Natural Convection

7. Natural Convection#

Coupling of Navier-Stokes and heat transport

  • Change in temperature leads to gravity forces

  • Temperature is convected by fluid velocity

Rayleigh-Benard benchmark example

from ngsolve import *
import netgen.geom2d
import netgen.meshing
from ngsolve.webgui import Draw
import math

from ngs_templates.NavierStokes import *
from ngs_templates.ConvectionDiffusion import * 

ngsglobals.msg_level = 0
geo = netgen.geom2d.SplineGeometry()
geo.AddRectangle( (0,0), (0.06, 0.01), bcs=['b','r','t','l'])
mesh = Mesh(geo.GenerateMesh(maxh=0.002))
timestep = 0.1
navstokes = NavierStokes (mesh, nu=1.04177e-6, order=3, timestep = timestep,
                              inflow="", outflow="", wall="l|r|b|t", uin=(0,0) )

Tinitial = 293.5-50*y+y*(0.01-y)*1e3*sin(20/0.06*x*math.pi)

convdiff = ConvectionDiffusionEquation (mesh, order=3, lam=1.38e-7, \
                wind = navstokes.velocity, dirichlet="b|t", udir=Tinitial, timestep=timestep)
convdiff.SetInitial(Tinitial)

T0 = 293
beta = 2.07e-4
navstokes.AddForce ( (1-beta*(convdiff.concentration-T0))*(0, -9.81))

navstokes.SolveInitial()
scenev = Draw (navstokes.velocity, mesh, "velocity", vectors = { "grid_size" : 40 })
scenet = Draw (convdiff.concentration, mesh, "temp")

