日志

关于入射场，散射场和辐射场的思考

热度 1已有 873 次阅读2007-1-2 15:08 |个人分类:SYSNOISE

最近讨论入射场，散射场和辐射场的比较多，但是好像还不是很清晰。所以我做了下面两个算例，
希望大家指点。
计算模型是球壳，声源是平面波，它的参数如下：
Amplitude Real 1 Imag 0
Position 10 10 0
Vector -1 -1 0

第一种：考虑球壳与声的耦合作用。
第二种：不考虑耦合作用。

场点为半径为5的球场面。

下图为结果，在耦合的情况下，
计算类型：
Option BEM Direct Collocation Node Exterior Coupled Unbaffled NoAsymptotic Frequency Return
最后的场点压力应该包括三个部分：入射场＋辐射场＋散射场。
根据前面的一些帖子，已经知道：这时候如果去掉声源，在计算场点则得到的是辐射场的压力。

附件为模型网格文件和命令流。
cball.cmd

CODE:

New Model 1 File cball.sdb Return 
Option  BEM Direct Collocation Node Exterior Coupled Unbaffled NoAsymptotic Frequency  Return 
Import Mesh Format Patran File mesh.out Return 
Geometry Thickness 0.001 
    Elements All 
    Return 
Material Shell 
    Name 'steel' 
    Young 2.1e11  Poisson 0.3  Rho 7800 
    Elements all 
    Return 
Save Return 
Material Fluid 
    Sound Real 1500  Rho Real 1000 
    Return 
Save Return 
Source Name 'p' Plane 
    Amplitude Real 1 Imag 0 
    Position 10 10 0 
    Vector -1 -1 0 
    Return 
Solve 
    Frequency 20 To 100 LinStep 10 
    Return 
Save Return 
Point Sphere Radius 5 Divide 4 Return 
PostProcess 
    Points all 
    Frequency 20 To 100 LinStep 10 
    Near 2 
    Far 5 
    Quadrature 2 2 1 
    Save Results Step 1 
    Return 
Save Return 
Combine 
Read Point 85 Pressure Return 
Write Function File co.tbl Return 
Return 
Close Return

unball.cmd

CODE:

New Model 1 File unball.sdb Return 
Option  BEM Direct Collocation Node Exterior Uncoupled Unbaffled NoAsymptotic Frequency  Return 
Import Mesh Format Patran File mesh.out Return 
Save Return 
Material Fluid 
    Sound Real 1500  Rho Real 1000 
    Return 
Source Name 'p' Plane 
    Amplitude Real 1 Imag 0 
    Position 100 100 0 
    Vector -1 -1 0 
    Return 
Source Reset Return 
Source Name 'p' Plane 
    Amplitude Real 1 Imag 0 
    Position 10 10 0 
    Vector -1 -1 0 
    Return 
Solve 
    Frequency 20 To 100 LinStep 10 
    Return 
Save Return 
Point Sphere Radius 5 Divide 4 Return 
PostProcess 
    Points all 
    Frequency 20 To 100 LinStep 10 
    Near 2 
    Far 5 
    Quadrature 2 2 1 
    Save Results Step 1 
    Return 
Save Return 
Combine 
Read Point 85 Pressure Return 
Write Function File un.tbl Return 
Return 
Close Return

mesh.out

QUOTE:

25    0    0    1    0    0    0    0    0
P3/PATRAN Neutral File from: C:\WINNT\temp\ball.db
26    0    0    1    514    496    0    0    0
15--06    10:04:04       3.0
1    1    0    2    0    0    0    0    0
  1.000000000E+0  0.000000000E+0  0.000000000E+0
1G    6    0    0  000000
1    2    0    2    0    0    0    0    0
  9.807859063E-1  1.950871199E-1  0.000000000E+0
1G    6    0    0  000000
1    3    0    2    0    0    0    0    0
  9.238820076E-1  3.826774061E-1  0.000000000E+0
1G    6    0    0  000000
1    4    0    2    0    0    0    0    0
  8.314750791E-1  5.555620790E-1  0.000000000E+0
1G    6    0    0  000000
1    5    0    2    0    0    0    0    0
  7.071160078E-1  7.070975304E-1  0.000000000E+0
1G    6    0    0  000000
1    6    0    2    0    0    0    0    0
  5.555838346E-1  8.314605355E-1  0.000000000E+0
1G    6    0    0  000000
1    7    0    2    0    0    0    0    0
  3.827014863E-1  9.238720536E-1  0.000000000E+0
1G    6    0    0  000000
1    8    0    2    0    0    0    0    0
  1.951127797E-1  9.807808399E-1  0.000000000E+0
1G    6    0    0  000000
1    9    0    2    0    0    0    0    0
  9.795269370E-1  0.000000000E+0 -2.013131976E-1
1G    6    0    0  000000
1    10    0    2    0    0    0    0    0
  9.607065916E-1  1.950871199E-1 -1.974433511E-1
1G    6    0    0  000000
1    11    0    2    0    0    0    0    0
  9.049680233E-1  3.826774061E-1 -1.859862506E-1
1G    6    0    0  000000
1    12    0    2    0    0    0    0    0
  8.144531250E-1  5.555620790E-1 -1.673823297E-1
1G    6    0    0  000000
1    13    0    2    0    0    0    0    0
  6.926402450E-1  7.070975304E-1 -1.423466057E-1
1G    6    0    0  000000
1    14    0    2    0    0    0    0    0
  5.442103744E-1  8.314605355E-1 -1.118412614E-1
1G    6    0    0  000000
1    15    0    2    0    0    0    0    0
  3.748672605E-1  9.238720536E-1 -7.703864574E-2
1G    6    0    0  000000
1    16    0    2    0    0    0    0    0
  1.911187321E-1  9.807808399E-1 -3.927627206E-2
1G    6    0    0  000000
1    17    0    2    0    0    0    0    0
  9.189509153E-1  0.000000000E+0 -3.943719864E-1
1G    6    0    0  000000
1    18    0    2    0    0    0    0    0
  9.012949467E-1  1.950871199E-1 -3.867925107E-1
1G    6    0    0  000000
1    19    0    2    0    0    0    0    0
  8.490037918E-1  3.826774061E-1 -3.643494546E-1
1G    6    0    0  000000
1    20    0    2    0    0    0    0    0
  7.640869021E-1  5.555620790E-1 -3.279054165E-1
1G    6    0    0  000000
1    21    0    2    0    0    0    0    0
  6.498073339E-1  7.070975304E-1 -2.788610756E-1
1G    6    0    0  000000
1    22    0    2    0    0    0    0    0
  5.105566382E-1  8.314605355E-1 -2.191011012E-1
1G    6    0    0  000000
1    23    0    2    0    0    0    0    0
  3.516858518E-1  9.238720536E-1 -1.509221196E-1
1G    6    0    0  000000
1    24    0    2    0    0    0    0    0
  1.793002486E-1  9.807808399E-1 -7.694426179E-2
1G    6    0    0  000000
1    25    0    2    0    0    0    0    0
  8.207520247E-1  0.000000000E+0 -5.712845922E-1
1G    6    0    0  000000
1    26    0    2    0    0    0    0    0
  8.049834371E-1  1.950871199E-1 -5.603058934E-1
1G    6    0    0  000000
1    27    0    2    0    0    0    0    0
  7.582806945E-1  3.826774061E-1 -5.277957916E-1
1G    6    0    0  000000
1    28    0    2    0    0    0    0    0
  6.824383736E-1  5.555620790E-1 -4.750038087E-1
1G    6    0    0  000000
1    29    0    2    0    0    0    0    0
  5.803709626E-1  7.070975304E-1 -4.039587379E-1
