Changes between Version 19 and Version 20 of u/erica/RadHydro
- Timestamp:
- 03/30/16 11:38:08 (9 years ago)
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u/erica/RadHydro
v19 v20 90 90 [[Image(thydro.png, 35%)]] 91 91 92 This means, depending on the relative strengths of coupling and diffusion, there will be some regions of radiative heating and some of cooling. For this picture here (which is very rough -- a diffusion wave, and coupling 'wave' may have different concavity than shown here):92 This means, depending on the details of the rad-hydro, there will be some regions of radiative heating and some of cooling. For this picture here (which is very rough btw -- a diffusion wave, and coupling 'wave' may have different concavity than shown here), we have: 93 93 94 94 [[Image(heatingregions.png, 35%)]] 95 95 96 96 This process will continue until equilibrium has been reached -- that is, no more gradients in E (and thus no more diffusion), and the energy in the radiative field matches the energy being produced by the blackbody (i.e. E=B). 97 98 Over time the energy (which is continuously being injected into the center few zones), diffuses into the uniform medium:99 100 [[Image(DiffusionWave.png, 35%)]]101 102 103 104 How fast this diffusion takes place depends on [[latex($\kappa_R$)]]. Once E has diffused into the adjacent cells, [[latex($E>B$)]], and so, [[latex($\rho e$)]] will increase in those zones. This leads to an increase in T, and thus, an increase in B. How fast the energy is transferred from the radiation field to the gas depends on [[latex($\kappa_P$)]]. Adjusting the planck opacity can be thought of then as adjusting the specific heat capacity of the gas. A large [[latex($\kappa_P$)]] means the gas can absorb the radiation quickly (and thus the radiation and gas are strongly coupled), and vice versa.