t, tend = 0, 1000
cnt = 0
with TaskManager():
    while t < tend:
        navstokes.DoTimeStep()
        convdiff.DoTimeStep()
        t = t+timestep
        cnt = cnt+1
        if cnt % 10 == 0:           
            print ('t = ', t, end='\r')
            scenev.Redraw()
            scenet.Redraw()
t =  0.9999999999999999
t =  2.0000000000000004
t =  3.0000000000000013
t =  4.000000000000002
t =  4.999999999999998
t =  5.999999999999995
t =  6.999999999999991
t =  7.999999999999988
t =  8.999999999999984
t =  9.99999999999998
t =  10.999999999999977
t =  11.999999999999973
t =  12.99999999999997
t =  13.999999999999966
t =  14.999999999999963
t =  15.99999999999996
t =  16.99999999999997
t =  17.999999999999986
t =  19.0
t =  20.000000000000014
t =  21.00000000000003
t =  22.000000000000043
t =  23.000000000000057
t =  24.00000000000007
t =  25.000000000000085
t =  26.0000000000001
t =  27.000000000000114
t =  28.000000000000128
t =  29.000000000000142
t =  30.000000000000156
t =  31.00000000000017
t =  32.000000000000185
t =  33.0000000000002
t =  34.00000000000021
t =  35.00000000000023
t =  36.00000000000024
t =  37.000000000000256
t =  38.00000000000027
t =  39.000000000000284
t =  40.0000000000003
t =  41.00000000000031
t =  42.00000000000033
t =  43.00000000000034
t =  44.000000000000355
t =  45.00000000000037
t =  46.000000000000384
t =  47.0000000000004
t =  48.00000000000041
t =  49.000000000000426
t =  50.00000000000044
t =  51.000000000000455
t =  52.00000000000047
t =  53.00000000000048
t =  54.0000000000005
t =  55.00000000000051
t =  56.000000000000526
t =  57.00000000000054
t =  58.000000000000554
t =  59.00000000000057
t =  60.00000000000058
t =  61.0000000000006
t =  62.00000000000061
t =  63.000000000000625
t =  64.00000000000064
t =  65.00000000000058
t =  66.00000000000053
t =  67.00000000000047
t =  68.00000000000041
t =  69.00000000000036
t =  70.0000000000003
t =  71.00000000000024
t =  72.00000000000018
t =  73.00000000000013
t =  74.00000000000007
t =  75.00000000000001
t =  75.99999999999996
t =  76.9999999999999
t =  77.99999999999984
t =  78.99999999999979
t =  79.99999999999973
t =  80.99999999999967
t =  81.99999999999962
t =  82.99999999999956
t =  83.9999999999995
t =  84.99999999999945
t =  85.99999999999939
t =  86.99999999999933
t =  87.99999999999928
t =  88.99999999999922
t =  89.99999999999916
t =  90.9999999999991
t =  91.99999999999905
t =  92.99999999999899
t =  93.99999999999893
t =  94.99999999999888
t =  95.99999999999882
t =  96.99999999999876
t =  97.9999999999987
t =  98.99999999999865
t =  99.9999999999986
t =  100.99999999999854
t =  101.99999999999848
t =  102.99999999999842
t =  103.99999999999837
t =  104.99999999999831
t =  105.99999999999825
t =  106.9999999999982
t =  107.99999999999814
t =  108.99999999999808
t =  109.99999999999802
t =  110.99999999999797
t =  111.99999999999791
t =  112.99999999999785
t =  113.9999999999978
t =  114.99999999999774
t =  115.99999999999768
t =  116.99999999999763
t =  117.99999999999757
t =  118.99999999999751
t =  119.99999999999746
t =  120.9999999999974
t =  121.99999999999734
t =  122.99999999999729
t =  123.99999999999723
t =  124.99999999999717
t =  125.99999999999712
t =  126.99999999999706
t =  127.999999999997
t =  128.99999999999696
t =  129.9999999999969
t =  130.99999999999685
t =  131.9999999999968
t =  132.99999999999673
t =  133.99999999999667
t =  134.99999999999662
t =  135.99999999999656
t =  136.9999999999965
t =  137.99999999999645
t =  138.9999999999964
t =  139.99999999999633
t =  140.99999999999628
t =  141.99999999999622
t =  142.99999999999616
t =  143.9999999999961
t =  144.99999999999605
t =  145.999999999996
t =  146.99999999999594
t =  147.99999999999588
t =  148.99999999999582
t =  149.99999999999577
t =  150.9999999999957
t =  151.99999999999565
t =  152.9999999999956
t =  153.99999999999554
t =  154.99999999999548
