/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 |
Definitions
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.
- Surface is defined by basis point B=(Bx, By, Bz) and normal vector unless a surface identifier surf_ID is provided. surf_ID is currently only compatible with /SURF/PLANE option in 2018.0 release.
- Pref is the reference pressure
which is measured on reference surface. Usually it is pressure at sea level. Above the
surface pressure is decreasing, below it is increasing using. The pressure change depends
on the signed distance from the reference surface:
(1) Where,- Signed distance
- Reference density of the element
Signed distance is computed from element centroid to reference surface. Initial pressure in a given element is:(2) Where, is the reference density of the given element. - Same pressure value is applied on all integration point of the elements.
- 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 LAW3, 4, 6, 37, 49, 51 (ALE, EULER).
- 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.