Page 20 - Theory and Design of Air Cushion Craft

Hovercraft beginnings 5

Fig. 1.4 Chinese passenger sidewall hovercraft model 719-1

Fig. 1.5 First Chinese passenger sidewall hovercraft type, Jin Sah River.

Wing-in-ground effect (WIG) and power augmented ram wing
(PARWIG) craft
These craft are rather different from the ACV or SES. They are more like low flying
aircraft, and use ground proximity to increase lift on the specially shaped wing. The
craft are supported by dynamic lift rather than a static cushion.
The WIG (Fig. 1.6) initially floats on the water and its take-off is similar to a sea-
plane. An aeroplane wing operated close to the ground generates lift at the pressur-
ized surface of the wings which is increased significantly due to the surface effect. The
aero-hydrodynamic characteristics of a WIG are therefore a significant optimization
of the design of a seaplane to improve payload.
The PARWIG shown in Fig. 1.7 differs from a WIG by the different location of
lift fans, in which the lift fans (or bow thrusters) are located at the bow and beyond
the air cushion; consequently a large amount of air can be directly injected into the