t =  155.99999999999542
t =  156.99999999999537
t =  157.9999999999953
t =  158.99999999999525
t =  159.9999999999952
t =  160.99999999999514
t =  161.99999999999508
t =  162.99999999999503
t =  163.99999999999497
t =  164.9999999999949
t =  165.99999999999486
t =  166.9999999999948
t =  167.99999999999474
t =  168.99999999999469
t =  169.99999999999463
t =  170.99999999999457
t =  171.99999999999451
t =  172.99999999999446
t =  173.9999999999944
t =  174.99999999999434
t =  175.9999999999943
t =  176.99999999999423
t =  177.99999999999417
t =  178.99999999999412
t =  179.99999999999406
t =  180.999999999994
t =  181.99999999999395
t =  182.9999999999939
t =  183.99999999999383
t =  184.99999999999378
t =  185.99999999999372
t =  186.99999999999366
t =  187.9999999999936
t =  188.99999999999355
t =  189.9999999999935
t =  190.99999999999343
t =  191.99999999999338
t =  192.99999999999332
t =  193.99999999999326
t =  194.9999999999932
t =  195.99999999999315
t =  196.9999999999931
t =  197.99999999999304
t =  198.99999999999298
t =  199.99999999999292
t =  200.99999999999287
t =  201.9999999999928
t =  202.99999999999275
t =  203.9999999999927
t =  204.99999999999264
t =  205.99999999999258
t =  206.99999999999253
t =  207.99999999999247
t =  208.9999999999924
t =  209.99999999999235
t =  210.9999999999923
t =  211.99999999999224
t =  212.99999999999218
t =  213.99999999999213
t =  214.99999999999207
t =  215.999999999992
t =  216.99999999999196
t =  217.9999999999919
t =  218.99999999999184
t =  219.9999999999918
t =  220.99999999999173
t =  221.99999999999167
t =  222.99999999999162
t =  223.99999999999156
t =  224.9999999999915
t =  225.99999999999145
t =  226.9999999999914
t =  227.99999999999133
t =  228.99999999999127
t =  229.99999999999122
t =  230.99999999999116
t =  231.9999999999911
t =  232.99999999999105
t =  233.999999999991
t =  234.99999999999093
t =  235.99999999999088
t =  236.99999999999082
t =  237.99999999999076
t =  238.9999999999907
t =  239.99999999999065
t =  240.9999999999906
t =  241.99999999999054
t =  242.99999999999048
t =  243.99999999999042
t =  244.99999999999037
t =  245.9999999999903
t =  246.99999999999025
t =  247.9999999999902
t =  248.99999999999014
t =  249.99999999999008
t =  250.99999999999002
t =  251.99999999998997
t =  252.9999999999899
t =  253.99999999998985
t =  254.9999999999898
t =  255.99999999998974
t =  256.99999999998994
t =  257.99999999999017
t =  258.9999999999904
t =  259.9999999999906
t =  260.99999999999085
t =  261.9999999999911
t =  262.9999999999913
t =  263.99999999999153
t =  264.99999999999176
t =  265.999999999992
t =  266.9999999999922
t =  267.99999999999244
t =  268.99999999999267
t =  269.9999999999929
t =  270.9999999999931
t =  271.99999999999335
t =  272.9999999999936
t =  273.9999999999938
t =  274.99999999999403
t =  275.99999999999426
t =  276.9999999999945
t =  277.9999999999947
t =  278.99999999999494
t =  279.99999999999517
t =  280.9999999999954
t =  281.9999999999956
t =  282.99999999999585
t =  283.9999999999961
t =  284.9999999999963
t =  285.99999999999653
t =  286.99999999999676
t =  287.999999999997
t =  288.9999999999972
t =  289.99999999999744
t =  290.99999999999767
t =  291.9999999999979
t =  292.9999999999981
t =  293.99999999999835
t =  294.9999999999986
t =  295.9999999999988
t =  296.99999999999903
t =  297.99999999999926
t =  298.9999999999995
t =  299.9999999999997
t =  300.99999999999994
t =  302.00000000000017
t =  303.0000000000004
t =  304.0000000000006
t =  305.00000000000085
t =  306.0000000000011
t =  307.0000000000013
t =  308.00000000000153
t =  309.00000000000176
t =  310.000000000002
t =  311.0000000000022
t =  312.00000000000244
t =  313.0000000000027
t =  314.0000000000029
t =  315.0000000000031
t =  316.00000000000335
t =  317.0000000000036
t =  318.0000000000038
t =  319.00000000000404
t =  320.00000000000426
t =  321.0000000000045
