2022.3

2022.3

/INIV/AXIS/Keyword3/2

Engine Keyword Initialize rotational velocity about an axis and translational velocity on a node set.

Format

/INIV/AXIS/Keyword3/2

Frame_ID

VX^t VY^t VZ^t V^r

grnd_ID

Definition

Field	Contents	Si Unit Example
`Keyword3`	Direction `X`, `Y`, and `Z` of the frame defining the rotation axis.
`Frame_ID`	Frame identifier. (Integer)
`V`_X^t , `V`_Y^t , `V`_Z^t	Translational velocity components in the local frame. (Real)	$[\frac{m}{s}]$ $[\frac{m}{s}]$
`V`^r	Rotational velocity about the axis `Keyword3` in the local frame. (Real)	$[\frac{rad}{s}]$ $[\frac{rad}{s}]$
`grnd_ID`	Node group (/GRNOD) or node set (/SET) on which specific initial velocities are applied.

Comments

If frame_ID is not zero, the initial velocities are applied with respect to this local frame.
Once $V^{t}$ $V^{t}$ is expressed in the global system, the velocities are initialized with respect to:(1)
$v (M) = V^{t} + V^{r} \frac{U}{‖ U ‖} Λ O M$ $v (M) = V^{t} + V^{r} \frac{U}{‖ U ‖} Λ O M$

Where,

$U$ $U$

Vector defining the rotation axis

$O$ $O$

Represents a point on the axis and is set as the origin of the frame.