1G    6    0    0  000000
1    30    0    2    0    0    0    0    0
  4.560005367E-1  8.314605355E-1 -3.173907995E-1
1G    6    0    0  000000
1    31    0    2    0    0    0    0    0
  3.141062856E-1  9.238720536E-1 -2.186267674E-1
1G    6    0    0  000000
1    32    0    2    0    0    0    0    0
  1.601411551E-1  9.807808399E-1 -1.114621311E-1
1G    6    0    0  000000
1    33    0    2    0    0    0    0    0
  6.889506578E-1  0.000000000E+0 -7.248082757E-1
1G    6    0    0  000000
1    34    0    2    0    0    0    0    0
  6.757150888E-1  1.950871199E-1 -7.108798623E-1
1G    6    0    0  000000
1    35    0    2    0    0    0    0    0
  6.365128756E-1  3.826774061E-1 -6.696337461E-1
1G    6    0    0  000000
1    36    0    2    0    0    0    0    0
  5.728503466E-1  5.555620790E-1 -6.026551723E-1
1G    6    0    0  000000
1    37    0    2    0    0    0    0    0
  4.871737957E-1  7.070975304E-1 -5.125180483E-1
1G    6    0    0  000000
1    38    0    2    0    0    0    0    0
  3.827754855E-1  8.314605355E-1 -4.026863873E-1
1G    6    0    0  000000
1    39    0    2    0    0    0    0    0
  2.636671066E-1  9.238720536E-1 -2.773807645E-1
1G    6    0    0  000000
1    40    0    2    0    0    0    0    0
  1.344258487E-1  9.807808399E-1 -1.414167136E-1
1G    6    0    0  000000
1    41    0    2    0    0    0    0    0
  5.289428234E-1  0.000000000E+0 -8.486574888E-1
1G    6    0    0  000000
1    42    0    2    0    0    0    0    0
  5.187821984E-1  1.950871199E-1 -8.323497176E-1
1G    6    0    0  000000
1    43    0    2    0    0    0    0    0
  4.886856675E-1  3.826774061E-1 -7.840563059E-1
1G    6    0    0  000000
1    44    0    2    0    0    0    0    0
  4.398093522E-1  5.555620790E-1 -7.056334019E-1
1G    6    0    0  000000
1    45    0    2    0    0    0    0    0
  3.740313947E-1  7.070975304E-1 -6.000946760E-1
1G    6    0    0  000000
1    46    0    2    0    0    0    0    0
  2.938794494E-1  8.314605355E-1 -4.714957774E-1
1G    6    0    0  000000
1    47    0    2    0    0    0    0    0
  2.024332732E-1  9.238720536E-1 -3.247786760E-1
1G    6    0    0  000000
1    48    0    2    0    0    0    0    0
  1.032071263E-1  9.807808399E-1 -1.655816585E-1
1G    6    0    0  000000
1    49    0    2    0    0    0    0    0
  3.472794294E-1  0.000000000E+0 -9.377616644E-1
1G    6    0    0  000000
1    50    0    2    0    0    0    0    0
  3.406099677E-1  1.950871199E-1 -9.197422862E-1
1G    6    0    0  000000
1    51    0    2    0    0    0    0    0
  3.208511472E-1  3.826774061E-1 -8.663789630E-1
1G    6    0    0  000000
1    52    0    2    0    0    0    0    0
  2.887622416E-1  5.555620790E-1 -7.797225118E-1
1G    6    0    0  000000
1    53    0    2    0    0    0    0    0
  2.455759943E-1  7.070975304E-1 -6.631029248E-1
1G    6    0    0  000000
1    54    0    2    0    0    0    0    0
  1.929518133E-1  8.314605355E-1 -5.210019350E-1
1G    6    0    0  000000
1    55    0    2    0    0    0    0    0
  1.329117417E-1  9.238720536E-1 -3.588800430E-1
1G    6    0    0  000000
1    56    0    2    0    0    0    0    0
  6.776306033E-2  9.807808399E-1 -1.829676628E-1
1G    6    0    0  000000
1    57    0    2    0    0    0    0    0
  1.513980776E-1  0.000000000E+0 -9.884728789E-1
1G    6    0    0  000000
1    58    0    2    0    0    0    0    0
  1.484927237E-1  1.950871199E-1 -9.694797397E-1
1G    6    0    0  000000
1    59    0    2    0    0    0    0    0
  1.398807913E-1  3.826774061E-1 -9.132312536E-1
1G    6    0    0  000000
