount of time to gain significant size (perhaps should run this simulation for longer). A planet with .5 T doesn't appear to be very different, qualitatively, from the original run. |
| | 26 | |
| | 27 | [[Image(aniso_ptemp=5e4.gif, width=300)]] |
| | 28 | |
| | 29 | [[Image(aniso_ptemp=5e3.gif, width=300)]] |
| | 30 | |
| | 31 | Finally (for the moment), changed ambient temperature to lower values. Would also like to explore higher values to see if they have much effect. The 50K, 25K, and 3K runs all have similar maximum momenta, approx. 2x the Aniso run, which seems to suggest a stronger outflow, but the density plots look nearly identical. |
| | 32 | |
| | 33 | [[Image(aniso_ambtemp=50.gif, width=300)]] |
| | 34 | |
| | 35 | [[Image(aniso_ambtemp=25.gif, width=300)]] |
| | 36 | |
| | 37 | [[Image(aniso_ambtemp=3.gif, width=300)]] |
| | 38 | |
| | 39 | What parameters are best to plot? |
| | 40 | |
| 4 | 41 | = Fluid Approximation of Charge Exchange = |
| 5 | 42 | In [http://iopscience.iop.org/article/10.3847/0004-637X/820/1/3/pdf Christie et al.], they calculate the mean free path (sound speed over rate of reaction) for charge exchange and note that it is less than the planetary radius (in regions dominated by the planetary wind) to justify using the fluid approximation, with mixing and exchange primarily at turbulent boundaries. In [http://iopscience.iop.org/article/10.1088/0004-637X/693/1/23/pdf Murray-Clay et al.], they justify the fluid approximation in general by comparing the scale height H to the mean free path of a particle, with the fluid approximation holding for H > lambda,,mfp,, at the sonic point (in other words, the exobase is above the sonic point). Thus, H > R,,p,, as well, and therefore greater than mfp of charge exchange near the planet. |