t =  322.0000000000047
t =  323.00000000000495
t =  324.0000000000052
t =  325.0000000000054
t =  326.0000000000056
t =  327.00000000000585
t =  328.0000000000061
t =  329.0000000000063
t =  330.00000000000654
t =  331.00000000000676
t =  332.000000000007
t =  333.0000000000072
t =  334.00000000000745
t =  335.0000000000077
t =  336.0000000000079
t =  337.00000000000813
t =  338.00000000000836
t =  339.0000000000086
t =  340.0000000000088
t =  341.00000000000904
t =  342.00000000000927
t =  343.0000000000095
t =  344.0000000000097
t =  345.00000000000995
t =  346.0000000000102
t =  347.0000000000104
t =  348.00000000001063
t =  349.00000000001086
t =  350.0000000000111
t =  351.0000000000113
t =  352.00000000001154
t =  353.00000000001177
t =  354.000000000012
t =  355.0000000000122
t =  356.00000000001245
t =  357.0000000000127
t =  358.0000000000129
t =  359.00000000001313
t =  360.00000000001336
t =  361.0000000000136
t =  362.0000000000138
t =  363.00000000001404
t =  364.00000000001427
t =  365.0000000000145
t =  366.0000000000147
t =  367.00000000001495
t =  368.0000000000152
t =  369.0000000000154
t =  370.00000000001563
t =  371.00000000001586
t =  372.0000000000161
t =  373.0000000000163
t =  374.00000000001654
t =  375.00000000001677
t =  376.000000000017
t =  377.0000000000172
t =  378.00000000001745
t =  379.0000000000177
t =  380.0000000000179
t =  381.00000000001813
t =  382.00000000001836
t =  383.0000000000186
t =  384.0000000000188
t =  385.00000000001904
t =  386.00000000001927
t =  387.0000000000195
t =  388.0000000000197
t =  389.00000000001995
t =  390.0000000000202
t =  391.0000000000204
t =  392.00000000002063
t =  393.00000000002086
t =  394.0000000000211
t =  395.0000000000213
t =  396.00000000002154
t =  397.00000000002177
t =  398.000000000022
t =  399.0000000000222
t =  400.00000000002245
t =  401.0000000000227
t =  402.0000000000229
t =  403.00000000002314
t =  404.00000000002336
t =  405.0000000000236
t =  406.0000000000238
t =  407.00000000002404
t =  408.0000000000243
t =  409.0000000000245
t =  410.0000000000247
t =  411.00000000002495
t =  412.0000000000252
t =  413.0000000000254
t =  414.00000000002564
t =  415.00000000002586
t =  416.0000000000261
t =  417.0000000000263
t =  418.00000000002655
t =  419.0000000000268
t =  420.000000000027
t =  421.0000000000272
t =  422.00000000002746
t =  423.0000000000277
t =  424.0000000000279
t =  425.00000000002814
t =  426.00000000002836
t =  427.0000000000286
t =  428.0000000000288
t =  429.00000000002905
t =  430.0000000000293
t =  431.0000000000295
t =  432.00000000002973
t =  433.00000000002996
t =  434.0000000000302
t =  435.0000000000304
t =  436.00000000003064
t =  437.00000000003087
t =  438.0000000000311
t =  439.0000000000313
t =  440.00000000003155
t =  441.0000000000318
t =  442.000000000032
t =  443.00000000003223
t =  444.00000000003246
t =  445.0000000000327
t =  446.0000000000329
t =  447.00000000003314
t =  448.00000000003337
t =  449.0000000000336
t =  450.0000000000338
t =  451.00000000003405
t =  452.0000000000343
t =  453.0000000000345
t =  454.00000000003473
t =  455.00000000003496
t =  456.0000000000352
t =  457.0000000000354
t =  458.00000000003564
t =  459.00000000003587
t =  460.0000000000361
t =  461.0000000000363
t =  462.00000000003655
t =  463.0000000000368
t =  464.000000000037
t =  465.00000000003723
t =  466.00000000003746
t =  467.0000000000377
t =  468.0000000000379
t =  469.00000000003814
t =  470.00000000003837
t =  471.0000000000386
t =  472.0000000000388
t =  473.00000000003905
t =  474.0000000000393
t =  475.0000000000395
t =  476.00000000003973
t =  477.00000000003996
t =  478.0000000000402
t =  479.0000000000404
t =  480.00000000004064
t =  481.00000000004087
t =  482.0000000000411
t =  483.0000000000413
t =  484.00000000004155
t =  485.0000000000418
t =  486.000000000042
t =  487.00000000004223
t =  488.00000000004246