1    60    0    2    0    0    0    0    0
  1.258929521E-1  5.555620790E-1 -8.218891621E-1
1G    6    0    0  000000
1    61    0    2    0    0    0    0    0
  1.070664749E-1  7.070975304E-1 -6.989634037E-1
1G    6    0    0  000000
1    62    0    2    0    0    0    0    0
  8.412465453E-2  8.314605355E-1 -5.491779447E-1
1G    6    0    0  000000
1    63    0    2    0    0    0    0    0
  5.794880167E-2  9.238720536E-1 -3.782887161E-1
1G    6    0    0  000000
1    64    0    2    0    0    0    0    0
  2.954477258E-2  9.807808399E-1 -1.928629130E-1
1G    6    0    0  000000
1    65    0    2    0    0    0    0    0
-5.068170652E-2  0.000000000E+0 -9.987148643E-1
1G    6    0    0  000000
1    66    0    2    0    0    0    0    0
-4.970386997E-2  1.950871199E-1 -9.795256853E-1
1G    6    0    0  000000
1    67    0    2    0    0    0    0    0
-4.681648687E-2  3.826774061E-1 -9.226951003E-1
1G    6    0    0  000000
1    68    0    2    0    0    0    0    0
-4.213046655E-2  5.555620790E-1 -8.304070234E-1
1G    6    0    0  000000
1    69    0    2    0    0    0    0    0
-3.582634032E-2  7.070975304E-1 -7.062078714E-1
1G    6    0    0  000000
1    70    0    2    0    0    0    0    0
-2.814661153E-2  8.314605355E-1 -5.548704267E-1
1G    6    0    0  000000
1    71    0    2    0    0    0    0    0
-1.938666031E-2  9.238720536E-1 -3.822101355E-1
1G    6    0    0  000000
1    72    0    2    0    0    0    0    0
-9.883102030E-3  9.807808399E-1 -1.948623210E-1
1G    6    0    0  000000
1    73    0    2    0    0    0    0    0
-2.506864369E-1  0.000000000E+0 -9.680683613E-1
1G    6    0    0  000000
1    74    0    2    0    0    0    0    0
-2.458656281E-1  1.950871199E-1 -9.494688511E-1
1G    6    0    0  000000
1    75    0    2    0    0    0    0    0
-2.315968126E-1  3.826774061E-1 -8.943829536E-1
1G    6    0    0  000000
1    76    0    2    0    0    0    0    0
-2.084289640E-1  5.555620790E-1 -8.049274087E-1
1G    6    0    0  000000
1    77    0    2    0    0    0    0    0
-1.772524714E-1  7.070975304E-1 -6.845397353E-1
1G    6    0    0  000000
1    78    0    2    0    0    0    0    0
-1.392655373E-1  8.314605355E-1 -5.378461480E-1
1G    6    0    0  000000
1    79    0    2    0    0    0    0    0
-9.592835605E-2  9.238720536E-1 -3.704836965E-1
1G    6    0    0  000000
1    80    0    2    0    0    0    0    0
-4.890632629E-2  9.807808399E-1 -1.888840050E-1
1G    6    0    0  000000
1    81    0    2    0    0    0    0    0
-4.404277802E-1  0.000000000E+0 -8.977880478E-1
1G    6    0    0  000000
1    82    0    2    0    0    0    0    0
-4.319612384E-1  1.950871199E-1 -8.805398941E-1
1G    6    0    0  000000
1    83    0    2    0    0    0    0    0
-4.068955481E-1  3.826774061E-1 -8.294540644E-1
1G    6    0    0  000000
1    84    0    2    0    0    0    0    0
-3.661942184E-1  5.555620790E-1 -7.464935184E-1
1G    6    0    0  000000
1    85    0    2    0    0    0    0    0
-3.114216626E-1  7.070975304E-1 -6.348461509E-1
1G    6    0    0  000000
1    86    0    2    0    0    0    0    0
-2.446828783E-1  8.314605355E-1 -4.988022447E-1
1G    6    0    0  000000
1    87    0    2    0    0    0    0    0
-1.685427129E-1  9.238720536E-1 -3.435895443E-1
1G    6    0    0  000000
1    88    0    2    0    0    0    0    0
-8.592734486E-2  9.807808399E-1 -1.751727462E-1
1G    6    0    0  000000
1    89    0    2    0    0    0    0    0
-6.121373773E-1  0.000000000E+0 -7.907514572E-1
1G    6    0    0  000000
1    90    0    2    0    0    0    0    0
