/INIGRAV
Block Format Keyword Defines initial state from hydrostatic pressure due to gravity loading.
Format
(1) | (2) | (3) | (4) | (5) | (6) | (7) | (8) | (9) | (10) |
---|---|---|---|---|---|---|---|---|---|
/INIGRAV/inigrav_ID/unit_ID | |||||||||
inigrav_title | |||||||||
grpart_ID | surf_ID | grav_ID | |||||||
Pref | Bx | By | Bz |
Definition
Field | Contents | SI Unit Example |
---|---|---|
inigrav_ID | Initial gravity loading
identifier. (Integer, maximum 10 digits) |
|
unit_ID | Optional unit identifier. (Integer, maximum 10 digits) |
|
inigrav_title | Initial gravity loading
title. (Character, maximum 100 characters) |
|
grpart_ID | Group of part identified. If non defined
(0), initial state is applied on all solid PARTs. Default = 0 (Integer) |
|
surf_ID | (Optional) Free surface identifier. If not defined, basis point is read. (Integer) |
|
grav_ID | (Mandatory) Gravity card identifier
used. (Integer) |
|
Pref | Reference pressure on the reference
surface. (Real) |
|
Bx | Basis point X-coordinate (used only if
surf_ID=0). (Real) |
|
By | Basis point Y-coordinate (used only if
surf_ID=0). (Real) |
|
Bz | Basis point Z-coordinate (used only if
surf_ID=0). (Real) |
Example (Water Hydrostatic Pressure)
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/UNIT/1
unit for load
# MUNIT LUNIT TUNIT
g mm ms
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/INIGRAV/1/1
hydrostatique pressure - “ sea level : {Z=0} where Pref=0.101325 MPa
#GRPART_ID SURF_ID GRAV_ID
0 0 1
# Pref Bx By Bz
0.101325 0 0 0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/GRAV/1/1
Terrestrial gravity field
#funct_IDT DIR skew_ID sensor_ID grnod_ID Ascale_x Fscale_Y
2 Z 0 0 5 0 -0.00981
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
/FUNCT/2
unity
# X Y
0 1.0
1000000 1.0
#---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|---10----|
#enddata
Comments
- Gravity value and direction are read from /GRAV card, then grav_ID value is mandatory.
- The surface identifier provides the sea level. surf_ID can either be a /SURF/PLANE (Figure 1) or any other user surface describing the air-water limit (Figure 2). If surf_ID is not provided, then planar surface is assumed by using B=(Bx,By,Bz) as basis point and gravity vector as surface normal.
- Pref is the reference pressure at sea level. Above the surface pressure is decreasing and below the surface pressure is increasing.
- This keyword is computing for each cell in group of part provided by grpart_ID. This initial density is such as pressure changed is where is the signed distance from the sea level. Distance from sea level is computed using cell centroid.
- Mathematical model is such as for each
cell
. This model is only valid if material type is not changing
along the distance (constant reference density).For example: only air above the surface and only water below the surface. Introducing an immersed body into water would require running a computation to solve hydrostatic state in the immersed body.
- If /INIVOL option is used to initialize volumetric fraction with LAW51 then reference density is automatically computed from initial volumetric fractions.
- Currently only compatible with hydrodynamic laws 3, 4, 6, 37, 49, 51, and 151.
- The grav_ID card must reference a gravity /GRAV with a constant gravity function fct_IDT from t=0; or, the function can be left blank and the constant gravity value defined in /GRAV, FscaleY.