venturi: a tube with a constriction; used to control fluid flow (as in the air inlet of a carburetor)
tube: conduit consisting of a long hollow object (usually cylindrical) used to hold and conduct objects or liquids or gases
work: (physics) a manifestation of energy; the transfer of energy from one physical system to another expressed as the product of a force and the distance through which it moves a body in the direction of that force