Changes between Version 22 and Version 23 of u/erica/OutflowFeedback
- Timestamp:
- 10/31/17 12:32:32 (7 years ago)
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u/erica/OutflowFeedback
v22 v23 24 24 Note, this accreted angular momentum is the sink's ''spin'' angular momentum, rather than its orbital angular momentum. This is because in addition to enforcing mass, momentum, and energy conservation between the gas and the sink particle, we also conserve the COM of the system. 25 25 26 Question -- Why do we conserve the center of mass (COM) of the system -- is it the location of the sink particle (if so, doesn't that coincide with the gravitational potential minimum?).27 28 Question -- What is the spin angular momentum of the sink and how do we calculate it?29 26 30 27 So to recap, mass, energy, linear and angular momentum, and the COM is **conserved** between the gas and the sink particle in AstroBEAR's accretion module. … … 41 38 If this at first seems unphysical to you because the speed is potentially greater than the flow speed of accreted material (and should be in order to get outflow), remember this is a SGS model and we envision the gas as accelerating due to gravity as it approaches the surface of the star. 42 39 43 Question - how is the Bondi speed used in the accretion module? - If we can estimate the infall speed of the material around the sink as approaching the Bondi limit (is this simply pressureless collapse?), then when does $V_{out}$ > ~ $f_a V_{bondi}$, where $f_a$ is the fraction of accreted mass to be injected in outflow. Related question - are there any quantities that are stepped on each timestep in the kernel, or are quantities only summed/subtracted during injection/accretion steps...? Thinking how does the flow change over time such that the kernel switches from infall to outflow.44 45 40 == Angular momentum injection == 46 41 … … 53 48 == Questions / Tests == 54 49 55 === Is the amount of "push" in the outflow subject to resolution? === 50 === Are there any quantities that are stepped on each timestep in the kernel, or are quantities only summed/subtracted during injection/accretion steps? === 51 52 Thinking how does the flow change over time such that the kernel switches from infall to outflow. 53 54 === Is the amount of "push" in the outflow subject to resolution? === 55 56 === When we remove gas from cells, do we need to apply a pressure to those cells (if not, do we see any artificial waves generated due to the sudden pressure loss in those cells?) === 57 58 === How is the Bondi speed used in the accretion module? === 59 60 If we can estimate the infall speed of the material around the sink as approaching the Bondi limit (is this simply pressureless collapse?), then when does $V_{out}$ > ~ $f_a V_{bondi}$, where $f_a$ is the fraction of accreted mass to be injected in outflow. 61 62 === Why do we conserve the center of mass (COM) of the system -- is it the location of the sink particle (if so, doesn't that coincide with the gravitational potential minimum?) === 63 64 65 === What is the spin angular momentum of the sink and how do we calculate it? === 66 67 56 68 57 69 [[CollapsibleStart(Development Progress)]] … … 103 115 [[CollapsibleEnd]] 104 116 105
