Merge pull request #218 from mabarnes/better-wall-bc-init

Add Maxwellian away from walls in initial condition for wall-bc sims
mabarnes · May 27, 2024 · 73f8bf5 · 73f8bf5
2 parents e2a6c33 + 9163c56
commit 73f8bf5
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Showing 5 changed files with 40 additions and 31 deletions.
diff --git a/moment_kinetics/src/initial_conditions.jl b/moment_kinetics/src/initial_conditions.jl
@@ -636,6 +636,15 @@ function init_ion_pdf_over_density!(pdf, spec, composition, vpa, vperp, z,
                                             right_weight*upper_z_pdf_buffer)
             end
 
+            # Add a non-flowing Maxwellian (that vanishes at the sheath entrance boundaries) to try to
+            # avoid the 'hole' in the distribution function that can drive instabilities.
+            @loop_z_vperp iz ivperp begin
+                @. pdf[:,ivperp,iz] += spec.z_IC.density_amplitude *
+                                      (1.0 - (2.0 * z.grid[iz] / z.L)^2) *
+                                      exp(-(vpa.grid^2 + vperp.grid[ivperp]^2)
+                                          / vth[iz]^2) / vth[iz]
+            end
+
             # Get the unnormalised pdf and the moments of the constructed full-f
             # distribution function (which will be modified from the input moments).
             convert_full_f_ion_to_normalised!(pdf, density, upar, ppar, vth, vperp,

