Update 2/11: Wind Tunnel Runs 004AB, 005AB, and comparison to 003

Finished Runs

Just to summarize the four recent runs -

WT Run 004A

  • Sim parameters:

  1. Spacial resolution: base 643, finest 10243 (4 levels)
  2. Time Resolution: 0.005CU = 2.2e3s
  3. Sim time: 0.5 CU, 100 frames
  4. Accretion = none
  5. Poisson solver convergence tolerance: 1e-6
  6. Run time: less than a day.
  7. Softening Length: 8CU (16 cells)

WT Run 004B

  • Sim parameters:

  1. Spacial resolution: base 643, finest 10243 (4 levels)
  2. Time Resolution: 0.005CU = 2.2e3s
  3. Sim time: 0.5 CU, 100 frames
  4. Accretion = Krumholtz
  5. Poisson solver convergence tolerance: 1e-6
  6. Run time: less than a day.
  7. Softening Length: 8CU (16 cells)
  8. Accretion Radius (particle radius): 0.5CU (1 cell)

WT Run 005A

  • Sim parameters:

  1. Spacial resolution: base 643, finest 20483 (5 levels)
  2. Time Resolution: 0.005CU = 2.2e3s
  3. Sim time: 0.25 CU, 50 frames
  4. Accretion = none
  5. Poisson solver convergence tolerance: 1e-3
  6. Run time: paused after 1.5 days. Estimated next 0.25 CU takes 4.5 days.
  7. Softening Length: 4CU (16 cells)

WT Run 005B

  • Sim parameters:

  1. Spacial resolution: base 643, finest 10243 (5 levels)
  2. Time Resolution: 0.005CU = 2.2e3s
  3. Sim time: 0.5 CU, 100 frames
  4. Accretion = Krumholtz
  5. Poisson solver convergence tolerance: 1e-3
  6. Run time: less than a day.
  7. Softening Length: 4CU (8 cells)
  8. Accretion Radius (particle radius): 4CU (8 cell)

Run 005A log Rho movie

Run 005A vx movie

Run 005B log Rho movie

Run 005B vx movie

Different definitions of softening lengths

The softening function used by both Luke and me is spline interpolation. As noted by Ohlmann, the softened potential is steeper compared to Plummer's potential. By comparing the potential at r=0, Ohlmann argues for a factor of conversion 2.8. Then in Plummer's term my softening length is within 3 pixels. Yet Ohlmann claims that a 10 pixel resolution is necessary.

Drag force: a first comparison

First guesses:

  • Due to self-gravity, drag force does not asymtote to stable value?
  • Dynamical friction dominates over momentum accretion?

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