Changes between Version 47 and Version 48 of FluxLimitedDiffusion

Timestamp:

03/21/13 13:16:08 (12 years ago)

Author:

Jonathan

Comment:

—

FluxLimitedDiffusion

@@ -252 +252 @@
 
 === Constant Slope Boundary ===
-Here we want the flux to be constant so energy does not pile up near the boundary
-[[latex(E^{n+1}_g=2 E^{n+1}_i - E^{n-1}_j \mbox{ and } E^n_g=2 E^n_i-E^n_j)]] where cell 'j' is interior of cell 'i'. Then we would set [[latex(\alpha_i = \alpha_i-\alpha_g)]] and set [[latex(\alpha_g = 0)]]
+Here we want the flux to be constant so energy does not pile up near the boundary.  So we want [[latex(\alpha_g = \alpha_i) \mbox { and } E_g=2*E_i-E_j)]]  This will effectively cancel all terms related to alpha.  However, we want to maintain this boundary during the implicit solve, so we also need to modify the matrix connections and subtract [[latex(\alpha_g \mbox{ from } \alpha_i)]] but this will effectively zero out the matrix connections to the interior as well.  This can also be done by setting [[latex(\alpha_g = \alpha_i = 0)]]
 
 === Reflecting Boundary ===
@@ -277 +276 @@
 ||  Open  ||   [[latex(c \frac{\Delta t}{\Delta x})]]   ||    ||  [[latex(0)]]     ||  ||
 ||  User-Defined opacity and Temperature   ||     ||       ||   [[latex( \frac{4 \pi}{c} B(T_g))]]   ||   ||
-||  Extrapolate radiation density   ||   ||   ||
-||  Extrapolate Flux  ||  [[latex(0)]]   ||  [[latex(0)]]  ||  ||  ||
-||  Reflecting   ||   [[latex(0)]]   ||  ||    ||  ||
-||  User-Defined Flux   ||   [[latex(0)]]   ||  ||  || [[latex(F_0 \frac{\Delta t}{\Delta x})]]   ||
+||  Extrapolate Flux  ||  [[latex(0)]]   ||  [[latex(0)]]  || X ||  ||
+||  Reflecting (Extrapolate E)   ||   [[latex(0)]]   ||  ||  X ||  ||
+||  User-Defined Flux   ||   [[latex(0)]]   ||  || X || [[latex(F_0 \frac{\Delta t}{\Delta x})]]   ||