Card 9 - GRAVITY Gravity Definition

KODE

KODE is the code GRAVITY (or 98)

N1

N1 is the GRAVITY card ID. Cards with the same ID reference the same Gravity definition.

T1

T1 may be:

• T1 = X (or 1) or T = Y (or 2) or T = Z (or 3) represents the X, Y, or Z components of the gravity vector. If a component is constant, then its value is specified in T2. If it is table dependent, then T2 is a table multiplier and T3 has the form Tn (e.g. T25) where n is a table number referencing TABTYPE and TABDATA cards. The dependent variable on the TABTYPE card must be NUMBER, and the independent variable is TIME.
• T1 = MAGNITUDE (or 4) is the magnitude of the gravity acceleration. If the magnitude is constant, then its value is specified in T2. If it is table dependent, then T2 is a table multiplier and T3 has the form Tn (e.g. T25) where n is a table number referencing TABTYPE and TABDATA cards. The dependent variable on the TABTYPE card must be NUMBER, and the independent variable is TIME.

Code example

GRAVITY 1 X 0.0
GRAVITY 1 Y 0.0
GRAVITY 1 Z -1.0
GRAVITY 1 MAGNITUDE 1.0 T25
TABTYPE 25 NUMBER TIME
TABDATA 25 9.81 0.0

Notes

When the MAGNITUDE card is present in a GRAVITY definition, it overrides the magnitude of the gravity vector defined through the X, Y, and Z components. In this case, the components provide the gravity direction only. When the MAGNITUDE card is not present in a GRAVITY definition, both the gravity direction and magnitude are derived from the X, Y, and Z components of the gravity vector.

If a GRAVITY definition is present, it overrides the gravity magnitude and direction in the HYDENV card. If more than one GRAVITY definition is present, a warning is issued and only the first definition is retained.