4. 例. 二層標的のクレータリング

強度の異なるターゲットへの衝突がクレーター形成過程に及ぼす影響

2層標的の例として,地球環境における海洋衝突を計算した.

条件は下記の通り.

  • 衝突天体サイズ:1 km
  • 衝突速度:15 km/s
  • ターゲット層物質:水,炭酸塩岩
  • 水層の厚さ:100 m, 200 m, 500 m, 1000 m

innput file例

asteroid.inp

#ISINP
------------------------------------------------------------------------
--- this is the new input file used by iSALE versions of v7.0 and higher
------------------------------------------------------------------------
------------------- General Model Info ---------------------------------
VERSION               __DO NOT MODIFY__             : 4.1
DIMENSION             dimension of input file       : 2
PATH                  Data file path                : ./
MODEL                 Modelname                     : 2layers_earth
------------------- Mesh Geometry Parameters ---------------------------
GRIDH                 horizontal cells              : 0           : 500         : 60
GRIDV                 vertical cells                : 60          : 500         : 60
GRIDEXT               ext. factor                   : 1.05d0
GRIDSPC               grid spacing                  : 2.5D0
CYL                   Cylind. geometry              : 1.0D0
GRIDSPCM              max. grid spacing             : -20.D0
------------------- Global setup parameters -----------------------------
S_TYPE                setup type                    : DEFAULT
T_SURF                Surface temp                  : 293.D0
GRAV_V                gravity                       : -9.81D0
------------------- Projectile ("Object") Parameters --------------------
OBJNUM                number of objects             : 1
OBJRESH               CPPR horizontal               : 20
OBJVEL                object velocity               : -1.5D4
OBJMAT                object material               : granite
OBJTYPE               object type                   : SPHEROID
------------------- Target Parameters ----------------------------------
LAYNUM                layers number                 : 2
LAYPOS                layer position                : 410          : 450
LAYMAT                layer material                : calcite      : water__
LAYTPROF              thermal profile               : CONST        : CONST 
------------------- Time Parameters ------------------------------------
DT                    initial time increment        : 5.0D-3
DTMAX                 maximum timestep              : 5.D-2
TEND                  end time                      : 1.00D2 
DTSAVE                save interval                 : 1.D-2
------------------- Ac. Fluid. Parameters (see also material.inp) ------
--TOFF                  toff                          : 16.D0
--CVIB                  c_vib                         : 0.1D0
--VIB_MAX               Max. vib.vel.                 : 200.
------------------- Boundary Condition Parameters ----------------------
--------------- 0=no slip,1=free slip, 2=cont.outflow ------------------
BND_L                 left                          : FREESLIP
BND_R                 right                         : FREESLIP
BND_B                 bottom                        : NOSLIP
BND_T                 top                           : OUTFLOW
------------------- Numerical Stability Parameters ---------------------
AVIS                  art. visc. linear             : 0.24D0
AVIS2                 art. visc. quad.              : 1.20D0
------------------- Tracer Particle Parameters -------------------------
--- if TR_SAVE == 1, only Trx and Try are automatically added to
--- the variable list. If additional variables shall be calculated
--- and stored, you have to set them in 'Tracer fields'.
-------- TR_NX/NY is the number of tracers in x/y-direction
-------  TR_DX/DY is the interval between tracers (usually the same as dx/dy)
TR_QUAL               integration qual.             : 1
TR_SPCH               tracer spacing X              : -2.D0       : -2.D0       : -2.D0
TR_SPCV               tracer spacing Y              : -2.D0       : -2.D0       : -2.D0
TR_VAR                add. tracer fiels             : #TrP-TrT#
------------------- Control parameters (global) ------------------------
STRESS                Consider stress               : 1
------------------- Data Saving Parameters -----------------------------
QUALITY               Compression rate              : 80
VARLIST               List of variables             : #Den-Tmp-Pre-Sie-Yld-YAc-Dam-VEL#
------------------------------------------------------------------------
<<END