t =  489.0000000000427
t =  490.0000000000429
t =  491.00000000004314
t =  492.00000000004337
t =  493.0000000000436
t =  494.0000000000438
t =  495.00000000004405
t =  496.0000000000443
t =  497.0000000000445
t =  498.00000000004474
t =  499.00000000004496
t =  500.0000000000452
t =  501.0000000000454
t =  502.00000000004565
t =  503.0000000000459
t =  504.0000000000461
t =  505.0000000000463
t =  506.00000000004655
t =  507.0000000000468
t =  508.000000000047
t =  509.00000000004724
t =  510.00000000004746
t =  511.0000000000477
t =  512.0000000000479
t =  513.0000000000481
t =  514.0000000000483
t =  515.0000000000485
t =  516.0000000000488
t =  517.000000000049
t =  518.0000000000492
t =  519.0000000000495
t =  520.0000000000497
t =  521.0000000000499
t =  522.0000000000501
t =  523.0000000000504
t =  524.0000000000506
t =  525.0000000000508
t =  526.000000000051
t =  527.0000000000513
t =  528.0000000000515
t =  529.0000000000517
t =  530.000000000052
t =  531.0000000000522
t =  532.0000000000524
t =  533.0000000000526
t =  534.0000000000529
t =  535.0000000000531
t =  536.0000000000533
t =  537.0000000000535
t =  538.0000000000538
t =  539.000000000054
t =  540.0000000000542
t =  541.0000000000545
t =  542.0000000000547
t =  543.0000000000549
t =  544.0000000000551
t =  545.0000000000554
t =  546.0000000000556
t =  547.0000000000558
t =  548.000000000056
t =  549.0000000000563
t =  550.0000000000565
t =  551.0000000000567
t =  552.000000000057
t =  553.0000000000572
t =  554.0000000000574
t =  555.0000000000576
t =  556.0000000000579
t =  557.0000000000581
t =  558.0000000000583
t =  559.0000000000585
t =  560.0000000000588
t =  561.000000000059
t =  562.0000000000592
t =  563.0000000000595
t =  564.0000000000597
t =  565.0000000000599
t =  566.0000000000601
t =  567.0000000000604
t =  568.0000000000606
t =  569.0000000000608
t =  570.000000000061
t =  571.0000000000613
t =  572.0000000000615
t =  573.0000000000617
t =  574.000000000062
t =  575.0000000000622
t =  576.0000000000624
t =  577.0000000000626
t =  578.0000000000629
t =  579.0000000000631
t =  580.0000000000633
t =  581.0000000000636
t =  582.0000000000638
t =  583.000000000064
t =  584.0000000000642
t =  585.0000000000645
t =  586.0000000000647
t =  587.0000000000649
t =  588.0000000000651
t =  589.0000000000654
t =  590.0000000000656
t =  591.0000000000658
t =  592.000000000066
t =  593.0000000000663
t =  594.0000000000665
t =  595.0000000000667
t =  596.000000000067
t =  597.0000000000672
t =  598.0000000000674
t =  599.0000000000676
t =  600.0000000000679
t =  601.0000000000681
t =  602.0000000000683
t =  603.0000000000686
t =  604.0000000000688
t =  605.000000000069
t =  606.0000000000692
t =  607.0000000000695
t =  608.0000000000697
t =  609.0000000000699
t =  610.0000000000701
t =  611.0000000000704
t =  612.0000000000706
t =  613.0000000000708
t =  614.000000000071
t =  615.0000000000713
t =  616.0000000000715
t =  617.0000000000717
t =  618.000000000072
t =  619.0000000000722
t =  620.0000000000724
t =  621.0000000000726
t =  622.0000000000729
t =  623.0000000000731
t =  624.0000000000733
t =  625.0000000000736
t =  626.0000000000738
t =  627.000000000074
t =  628.0000000000742
t =  629.0000000000745
t =  630.0000000000747
t =  631.0000000000749
t =  632.0000000000751
t =  633.0000000000754
t =  634.0000000000756
t =  635.0000000000758
t =  636.000000000076
t =  637.0000000000763
t =  638.0000000000765
t =  639.0000000000767
t =  640.000000000077
t =  641.0000000000772
t =  642.0000000000774
t =  643.0000000000776
t =  644.0000000000779
t =  645.0000000000781
t =  646.0000000000783
t =  647.0000000000786
t =  648.0000000000788
t =  649.000000000079
t =  650.0000000000792
t =  651.0000000000795
t =  652.0000000000797
t =  653.0000000000799
t =  654.0000000000801
t =  655.0000000000804
t =  656.0000000000806
t =  657.0000000000808
t =  658.0000000000811
