[Archive] wake problem

SPIS
#1

Message by wang ji:
Windows XP SP2 (32bit), SPIS 3.6
Wake formation in LEO: No secondaries
LEO enviroment:
e- 0.1eV
p+ 0.05eV N: 1e12/m3
Vs/c=7700m/s

GMSH or Ultraedit

edit \wakesim\wake.geo Point (1) = { 4.000, 4.000, 6.000, 0.5} Point (2) = { 4.000, 4.000, -6.000, 0.5} Point (3) = {-4.000, 4.000, -6.000, 0.5} Point (4) = {-4.000, 4.000, 6.000, 0.5} Point (5) = { 4.000, -4.000, 6.000, 0.5} Point (6) = { 4.000, -4.000, -6.000, 0.5} Point (7) = {-4.000, -4.000, -6.000, 0.5} Point (8) = {-4.000, -4.000, 6.000, 0.5} Point (9) = {-1.040, 1.040, 2.600, 0.5} Point (10)= {-1.040, 1.040, -2.600, 0.5} Point (11)= {-1.560, 1.040, -2.600, 0.5} Point (12)= {-1.560, 1.040, 2.600, 0.5} Point (13)= {-1.040, -1.040, 2.600, 0.5} Point (14)= {-1.040, -1.040, -2.600, 0.5} Point (15)= {-1.560, -1.040, -2.600, 0.5} Point (16)= {-1.560, -1.040, 2.600, 0.5} Line (1) = {1, 2}

Line (2) = {2, 3}

Line (3) = {3, 4}

Line (4) = {4, 1}

Line (5) = {5, 6}

Line (6) = {6, 7}

Line (7) = {7, 8}

Line (8) = {8, 5}

Line (9) = {1, 5}

Line (10) = {2, 6}

Line (11) = {3, 7}

Line (12) = {4, 8}

Line (13) = {9, 10}

Line (14) = {10, 11}

Line (15) = {11, 12}

Line (16) = {12, 9}

Line (17) = {13, 14}

Line (18) = {14, 15}

Line (19) = {15, 16}

Line (20) = {16, 13}

Line (21) = {9, 13}

Line (22) = {10, 14}

Line (23) = {11, 15}

Line (24) = {12, 16}

Line Loop (38) = {1, 2, 3, 4}

Plane Surface (38) = {38}

Line Loop (40) = {5, 6, 7, 8}

Plane Surface (40) = {40}

Line Loop (42) = {1, 10, -5, -9}

Plane Surface (42) = {42}

Line Loop (44) = {3, 12, -7, -11}

Plane Surface (44) = {44}

Line Loop (46) = {4, 9, -8, -12}

Plane Surface (46) = {46}

Line Loop (48) = {2, 11, -6, -10}

Plane Surface (48) = {48}

Line Loop (50) = {13, 14, 15, 16}

Plane Surface (50) = {50}

Line Loop (52) = {17, 18, 19, 20}

Plane Surface (52) = {52}

Line Loop (54) = {13, 22, -17, -21}

Plane Surface (54) = {54}

Line Loop (56) = {15, 24, -19, -23}

Plane Surface (56) = {56}

Line Loop (58) = {16, 21, -20, -24}

Plane Surface (58) = {58}

Line Loop (60) = {14, 23, -18, -22}

Plane Surface (60) = {60}

Surface Loop (74) = {44, 38, 42, 48, 40, 46, 50, 54, 60, 56, 58, 52}

Volume (74) = {74}

Physical Surface (76) = {50, 52, 54, 56, 58, 60}

Physical Surface (78) = {38, 40, 42, 44, 46, 48}

Physical Volume (79) = {74}

2 SPIS-UI
(1) File->Save project
\wakesim
(2) GEOM->Geometry/CAD Manager

  1. Add file \wakesim\wake.geo
b. Choose wake.geo and Click "Set as main" c. Update project (3) LOAD GEOM (4) Properties->Load Default Properties Catalog (5) Properties->Editing Properties->Material Editor NONE ??? (6) Properties->Editing Properties->ElecNode Editor NONE ??? (7) Properties->Editing Properties->Plasma Editor NONE ??? (8) Groups->Edit Groups
  1. 76 SURFACE Material: Al oxyde ElecNode: Spacecraft ground (ElecNode-0) Plasma: Spacecraft, default.
b. 78 SURFACE Material: NONE ElecNode: NONE Plasma: Boundary, default. c. 79 VOLUME Material: NONE ElecNode: NONE Plasma: Plasma Model in Volume, default. default. d. OK (9) Call the mesher (10)Convert the GEOM (CAD) groups into mesh groups (11)Map the fields on the mesh according to groups (12)Call the global parameters editor
  1. Spacecraft
  1. CSat 1.0e-9 default
2. electricCircuitFilename clear all content of circuit.txt or leave this Blank 3. electricCircuitIntergrate 1 for floating potential 4. initPot 0.0 5. initPotFlag 1 default 6. sourceFlag1/2/3/4 0.0 default 7. Others default b. Surface Interactions
  1. electronSecondaryDensification 1.0 default
2. electronSecondaryEmission 0 3. erosion 0 default erosion\* default 4. inducedConductivity 0 default 5. photoEmission 0 default photoElectron\* default 6. protonSecondaryEmission 0 proton\* default 7. secondaryDt -1 default secondary\* default 8. sunX/Y: default sunZ: 0.0 9. surfaceConductivity/volumeConductivity: 0 default 10. Others default c. Poisson equation all default d. Outputs all default e. Plasma

electronDensity 1e12

2 electronTeperature 0.1 
   3 ionDensity  1e12

   4 ionTemperature 0.05

   5 ionVx 7700

   6 Other default
f. Simulation control
   duration 1.0e-4

all default

  1. B Field
all default
  1. Volume Interactions
volInteract 0.0 default all default
  1. Save and Quit
(13)Convert Data form UI to NUM data structure (14)launch SOLVER till time is up. (15)Fields->DataFields Manager Maybe It can be a tutorial, why does the simulation show particles number density is nearly zero?
#2

Message by Pablo Promenzio:
hi wang ji,
I try to simulate the wake that yo had posted but it didn´t work. I would appreciate if you could tell me if it worked to you, because i´m trying to simulate a leo environment and i do not know the parameters that i have to set up in the global parameters and also the criterion of the radio of the external boundary that i have to use in LEo. I knew that in GEO is 1/4 of the debye length distance, but in LEO I don´t know. If you have some ideas, please tell me…
Best Regards,
Pablo Promenzio.

#3