DRACO Research Update

1
DRACO Research Update

• A Presentation By
• Randy Spicer
• February 9, 2006

2
DRACO Research Update

• DRACO Can Now
• Determine what surface was hit
• Perform Surface Interaction
• Elastic Collisions
• Absorption
• DRACO Problems
• Code does not work 100 of the time
• Code does not compute partial time steps
• Interactions are only material based
• Surface ambiguity

3
The DRACO Code

• Complete Algorithm
• New Cell Location Added
• Location_Boundary
• Loops for Internal
• Loops to 1 dx
• In-Progress Algorithm
• Move particle to surface
• Perform partial time step
• Spectral collision

• If (cell_locationc.typeLOCATION_BOUNDARY)
• secell_locationc.surf_element
• else if (cell_locationc.typeLOCATION_INTERFACE
  )
• eDetermineParticleTet(mesh,part-gtx,c5)
• if (element_locatione.typeLOCATION_INTERFACE
• seelement_locatione.surf_element

4
JPC Paper Simulation

• Simulation
• Satellite at GEO
• Ion thrusters attached
• Satellite at LEO?
• Research
• Compare spacecraft charging
• Surface Effects

5
My Algorithm Works!

• It works!!... Most of the time.
• 94
• Remaining 6 is problem with Volcar
• More testing to come

• Output
• 15 Particle 7722 hit surface 566
• 17 Particle 2181 hit surface 566
• 21 Particle 3374 hit surface 446
• 21 Particle 6001 hit surface 566
• 22 Particle 5228 hit surface 432
• 23 Particle 7988 hit surface 432
• 23 Particle 2062 hit surface 446
• 24 Particle 4702 hit surface 446
• 24 Particle 451 hit surface 446
• 24 Particle 3526 hit surface 446
• 25 Particle 3332 hit surface 432
• 25 Particle 8238 hit surface 454
• 25 Particle 5703 hit surface 566
• 26 Particle 915 hit surface 432

6
Test Simulation

• Hollow cylinder
• Single particle inside
• Monitor
• Energy
• Momentum
• Velocity
• See how particle reflects off surfaces

7
Questions?