t =  659.0000000000813
t =  660.0000000000815
t =  661.0000000000817
t =  662.000000000082
t =  663.0000000000822
t =  664.0000000000824
t =  665.0000000000827
t =  666.0000000000829
t =  667.0000000000831
t =  668.0000000000833
t =  669.0000000000836
t =  670.0000000000838
t =  671.000000000084
t =  672.0000000000842
t =  673.0000000000845
t =  674.0000000000847
t =  675.0000000000849
t =  676.0000000000852
t =  677.0000000000854
t =  678.0000000000856
t =  679.0000000000858
t =  680.0000000000861
t =  681.0000000000863
t =  682.0000000000865
t =  683.0000000000867
t =  684.000000000087
t =  685.0000000000872
t =  686.0000000000874
t =  687.0000000000877
t =  688.0000000000879
t =  689.0000000000881
t =  690.0000000000883
t =  691.0000000000886
t =  692.0000000000888
t =  693.000000000089
t =  694.0000000000892
t =  695.0000000000895
t =  696.0000000000897
t =  697.0000000000899
t =  698.0000000000902
t =  699.0000000000904
t =  700.0000000000906
t =  701.0000000000908
t =  702.0000000000911
t =  703.0000000000913
t =  704.0000000000915
t =  705.0000000000917
t =  706.000000000092
t =  707.0000000000922
t =  708.0000000000924
t =  709.0000000000927
t =  710.0000000000929
t =  711.0000000000931
t =  712.0000000000933
t =  713.0000000000936
t =  714.0000000000938
t =  715.000000000094
t =  716.0000000000942
t =  717.0000000000945
t =  718.0000000000947
t =  719.0000000000949
t =  720.0000000000952
t =  721.0000000000954
t =  722.0000000000956
t =  723.0000000000958
t =  724.0000000000961
t =  725.0000000000963
t =  726.0000000000965
t =  727.0000000000967
t =  728.000000000097
t =  729.0000000000972
t =  730.0000000000974
t =  731.0000000000977
t =  732.0000000000979
t =  733.0000000000981
t =  734.0000000000983
t =  735.0000000000986
t =  736.0000000000988
t =  737.000000000099
t =  738.0000000000992
t =  739.0000000000995
t =  740.0000000000997
t =  741.0000000000999
t =  742.0000000001002
t =  743.0000000001004
t =  744.0000000001006
t =  745.0000000001008
t =  746.0000000001011
t =  747.0000000001013
t =  748.0000000001015
t =  749.0000000001017
t =  750.000000000102
t =  751.0000000001022
t =  752.0000000001024
t =  753.0000000001027
t =  754.0000000001029
t =  755.0000000001031
t =  756.0000000001033
t =  757.0000000001036
t =  758.0000000001038
t =  759.000000000104
t =  760.0000000001043
t =  761.0000000001045
t =  762.0000000001047
t =  763.0000000001049
t =  764.0000000001052
t =  765.0000000001054
t =  766.0000000001056
t =  767.0000000001058
t =  768.0000000001061
t =  769.0000000001063
t =  770.0000000001065
t =  771.0000000001068
t =  772.000000000107
t =  773.0000000001072
t =  774.0000000001074
t =  775.0000000001077
t =  776.0000000001079
t =  777.0000000001081
t =  778.0000000001083
t =  779.0000000001086
t =  780.0000000001088
t =  781.000000000109
t =  782.0000000001093
t =  783.0000000001095
t =  784.0000000001097
t =  785.0000000001099
t =  786.0000000001102
t =  787.0000000001104
t =  788.0000000001106
t =  789.0000000001108
t =  790.0000000001111
t =  791.0000000001113
t =  792.0000000001115
t =  793.0000000001118
t =  794.000000000112
t =  795.0000000001122
t =  796.0000000001124
t =  797.0000000001127
t =  798.0000000001129
t =  799.0000000001131
t =  800.0000000001133
t =  801.0000000001136
t =  802.0000000001138
t =  803.000000000114
t =  804.0000000001143
t =  805.0000000001145
t =  806.0000000001147
t =  807.0000000001149
t =  808.0000000001152
t =  809.0000000001154
t =  810.0000000001156
t =  811.0000000001158
t =  812.0000000001161
t =  813.0000000001163
t =  814.0000000001165
t =  815.0000000001168
t =  816.000000000117
t =  817.0000000001172
t =  818.0000000001174
t =  819.0000000001177
t =  820.0000000001179
t =  821.0000000001181
t =  822.0000000001183
t =  823.0000000001186
t =  824.0000000001188
t =  825.000000000119
t =  826.0000000001193
t =  827.0000000001195
t =  828.0000000001197
t =  829.0000000001199
