The angle of the force used to similate fluid flow.
Fluid flow can be defined to move in any direction with a specific magnitude and a random variation on that magnitude.
This property defines the direction of the force to be applied with the size of the force defined by flowMagnitude and flowVariation.
The flow forces are applied to the center of any submerged region of a Collider2D so it will not produce any torque (rotation) if the Collider2D is fully submerged (fully below the surfaceLevel) but will produce torque if the Collider2D is partially submerged (overlapping the surfaceLevel).
Additional resources: flowMagnitude, flowVariation.