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-   -   Strange residuals trend (http://www.cfd-online.com/Forums/su2/118795-strange-residuals-trend.html)

robyTKD June 4, 2013 10:53

Strange residuals trend
 
Hi developers,

running a direct simulation on a subsonic case I found a strange trend of the residuals as you can see below:

Code:

TITLE = "SU2 Simulation"
VARIABLES = "Iteration","CLift","CDrag","CSideForce","CMx","CMy","CMz","CFx","CFy","CFz","CL/CD","Res_Flow[0]","Res_Flow[1]","Res_Flow[2]","Res_Flow[3]","Res_Flow[4]","Res_Turb[0]","Linear_Solver_Iterations","Time(min)"
ZONE T= "Convergence history"
...
        7904, 0.2578906743, 0.0092747485, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057006271, 0.0002688439, 0.2580572583, 0.0000000000, 27.8056783402, -5.3620574586, -2.0099686806, -3.7912108836, 0.1793780325, 0.0000000000, -4.9291935971, 67.0000000000, 302.9638412167
        7905, 0.2578905668, 0.0092747235, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057006062, 0.0002688226, 0.2580571500, 0.0000000000, 27.8057418847, -5.3620666353, -2.0099773734, -3.7912080048, 0.1793694593, 0.0000000000, -4.9291990197, 55.0000000000, 302.9937163667
        7906, 0.2578904593, 0.0092746984, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057005853, 0.0002688013, 0.2580570417, 0.0000000000, 27.8058054211, -5.3620758134, -2.0099860664, -3.7912051029, 0.1793608844, 0.0000000000, -4.9292044397, 78.0000000000, 303.0319785833
        7907, 0.2578903518, 0.0092746734, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057005644, 0.0002687800, 0.2580569334, 0.0000000000, 27.8058689490, -5.3620849934, -2.0099947595, -3.7912021875, 0.1793523075, 0.0000000000, -4.9292098573, 74.0000000000, 303.0682667000
        7908, 0.2578902444, 0.0092746483, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057005435, 0.0002687587, 0.2580568252, 0.0000000000, 27.8059324686, -5.3620941753, -2.0100034530, -3.7911992570, 0.1793437287, 0.0000000000, -4.9292152724, 57.0000000000, 303.0979531333
        7909, 0.2578901370, 0.0092746233, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057005226, 0.0002687374, 0.2580567169, 0.0000000000, 27.8059959801, -5.3621033589, -2.0100121468, -3.7911963053, 0.1793351477, 0.0000000000, -4.9292206850, 88.0000000000, 303.1407903167
        7910, 0.2578900296, 0.0092745982, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057005017, 0.0002687161, 0.2580566087, 0.0000000000, 27.8060594831, -5.3621125444, -2.0100208407, -3.7911933367, 0.1793265651, 0.0000000000, -4.9292260952, 53.0000000000, 303.1691070000
        7911, 0.2578899222, 0.0092745732, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057004808, 0.0002686949, 0.2580565005, 0.0000000000, 27.8061229780, -5.3621217317, -2.0100295350, -3.7911903505, 0.1793179803, 0.0000000000, -4.9292315029, 68.0000000000, 303.2028496500
        7912, 0.2578898148, 0.0092745481, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057004599, 0.0002686736, 0.2580563924, 0.0000000000, 27.8061864645, -5.3621309213, -2.0100382295, -3.7911873473, 0.1793093935, 0.0000000000, -4.9292369082, 53.0000000000, 303.2311020333
        7913, 0.2578897075, 0.0092745231, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057004390, 0.0002686523, 0.2580562843, 0.0000000000, 27.8062499430, -5.3621401128, -2.0100469244, -3.7911843312, 0.1793008048, 0.0000000000, -4.9292423111, 74.0000000000, 303.2726971000
        7914, 0.2578896002, 0.0092744981, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057004182, 0.0002686310, 0.2580561761, 0.0000000000, 27.8063134131, -5.3621493062, -2.0100556194, -3.7911812926, 0.1792922144, 0.0000000000, -4.9292477117, 79.0000000000, 303.3170581500
        7915, 0.2578894929, 0.0092744730, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003973, 0.0002686098, 0.2580560680, 0.0000000000, 27.8063768750, -5.3621585022, -2.0100643148, -3.7911782495, 0.1792836217, 0.0000000000, -4.9292531099, 66.0000000000, 303.3513538000
        7916, 0.2578893857, 0.0092744480, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003764, 0.0002685885, 0.2580559600, 0.0000000000, 27.8064403289, -5.3621676998, -2.0100730105, -3.7911751815, 0.1792750272, 0.0000000000, -4.9292585059, 79.0000000000, 303.3907992333