t =  830.0000000001202
t =  831.0000000001204
t =  832.0000000001206
t =  833.0000000001208
t =  834.0000000001211
t =  835.0000000001213
t =  836.0000000001215
t =  837.0000000001218
t =  838.000000000122
t =  839.0000000001222
t =  840.0000000001224
t =  841.0000000001227
t =  842.0000000001229
t =  843.0000000001231
t =  844.0000000001234
t =  845.0000000001236
t =  846.0000000001238
t =  847.000000000124
t =  848.0000000001243
t =  849.0000000001245
t =  850.0000000001247
t =  851.0000000001249
t =  852.0000000001252
t =  853.0000000001254
t =  854.0000000001256
t =  855.0000000001259
t =  856.0000000001261
t =  857.0000000001263
t =  858.0000000001265
t =  859.0000000001268
t =  860.000000000127
t =  861.0000000001272
t =  862.0000000001274
t =  863.0000000001277
t =  864.0000000001279
t =  865.0000000001281
t =  866.0000000001284
t =  867.0000000001286
t =  868.0000000001288
t =  869.000000000129
t =  870.0000000001293
t =  871.0000000001295
t =  872.0000000001297
t =  873.00000000013
t =  874.0000000001302
t =  875.0000000001304
t =  876.0000000001306
t =  877.0000000001309
t =  878.0000000001311
t =  879.0000000001313
t =  880.0000000001315
t =  881.0000000001318
t =  882.000000000132
t =  883.0000000001322
t =  884.0000000001324
t =  885.0000000001327
t =  886.0000000001329
t =  887.0000000001331
t =  888.0000000001334
t =  889.0000000001336
t =  890.0000000001338
t =  891.000000000134
t =  892.0000000001343
t =  893.0000000001345
t =  894.0000000001347
t =  895.000000000135
t =  896.0000000001352
t =  897.0000000001354
t =  898.0000000001356
t =  899.0000000001359
t =  900.0000000001361
t =  901.0000000001363
t =  902.0000000001365
t =  903.0000000001368
t =  904.000000000137
t =  905.0000000001372
t =  906.0000000001374
t =  907.0000000001377
t =  908.0000000001379
t =  909.0000000001381
t =  910.0000000001384
t =  911.0000000001386
t =  912.0000000001388
t =  913.000000000139
t =  914.0000000001393
t =  915.0000000001395
t =  916.0000000001397
t =  917.00000000014
t =  918.0000000001402
t =  919.0000000001404
t =  920.0000000001406
t =  921.0000000001409
t =  922.0000000001411
t =  923.0000000001413
t =  924.0000000001415
t =  925.0000000001418
t =  926.000000000142
t =  927.0000000001422
t =  928.0000000001424
t =  929.0000000001427
t =  930.0000000001429
t =  931.0000000001431
t =  932.0000000001434
t =  933.0000000001436
t =  934.0000000001438
t =  935.000000000144
t =  936.0000000001443
t =  937.0000000001445
t =  938.0000000001447
t =  939.000000000145
t =  940.0000000001452
t =  941.0000000001454
t =  942.0000000001456
t =  943.0000000001459
t =  944.0000000001461
t =  945.0000000001463
t =  946.0000000001465
t =  947.0000000001468
t =  948.000000000147
t =  949.0000000001472
t =  950.0000000001475
t =  951.0000000001477
t =  952.0000000001479
t =  953.0000000001481
t =  954.0000000001484
t =  955.0000000001486
t =  956.0000000001488
t =  957.000000000149
t =  958.0000000001493
t =  959.0000000001495
t =  960.0000000001497
t =  961.00000000015
t =  962.0000000001502
t =  963.0000000001504
t =  964.0000000001506
t =  965.0000000001509
t =  966.0000000001511
t =  967.0000000001513
t =  968.0000000001515
t =  969.0000000001518
t =  970.000000000152
t =  971.0000000001522
t =  972.0000000001525
t =  973.0000000001527
t =  974.0000000001529
t =  975.0000000001531
t =  976.0000000001534
t =  977.0000000001536
t =  978.0000000001538
t =  979.000000000154
t =  980.0000000001543
t =  981.0000000001545
t =  982.0000000001547
t =  983.000000000155
t =  984.0000000001552
t =  985.0000000001554
t =  986.0000000001556
t =  987.0000000001559
t =  988.0000000001561
t =  989.0000000001563
t =  990.0000000001565
t =  991.0000000001568
t =  992.000000000157
t =  993.0000000001572
t =  994.0000000001575
t =  995.0000000001577
t =  996.0000000001579
t =  997.0000000001581
t =  998.0000000001584
t =  999.0000000001586
t =  1000.0000000001588