diff --git a/moment_kinetics/test/fokker_planck_time_evolution_tests.jl b/moment_kinetics/test/fokker_planck_time_evolution_tests.jl
@@ -39,47 +39,47 @@ const expected =
    [-3.0, -2.5, -2.0, -1.5, -1.0, -0.5, 0.0, 0.5, 1.0, 1.5, 2.0, 2.5, 3.0],
    [0.155051025721682, 0.644948974278318, 1.000000000000000, 1.500000000000000, 2.000000000000000, 2.500000000000000, 3.000000000000000],
    # Expected phi:
-   [-1.267505494648937, -1.275683298550937],
+   [-1.268504994982021, -1.276675261324553],
    # Expected n_ion:
-   [0.2815330322340072, 0.2792400986636072],
+   [0.28125178045355353, 0.278963240220169],
    # Expected upar_ion:
    [0.0, 0.0],
    # Expected ppar_ion:
-   [0.17982280248048935, 0.14891126175332367],
+   [0.17964315932116812, 0.148762861611732],
    # Expected pperp_ion
-   [0.14340146667506784, 0.1581377822859991],
+   [0.14325820846660123, 0.15798027481288696],
    # Expected qpar_ion
    [0.0, 0.0],
    # Expected v_t_ion
-   [1.0511726083010418, 1.0538509291794658],
+   [1.0511726083010418, 1.0538484394097123],
    # Expected dSdt
-   [0.0, 1.1853081348031516e-5],
+   [0.0, 1.1831920390587679e-5],
    # Expected f_ion:
    [0.0 0.0 0.0 0.0 0.0 0.0 0.0;
-    0.0006199600161806666 0.00047805300997075977 0.0002665817112117718 7.637693901737056e-5 1.3272321881722645e-5 1.3988924344690309e-6 0.0;
-    0.005882016862626724 0.0045356406743786385 0.002529256854781707 0.0007246442213864763 0.00012592428394890537 1.3272321881722645e-5 0.0;
-    0.03384866997225574 0.026100809957763767 0.01455486826237011 0.004170039574837177 0.000724644221263874 7.637693900444835e-5 0.0;
-    0.11813810317200342 0.09109664226661075 0.05079917556123135 0.01455420747483572 0.0025291420266981487 0.0002665696084208068 0.0;
-    0.22957946520936198 0.17702940755267918 0.0987187642706944 0.0282833995036643 0.004914917865936108 0.0005180285318549189 0.0;
+    0.0006193406755051616 0.0004775754345362236 0.0002663153958159559 7.630063837899157e-5 1.3259062818903743e-5 1.3974949395295016e-6 0.0;
+    0.005876140721904817 0.0045311095648138235 0.00252673012465705 0.000723920301085391 0.00012579848546344195 1.3259062818903743e-5 0.0;
+    0.0338148551171386 0.026074735222541223 0.01454032793443568 0.004165873701136042 0.000723920300962911 7.630063836608227e-5 0.0;
+    0.11802008308891455 0.09100563662998079 0.05074842713409726 0.014539667807028695 0.0025266154112868616 0.0002663033051156912 0.0;
+    0.22935011509426767 0.1768525549976815 0.09862014412656786 0.028255144359305 0.00491000785807803 0.0005175110208340848 0.0;
     0.0 0.0 0.0 0.0 0.0 0.0 0.0;
-    0.22957946520936204 0.1770294075526792 0.0987187642706944 0.0282833995036643 0.004914917865936108 0.0005180285318549189 0.0;
-    0.11813810317200349 0.0910966422666108 0.050799175561231376 0.01455420747483573 0.0025291420266981487 0.0002665696084208068 0.0;
-    0.03384866997225574 0.026100809957763767 0.01455486826237011 0.004170039574837177 0.000724644221263874 7.637693900444835e-5 0.0;
-    0.005882016862626724 0.0045356406743786385 0.002529256854781707 0.0007246442213864763 0.00012592428394890537 1.3272321881722645e-5 0.0;
-    0.0006199600161806666 0.00047805300997075977 0.0002665817112117718 7.637693901737056e-5 1.3272321881722645e-5 1.3988924344690309e-6 0.0;
+    0.22935011509426778 0.17685255499768154 0.09862014412656786 0.028255144359305 0.00491000785807803 0.0005175110208340848 0.0;
+    0.1180200830889146 0.09100563662998083 0.05074842713409728 0.014539667807028703 0.0025266154112868616 0.0002663033051156912 0.0;
+    0.0338148551171386 0.026074735222541223 0.01454032793443568 0.004165873701136042 0.000723920300962911 7.630063836608227e-5 0.0;
+    0.005876140721904817 0.0045311095648138235 0.00252673012465705 0.000723920301085391 0.00012579848546344195 1.3259062818903743e-5 0.0;
+    0.0006193406755051616 0.0004775754345362236 0.0002663153958159559 7.630063837899157e-5 1.3259062818903743e-5 1.3974949395295016e-6 0.0;
     0.0 0.0 0.0 0.0 0.0 0.0 0.0;;;
     0.0 0.0 0.0 0.0 0.0 0.0 0.0;
-    0.0001712743622973216 7.105465094508053e-5 -7.829380680167827e-5 -0.00015364081956318698 -9.097098213067502e-5 -3.311284120491419e-5 0.0;
-    0.005883280697248667 0.004667594200766182 0.002855965521103658 0.0008138347136178689 2.44260649525292e-5 -9.753249634264602e-5 0.0;
-    0.02792209301450194 0.022385716644538384 0.01413535091105969 0.004677801530322722 0.0007105315221401102 -0.00022400635166536323 0.0;
-    0.08117458037332098 0.06563459159004267 0.04247673844050208 0.015087784332275832 0.0029056314178876035 -0.00023019804543218203 0.0;
-    0.15133793170654106 0.12313903060106579 0.08111673445361306 0.029975277983613262 0.00626735398468981 7.553501812465833e-6 0.0;
-    0.18493902160817713 0.15073513412904313 0.09976414473955808 0.037251581926306565 0.007941836186495122 0.00016196175024033304 0.0;
-    0.15133793170654092 0.12313903060106571 0.08111673445361306 0.02997527798361324 0.006267353984689816 7.553501812469816e-6 0.0;
-    0.081174580373321 0.06563459159004267 0.042476738440502065 0.015087784332275821 0.002905631417887614 -0.0002301980454321778 0.0;
-    0.027922093014501933 0.022385716644538384 0.014135350911059698 0.004677801530322729 0.0007105315221401184 -0.00022400635166536134 0.0;
-    0.005883280697248667 0.004667594200766184 0.002855965521103663 0.0008138347136178759 2.4426064952530956e-5 -9.753249634264635e-5 0.0;
-    0.0001712743622973275 7.105465094508572e-5 -7.829380680167411e-5 -0.00015364081956318568 -9.097098213067551e-5 -3.311284120491447e-5 0.0;
+    0.00017108987342944037 7.097261590252227e-5 -7.822316408658004e-5 -0.000153489754637506 -9.087984332447761e-5 -3.307937957312587e-5 0.0;
+    0.005877384425022921 0.004662912823128315 0.002853094592035005 0.0008130106752860298 2.4399432485772724e-5 -9.74348090421241e-5 0.0;
+    0.02789429969714529 0.022363413859309983 0.014121230173998248 0.004673094872084004 0.0007098078939540657 -0.0002237857510708618 0.0;
+    0.08109427896718696 0.06556961121847364 0.04243458963422585 0.01507272286376149 0.0029027058292680945 -0.0002299783231637593 0.0;
+    0.1511887162169901 0.12301753182687214 0.08103653941734254 0.029945484317773212 0.0062610744742386155 7.528837370841561e-6 0.0;
+    0.184756848099325 0.1505865499710698 0.09966561578213134 0.037214599991686845 0.007933889035324836 0.00016178010211991204 0.0;
+    0.1511887162169905 0.12301753182687247 0.08103653941734275 0.029945484317773295 0.006261074474238628 7.528837370846196e-6 0.0;
+    0.08109427896718732 0.06556961121847393 0.042434589634226055 0.015072722863761552 0.0029027058292681127 -0.0002299783231637549 0.0;
+    0.027894299697145436 0.022363413859310108 0.014121230173998337 0.00467309487208404 0.0007098078939540783 -0.00022378575107086105 0.0;
+    0.005877384425022965 0.00466291282312835 0.0028530945920350282 0.0008130106752860425 2.4399432485774198e-5 -9.743480904212476e-5 0.0;
+    0.00017108987342944414 7.097261590252536e-5 -7.822316408657793e-5 -0.0001534897546375058 -9.087984332447822e-5 -3.3079379573126077e-5 0.0;
     0.0 0.0 0.0 0.0 0.0 0.0 0.0])
 ###########################################################################################
 # to modify the test, with a new expected f, print the new f using the following commands
@@ -135,7 +135,7 @@ test_input_gauss_legendre = Dict("run_name" => "gausslegendre_pseudospectral",
                               "electron_physics" => "boltzmann_electron_response",
                               "fokker_planck_collisions" => Dict{String,Any}("use_fokker_planck" => true, "nuii" => 1.0, "frequency_option" => "manual"),
                               "z_IC_upar_amplitude1" => 0.0,
-                              "z_IC_density_amplitude1" => 0.001,
+                              "z_IC_density_amplitude1" => 0.0,
                               "z_IC_upar_amplitude2" => 0.0,
                               "z_IC_temperature_phase1" => 0.0,
                               "z_IC_temperature_amplitude1" => 0.0,