        7917, 0.2578892784, 0.0092744230, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003556, 0.0002685673, 0.2580558519, 0.0000000000, 27.8065037749, -5.3621769004, -2.0100817064, -3.7911721109, 0.1792664304, 0.0000000000, -4.9292638995, 73.0000000000, 303.4277142000
        7918, 0.2578891712, 0.0092743980, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003347, 0.0002685460, 0.2580557439, 0.0000000000, 27.8065672129, -5.3621861029, -2.0100904027, -3.7911690165, 0.1792578319, 0.0000000000, -4.9292692908, 58.0000000000, 303.4577453833
        7919, 0.2578890640, 0.0092743730, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003138, 0.0002685247, 0.2580556359, 0.0000000000, 27.8066306430, -5.3621953078, -2.0100990995, -3.7911659169, 0.1792492310, 0.0000000000, -16.0000000000, 100.0000000000, 303.5082288667
        7920, 0.2578890640, 0.0092743730, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003138, 0.0002685247, 0.2580556359, 0.0000000000, 27.8066306430, -5.3621953078, -16.0000000000, -16.0000000000, -16.0000000000, 0.0000000000, -16.0000000000, 100.0000000000, 303.5599338500
        7921, 0.2578890640, 0.0092743730, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003138, 0.0002685247, 0.2580556359, 0.0000000000, 27.8066306430, -5.3621953078, -16.0000000000, -16.0000000000, -16.0000000000, 0.0000000000, -16.0000000000, 100.0000000000, 303.6111823167
        7922, 0.2578890640, 0.0092743730, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003138, 0.0002685247, 0.2580556359, 0.0000000000, 27.8066306430, -5.3621953078, -16.0000000000, -16.0000000000, -16.0000000000, 0.0000000000, -16.0000000000, 100.0000000000, 303.6623054833
        7923, 0.2578890640, 0.0092743730, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003138, 0.0002685247, 0.2580556359, 0.0000000000, 27.8066306430, -5.3621953078, -16.0000000000, -16.0000000000, -16.0000000000, 0.0000000000, -16.0000000000, 100.0000000000, 303.7136734000
        7924, 0.2578890640, 0.0092743730, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003138, 0.0002685247, 0.2580556359, 0.0000000000, 27.8066306430, -5.3621953078, -16.0000000000, -16.0000000000, -16.0000000000, 0.0000000000, -16.0000000000, 100.0000000000, 303.7653447167
        7925, 0.2578890640, 0.0092743730, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003138, 0.0002685247, 0.2580556359, 0.0000000000, 27.8066306430, -5.3621953078, -16.0000000000, -16.0000000000, -16.0000000000, 0.0000000000, -16.0000000000, 100.0000000000, 303.8160094333
        7926, 0.2578890640, 0.0092743730, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003138, 0.0002685247, 0.2580556359, 0.0000000000, 27.8066306430, -5.3621953078, -16.0000000000, -16.0000000000, -16.0000000000, 0.0000000000, -16.0000000000, 100.0000000000, 303.8676317333
        7927, 0.2578890640, 0.0092743730, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003138, 0.0002685247, 0.2580556359, 0.0000000000, 27.8066306430, -5.3621953078, -16.0000000000, -16.0000000000, -16.0000000000, 0.0000000000, -16.0000000000, 100.0000000000, 303.9190650167
        7928, 0.2578890640, 0.0092743730, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003138, 0.0002685247, 0.2580556359, 0.0000000000, 27.8066306430, -5.3621953078, -16.0000000000, -16.0000000000, -16.0000000000, 0.0000000000, -16.0000000000, 100.0000000000, 303.9698802500
        7929, 0.2578890640, 0.0092743730, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003138, 0.0002685247, 0.2580556359, 0.0000000000, 27.8066306430, -5.3621953078, -16.0000000000, -16.0000000000, -16.0000000000, 0.0000000000, -16.0000000000, 100.0000000000, 304.0220018833
        7930, 0.2578890640, 0.0092743730, 0.0000000000, 0.0000000000, 0.0000000000, 0.0057003138, 0.0002685247, 0.2580556359, 0.0000000000, 27.8066306430, -5.3621953078, -16.0000000000, -16.0000000000, -16.0000000000, 0.0000000000, -16.0000000000, 100.0000000000, 304.0725622833
...

Please see columns referred to Res_Turb[0], Res_Flow[1], Res_Flow[2], Res_Flow[3].
For more clarity the case is the following:
  • NACA0012
  • M = 0.5
  • AoA = 2 deg
  • Re = 6E6
  • SA turbulent model

rktchip June 13, 2013 16:07

roby have you sorted this out?
- trent

robyTKD June 17, 2013 08:01

Hi Trent,

I meet this problem when using a second order scheme without limiter or, in some cases, using multigrid.

rktchip June 19, 2013 13:53

kk can you post your config file?


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