material.inp

#ISMAT ! iSale material input file identification string
-----------------------------------------------------------------------------
MATNAME    Material name          : granite      : calcite      : water__
EOSNAME    EOS name               : granit2      : calcite      : water__
EOSTYPE    EOS type               : aneos        : aneos        : tillo
STRMOD     Strength model         : ROCK         : ROCK         : HYDRO
DAMMOD     Damage model           : IVANOV       : IVANOV       : NONE
ACFL       Acoustic fluidisation  : BLOCK        : BLOCK        : NONE
PORMOD     Porosity model         : NONE         : NONE         : NONE
THSOFT     Thermal softening      : OHNAKA       : OHNAKA       : NONE
LDWEAK     Low density weakening  : POLY         : POLY         : NONE
----------------------------------------------------------------------------
POIS       pois                   : 3.0000D-01   : 3.0000D-01   : 5.0000D-01
----------------------------------------------------------------------------
TMELT0     tmelt0                 : 1.6730D+03   : 1.5000D+03   : xxxxxxxxxx
CHEAT      C_heat                 : 1.0000D+03   : 1.0000D+03   : 1.0000D+03
TFRAC      tfrac                  : 1.2000D+00   : 1.2000D+00   : xxxxxxxxxx
ASIMON     a_simon                : 6.0000D+09   : 6.0000D+09   : xxxxxxxxxx
CSIMON     c_simon                : 3.0000D+00   : 3.0000D+00   : xxxxxxxxxx
----------------------------------------------------------------------------
YDAM0      ydam0 (ycoh)           : 1.0000D+04   : 1.0000D+04   : xxxxxxxxxx
FRICDAM    fricdam                : 6.0000D-01   : 4.0000D-01   : xxxxxxxxxx
YLIMDAM    ylimdam                : 2.5000D+09   : 5.0000D+08   : xxxxxxxxxx
----------------------------------------------------------------------------
YINT0      yint0                  : 1.0000D+07   : 5.0000D+06   : xxxxxxxxxx
FRICINT    fricint                : 2.0000D+00   : 1.0000D+00   : xxxxxxxxxx
YLIMINT    ylimint                : 2.5000D+09   : 5.0000D+08   : xxxxxxxxxx
----------------------------------------------------------------------------
IVANOV_A   Damage parameter       : 1.0000D-04   : 1.0000D-04   : xxxxxxxxxx
IVANOV_B   Damage parameter       : 1.0000D-11   : 1.0000D-11   : xxxxxxxxxx
IVANOV_C   Damage parameter       : 3.0000D+08   : 3.0000D+08   : xxxxxxxxxx
----------------------------------------------------------------------------
GAMETA     gam_eta                : 8.0000D-03   : 0.0000D-03   : xxxxxxxxxx
GAMBETA    gam_beta               : 1.1500D+02   : 0.0000D+02   : xxxxxxxxxx
----------------------------------------------------------------------------
VISC       viscosity              : xxxxxxxxxx   : xxxxxxxxxx   : 0.0000D+00
----------------------------------------------------------------------------
<<END ! used to identify the end of this file

計算結果

いくつかの特徴的なキャビティ成長の静止画(.png)と動画(.gif)を次に示す.

  • 左:密度,右:温度

水深100 m

wat100_00000.png wat100_00400.png wat100_00600.png wat_car_100.gif

水深200 m

wat200_00000.png wat200_00400.png wat200_00600.png wat_car_200.gif

水深500 m

wat500_00000.png wat500_00400.png wat500_00600.png wat_car_500.gif

水深1000 m

wat1000_00000.png wat1000_00400.png wat1000_00600.png wat_car_1000.gif

コメント

  • 水深が衝突体天体サイズと同程度 (100 m)
    • 一層ターゲットの場合と類似
  • 水深が衝突体天体サイズの2倍 (200 m)
    • 水と炭酸塩岩のキャビティの成長が異なる
    • 水層:垂直なイジェクタカーテン
    • 炭酸塩岩層:水のキャビティの成長後に遅れて炭酸塩岩層のイジェクタカーテンの広がりとともにキャビティが成長
  • 水深が衝突体天体サイズと同程度 (500 m, 1000 m)
    • 炭酸塩岩層のキャビティがほとんど形成しない
    • 水のキャビティ成長はこれまでと類似
    • 衝突天体成分のターゲットへの埋め込みが見られる.(500 mでの計算例の6 s の図)

キャビティの形状や遷移が他の衝突流体コード(SOVA)を用いた研究[1,2]の計算結果と調和的.

Last modified:2014/04/22 21:44:24
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