AUGUST 8, 2000
LAS VEGAS, NEVADA
TUESDAY, AUGUST 8
Sovinec, Gianakon, Hegna, Kruger, Tarditi, Jardin, Leboeuf, Chu, Liu,
Dagazian, Nebel, Schnack, Chance
8:30 - 10:30 AM CODE DEVELOPMENT
- Generalized elements (Carl)
Gen. elements are being applied to an "analytic" TOQ equilibrium,
packed around the q=3D2,3 surfaces. Linear results have been converged
to within 1%. Grid was 41
21, with quartic elements. (Mode with S =3D 10**6 has been seen with 30
10 grid.) Still need to use div_B diffusivity to help satisfy the
solenoidal containt. Results are much less sensitive to exact value of
div_B diffusivity. Rule of thumb: div_B_diff ~ L**2/dt. Carl is very
encouraged by these results. This is all for logical quadrilateral
elements. Triangular elements are a "mid-term"
(~ 6 months) goal.
Convergence properties (dt*dx error) "may" be eliminated by going to
- Vacuum and Pre-/post-processing issues
Vacuum representation is intimately tied to pre-processing.=20
Improvements have been made to fluxgrid to better represent vacuum.=20
The number of splines have been reduced from
3 to 1 to reduce errors.
Theta-packing has been added.
Working on linear toroidal benchmark and nonlinear calculation. For
nonlinar, need to add SI resitive solve.
- Resistive wall (Tom)
Tom reviewed his progress on resistive wall bc's. Slab and cylinder
are implemented. Torus is formulated. Tom is working on this with
- Neo-classical closures (Tom)
All initializations work with generalized
Previous pressure loss problems are now attributed to pollution of
parallel heat flux into perp. heat flux. Tests for this equilibrium
indicate that max. attainable anisotropt may be 10**6. This is too
small for NT threshhold for this case. Tom has identified a better NT
- Kinetic closures/particles (Charlson)
Carl reviewed status of this work as given to him by Scott P. and
Also reported visualization results with
10:30 AM - 12:30 PM APPLICATIONS
- High-S/D3D #86144.2250 (Dalton)
Blah, blah, blah....... Lot's of meaningless,
- High-beta disruption (Dalton, Alfonso)
Still numerically unstable. Should try again with generalized elements
and larger dib_b_d.
- SSPX (Alfonso)
Still problems with nonlinear case.
- ET (Alfonso)
Linear runs look OK. Nonlinear runs go unstable. Should check: 1)
time centering; 2) Cell Reynolds' number.
- Low R/a RFPs (Carl)
Has found PURE helical 1/3 state (pure 1/3 + harmonics) at R/a=3D1.1,
S=3D10**6, Pr=3D1. (Cylindrical state doesn't
show helicl state.)
12:30 PM - 2:00 PM LUNCH
2:00 PM - 4:00 PM NIMROD/M3D COMPARISON CASES
(Please be prepared to show what you'll discuss at the Macroscopic
Modeling meeting, to follow)
- Tearing modes (Carl, Tom, Scott)
We have preliminary linear results.
- Two-fluid (Rick)
Comparison with Linda Sugayama's case.
- Evaluation of collaboration (all)
- How can things be improved? (all)
4:00 PM - 5:30 PM PLANNING
- Develop goals and milestones for next 6
Mid-term. Reports Oct-Nov time-frame:
1. Generalized elements for triangles
2. Nonlinear vacuum region
3. Resistive wall in a torus
4. Nonsymmetric matrices
5. Revisit algorithm for flow.
6. Testing genralized elements (all)
7. Begin plasma thruster problem (Alfonso)
8. Formulate surface terms (like applied voltages) as surface
9. Comparison/benchmark problems.
5:30 PM - 6:00 PM OTHER ISSUES
- The view from Germantown (Rostom)
- Place and date for next team meeting
Proposition: Germantown the week before Thanksgiving
IT IS AGREED!!!!
6:00 PM ADJOURN