To use external forces with nCloth
nCloth reacts to Maya dynamic forces. You can add these external forces to your scene to influence the behavior of your nCloth objects.
To use a 2D or 3D fluid as an external force with nCloth
You can use the Dynamic Relationships Editor to view and edit the connections between the nCloth and fluid objects. When you use a 2D or 3D fluid as an external force with nCloth, the fluid is considered a field rather than a collision object. Therefore, to see the connections between the nCloth and fluid object in the Dynamic Relationship Editor, select Fields as the selection mode. See Dynamic Relationships Editor.