-6.003719568E-1  1.950871199E-1 -7.755607963E-1
1G    6    0    0  000000
1    91    0    2    0    0    0    0    0
-5.655354857E-1  3.826774061E-1 -7.305666804E-1
1G    6    0    0  000000
1    92    0    2    0    0    0    0    0
-5.089672208E-1  5.555620790E-1 -6.574976444E-1
1G    6    0    0  000000
1    93    0    2    0    0    0    0    0
-4.328410625E-1  7.070975304E-1 -5.591616035E-1
1G    6    0    0  000000
1    94    0    2    0    0    0    0    0
-3.400827646E-1  8.314605355E-1 -4.393371344E-1
1G    6    0    0  000000
1    95    0    2    0    0    0    0    0
-2.342568636E-1  9.238720536E-1 -3.026287258E-1
1G    6    0    0  000000
1    96    0    2    0    0    0    0    0
-1.194304824E-1  9.807808399E-1 -1.542898566E-1
1G    6    0    0  000000
1    97    0    2    0    0    0    0    0
-7.587856650E-1  0.000000000E+0 -6.513403654E-1
1G    6    0    0  000000
1    98    0    2    0    0    0    0    0
-7.442029715E-1  1.950871199E-1 -6.388293505E-1
1G    6    0    0  000000
1    99    0    2    0    0    0    0    0
-7.010221481E-1  3.826774061E-1 -6.017690301E-1
1G    6    0    0  000000
1    100    0    2    0    0    0    0    0
-6.309027672E-1  5.555620790E-1 -5.415832996E-1
1G    6    0    0  000000
1    101    0    2    0    0    0    0    0
-5.365397930E-1  7.070975304E-1 -4.605845809E-1
1G    6    0    0  000000
1    102    0    2    0    0    0    0    0
-4.215595126E-1  8.314605355E-1 -3.618853092E-1
1G    6    0    0  000000
1    103    0    2    0    0    0    0    0
-2.903805077E-1  9.238720536E-1 -2.492781132E-1
1G    6    0    0  000000
1    104    0    2    0    0    0    0    0
-1.480440795E-1  9.807808399E-1 -1.270903200E-1
1G    6    0    0  000000
1    105    0    2    0    0    0    0    0
-8.743684888E-1  0.000000000E+0 -4.852625132E-1
1G    6    0    0  000000
1    106    0    2    0    0    0    0    0
-8.575656414E-1  1.950871199E-1 -4.759434462E-1
1G    6    0    0  000000
1    107    0    2    0    0    0    0    0
-8.078083396E-1  3.826774061E-1 -4.483343959E-1
1G    6    0    0  000000
1    108    0    2    0    0    0    0    0
-7.270088196E-1  5.555620790E-1 -4.034959376E-1
1G    6    0    0  000000
1    109    0    2    0    0    0    0    0
-6.182723045E-1  7.070975304E-1 -3.431507945E-1
1G    6    0    0  000000
1    110    0    2    0    0    0    0    0
-4.857773781E-1  8.314605355E-1 -2.696177363E-1
1G    6    0    0  000000
1    111    0    2    0    0    0    0    0
-3.346158266E-1  9.238720536E-1 -1.857220232E-1
1G    6    0    0  000000
1    112    0    2    0    0    0    0    0
-1.705967337E-1  9.807808399E-1 -9.468765557E-2
1G    6    0    0  000000
1    113    0    2    0    0    0    0    0
-9.541534185E-1  0.000000000E+0 -2.993179262E-1
1G    6    0    0  000000
1    114    0    2    0    0    0    0    0
-9.358184934E-1  1.950871199E-1 -2.935724258E-1
1G    6    0    0  000000
1    115    0    2    0    0    0    0    0
-8.815219402E-1  3.826774061E-1 -2.765448391E-1
1G    6    0    0  000000
1    116    0    2    0    0    0    0    0
-7.933503389E-1  5.555620790E-1 -2.488895059E-1
1G    6    0    0  000000
1    117    0    2    0    0    0    0    0
-6.746922135E-1  7.070975304E-1 -2.116684169E-1
1G    6    0    0  000000
1    118    0    2    0    0    0    0    0
-5.301073194E-1  8.314605355E-1 -1.663118899E-1
1G    6    0    0  000000
1    119    0    2    0    0    0    0    0
-3.651518524E-1  9.238720536E-1 -1.145624071E-1
1G    6    0    0  000000
1    120    0    2    0    0    0    0    0
-1.861651093E-1  9.807808399E-1 -5.840845779E-2