diff --git a/moment_kinetics/test/harrisonthompson.jl b/moment_kinetics/test/harrisonthompson.jl
@@ -74,7 +74,7 @@ test_input_finite_difference = Dict("n_ion_species" => 1,
                                     "initial_density1" => 1.0,
                                     "initial_temperature1" => 1.0,
                                     "z_IC_option1" => "gaussian",
-                                    "z_IC_density_amplitude1" => 0.001,
+                                    "z_IC_density_amplitude1" => 0.0,
                                     "z_IC_density_phase1" => 0.0,
                                     "z_IC_upar_amplitude1" => 0.0,
                                     "z_IC_upar_phase1" => 0.0,

diff --git a/moment_kinetics/test/recycling_fraction_tests.jl b/moment_kinetics/test/recycling_fraction_tests.jl
@@ -32,7 +32,7 @@ test_input = Dict("n_ion_species" => 1,
                   "initial_density1" => 1.0,
                   "initial_temperature1" => 1.0,
                   "z_IC_option1" => "gaussian",
-                  "z_IC_density_amplitude1" => 0.001,
+                  "z_IC_density_amplitude1" => 0.0,
                   "z_IC_density_phase1" => 0.0,
                   "z_IC_upar_amplitude1" => 1.0,
                   "z_IC_upar_phase1" => 0.0,

diff --git a/moment_kinetics/test/wall_bc_tests.jl b/moment_kinetics/test/wall_bc_tests.jl
@@ -30,7 +30,7 @@ test_input_finite_difference = Dict("n_ion_species" => 1,
                                     "initial_density1" => 1.0,
                                     "initial_temperature1" => 1.0,
                                     "z_IC_option1" => "gaussian",
-                                    "z_IC_density_amplitude1" => 0.001,
+                                    "z_IC_density_amplitude1" => 0.0,
                                     "z_IC_density_phase1" => 0.0,
                                     "z_IC_upar_amplitude1" => 0.0,
                                     "z_IC_upar_phase1" => 0.0,