1G    6    0    0  000000
1    121    0    2    0    0    0    0    0
-9.948743582E-1  0.000000000E+0 -1.011185870E-1
1G    6    0    0  000000
1    122    0    2    0    0    0    0    0
-9.757581949E-1  1.950871199E-1 -9.918171912E-2
1G    6    0    0  000000
1    123    0    2    0    0    0    0    0
-9.191454053E-1  3.826774061E-1 -9.343317896E-2
1G    6    0    0  000000
1    124    0    2    0    0    0    0    0
-8.272116780E-1  5.555620790E-1 -8.409307152E-2
1G    6    0    0  000000
1    125    0    2    0    0    0    0    0
-7.034898400E-1  7.070975304E-1 -7.152009755E-2
1G    6    0    0  000000
1    126    0    2    0    0    0    0    0
-5.527343750E-1  8.314605355E-1 -5.619713664E-2
1G    6    0    0  000000
1    127    0    2    0    0    0    0    0
-3.807384372E-1  9.238720536E-1 -3.871249035E-2
1G    6    0    0  000000
1    128    0    2    0    0    0    0    0
-1.941118389E-1  9.807808399E-1 -1.973803528E-2
1G    6    0    0  000000
1    129    0    2    0    0    0    0    0
-9.948640466E-1  0.000000000E+0  1.012204811E-1
1G    6    0    0  000000
1    130    0    2    0    0    0    0    0
-9.757492542E-1  1.950871199E-1  9.926940501E-2
1G    6    0    0  000000
1    131    0    2    0    0    0    0    0
-9.191381931E-1  3.826774061E-1  9.350372851E-2
1G    6    0    0  000000
1    132    0    2    0    0    0    0    0
-8.272062540E-1  5.555620790E-1  8.414619416E-2
1G    6    0    0  000000
1    133    0    2    0    0    0    0    0
-7.034862041E-1  7.070975304E-1  7.155618072E-2
1G    6    0    0  000000
1    134    0    2    0    0    0    0    0
-5.527321696E-1  8.314605355E-1  5.621845275E-2
1G    6    0    0  000000
1    135    0    2    0    0    0    0    0
-3.807374537E-1  9.238720536E-1  3.872225434E-2
1G    6    0    0  000000
1    136    0    2    0    0    0    0    0
-1.941115856E-1  9.807808399E-1  1.974054053E-2
1G    6    0    0  000000
1    137    0    2    0    0    0    0    0
-9.541227221E-1  0.000000000E+0  2.994158268E-1
1G    6    0    0  000000
1    138    0    2    0    0    0    0    0
-9.357920885E-1  1.950871199E-1  2.936565280E-1
1G    6    0    0  000000
1    139    0    2    0    0    0    0    0
-8.815006614E-1  3.826774061E-1  2.766126692E-1
1G    6    0    0  000000
1    140    0    2    0    0    0    0    0
-7.933343649E-1  5.555620790E-1  2.489404529E-1
1G    6    0    0  000000
1    141    0    2    0    0    0    0    0
-6.746812463E-1  7.070975304E-1  2.117032856E-1
1G    6    0    0  000000
1    142    0    2    0    0    0    0    0
-5.301008821E-1  8.314605355E-1  1.663323194E-1
1G    6    0    0  000000
1    143    0    2    0    0    0    0    0
-3.651489019E-1  9.238720536E-1  1.145718396E-1
1G    6    0    0  000000
1    144    0    2    0    0    0    0    0
-1.861643642E-1  9.807808399E-1  5.841086060E-2
1G    6    0    0  000000
1    145    0    2    0    0    0    0    0
-8.743185997E-1  0.000000000E+0  4.853523970E-1
1G    6    0    0  000000
1    146    0    2    0    0    0    0    0
-8.575227857E-1  1.950871199E-1  4.760206938E-1
1G    6    0    0  000000
1    147    0    2    0    0    0    0    0
-8.077736497E-1  3.826774061E-1  4.483968616E-1
1G    6    0    0  000000
1    148    0    2    0    0    0    0    0
-7.269828916E-1  5.555620790E-1  4.035426080E-1
1G    6    0    0  000000
1    149    0    2    0    0    0    0    0
-6.182546020E-1  7.070975304E-1  3.431826234E-1
1G    6    0    0  000000
1    150    0    2    0    0    0    0    0
-4.857669771E-1  8.314605355E-1  2.696364820E-1
1G    6    0 &nbs